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Lipopolysaccharide induces acute bursal atrophy in broiler chicks by activating TLR4‑MAPK-NF-κB/AP-1 signaling
Abstract
We investigated the mechanisms that induce atrophy of the chicken bursa of Fabricius (BF) upon lipopolysaccharide (LPS) treatment in young chicks. LPS treatment resulted in ~36% decrease in bursal weight within 36 h (P < 0.01). Histological analysis showed infiltration of eosinophilic heterophils and nucleated oval shaped RBCs in or near blood vessels of the BF from LPS-treated chicks. Scanning electron micrographs showed severe erosion and breaks in the mucosal membrane at 12 h and complete exuviation of bursal mucosal epithelial cells at 36 h. We observed decreased cell proliferation (low PCNA positivity) and increased apoptosis (high TUNEL and ssDNA positivity) in the BF 12-72 h after LPS treatment. RNA-seq analysis of the BF transcriptome showed 736 differentially expressed genes with most expression changes (637/736) 12 h after LPS treatment. KEGG pathway analysis identified TLR4-MAPK-NF-κB/AP-1 as the key signaling pathway affected in response to LPS stimulation. These findings indicate LPS activates the TLR4-MAPK-NF-κB/AP-1 signaling pathway that mediates acute atrophy of the chicken bursa of Fabricius by inducing inflammation and apoptosis.
... LPS is a gram-negative bacterial cell wall component that stimulates the immune system and, in large doses, can cause harmful systemic inflammation [22]. Similar to heat stress, experiments using LPS have shown adverse effects on the bursa, including tissue atrophy [23][24][25], and after embryonic exposure, reduced number of bursal follicles [26]. LPS is also well known to impact gene expression in chicken immune tissues, including at the transcriptome level [23,27,28]. ...
... Similar to heat stress, experiments using LPS have shown adverse effects on the bursa, including tissue atrophy [23][24][25], and after embryonic exposure, reduced number of bursal follicles [26]. LPS is also well known to impact gene expression in chicken immune tissues, including at the transcriptome level [23,27,28]. ...
... Bursal responses to a large dose of LPS (50 mg/kg) have previously been characterized by RNA-seq in broilers and identified only 22 of the genes that responded in the current study using a lower dose of LPS (100 μg/kg) [23]. This includes the innate immune genes S100 calcium binding protein A9 (S100A9) and complement component 7 (C7), as well as two of the most up-regulated genes in the Fayoumi Thermoneutral + LPS response, CYR61 and NR4A3. ...
Background:
Exposure to heat stress suppresses poultry immune responses, which can increase susceptibility to infectious diseases and, thereby, intensify the negative effects of heat on poultry welfare and performance. Identifying genes and pathways that are affected by high temperatures, especially heat-induced changes in immune responses, could provide targets to improve disease resistance in chickens. This study utilized RNA-sequencing (RNA-seq) to investigate transcriptome responses in the bursa of Fabricius, a primary immune tissue, after exposure to acute heat stress and/or subcutaneous immune stimulation with lipopolysaccharide (LPS) in a 2 × 2 factorial design: Thermoneutral + Saline, Heat + Saline, Thermoneutral + LPS and Heat + LPS. All treatments were investigated in two chicken lines: a relatively heat- and disease-resistant Fayoumi line and a more susceptible broiler line.
Results:
Differential expression analysis determined that Heat + Saline had limited impact on gene expression (N = 1 or 63 genes) in broiler or Fayoumi bursa. However, Thermoneutral + LPS and Heat + LPS generated many expression changes in Fayoumi bursa (N = 368 and 804 genes). Thermoneutral + LPS was predicted to increase immune-related cell signaling and cell migration, while Heat + LPS would activate mortality-related functions and decrease expression in WNT signaling pathways. Further inter-treatment comparisons in the Fayoumi line revealed that heat stress prevented many of the expression changes caused by LPS. Although fewer significant expression changes were observed in the broiler bursa after exposure to Thermoneutral + LPS (N = 59 genes) or to Heat + LPS (N = 146 genes), both treatments were predicted to increase cell migration. Direct comparison between lines (broiler to Fayoumi) confirmed that each line had distinct responses to treatment.
Conclusions:
Transcriptome analysis identified genes and pathways involved in bursal responses to heat stress and LPS and elucidated that these effects were greatest in the combined treatment. The interaction between heat and LPS was line dependent, with suppressive expression changes primarily in the Fayoumi line. Potential target genes, especially those involved in cell migration and immune signaling, can inform future research on heat stress in poultry and could prove useful for improving disease resistance.
... Following construction of strand-specific libraries, sequencing was done on an Illumina HiSeq 4000 platform by BGI Genomics Co. Ltd. (Shenzhen, China). Differentially expressed genes (DEGs) were screened using the NOISeq method with absolute fold change ≥ 2 and divergent probability ≥ 0 8 [24,25]. The read length was 50 bp. ...
... GO functional classification on DEGs for each pair was conducted following the previously described method [25]. All GO terms are grouped into three ontologies: biological process, cellular component, and molecular function. ...
The thymus is a lobulated unique lymphoid immune organ that plays a critical role in the selection, development, proliferation, and differentiation of T cells. The thymus of developing chickens undergoes continued morphological alterations; however, the biomolecular and transcriptional dynamics of the postnatal thymus in avian species is not clear yet. Therefore, the thymuses from chickens at different stages of development (at weeks 0, 1, 5, 9, 18, and 27) were used in the present study. The RNA-seq method was used to study the gene expression patterns. On average, 24120819 clean reads were mapped, differentially expressed genes (DEGs) were identified on the basis of log values (fold change), including 744 upregulated and 425 downregulated genes. The expression pattern revealed by RNA-seq was validated by quantitative real-time PCR (qPCR) analysis of four important genes, which are PCNA, CCNA2, CCNB2, and CDK1. Thus, the current study revealed that during postnatal development, the thymus undergoes severe atrophy. Thymus structure was damaged and gene expression changed dramatically, especially at the 27 th week of age. Moreover, we found significant changes of several signaling pathways such as the cytokine-cytokine receptor interaction and cell cycle signaling pathways. Hence, it may be inferred that those signaling pathways might be closely related to the postnatal chicken thymus development.
... This can affect the function of the BF, further impacting the reproductive performance of geese and the quality of goslings, which reduces the production quality. Studies found that treatment with LPS activates the TLR4-MAPK-NF-κB/AP-1 signalling pathway, which, in turn, leads to increased apoptosis and decreased cell proliferation within the bursa of Fabricius in broiler chicks, ultimately causing bursal atrophy [9]. Nevertheless, the effects of LPS on the BF in geese remain to be elucidated. ...
The bursa of Fabricius (BF) plays crucial roles in the goslings’ immune system. During waterfowl breeding, the presence of lipopolysaccharides (LPSs) in the environment can induce inflammatory damage in geese. Polysaccharides of Atractylodes macrocephala Koidz (PAMKs), as the main active component of the Chinese medicine Atractylodes macrocephala, have significant immune-enhancing effects. Accordingly, this study intended to investigate the effect of PAMKs on LPS-induced BF injury in goslings. Two hundred 1-day-old goslings (half male and half female) were selected and randomly divided into control, PAMK, LPS, and PAMK + LPS groups. The control and LPS groups were fed the basal diet, and the PAMK and PAMK + LPS groups were fed the basal diet containing PAMKs at 400 mg/kg. The goslings in the LPS and PAMK + LPS groups were injected intraperitoneally with LPS at a concentration of 2 mg/kg on days 24, 26, and 28 of this study. The control and PAMK groups were injected with equal amounts of saline. On the 28th day, 1 h after the LPS injection, the BF and serum were collected and analyzed for organ indices, cytokines, antioxidant indicators, and histological observations. Histological examination and HE staining demonstrated that the PAMK treatment ameliorated the LPS-induced BF atrophy, structural damage, increased cellular exudation, and reticulocyte hyperplasia in the goslings. The cytokine and antioxidant marker analyses in the BF cells demonstrated that the PAMK treatment mitigated the LPS-induced increase in the interleukin-1β (IL-1β), malondialdehyde (MDA), and inducible nitric oxide synthase (iNOS) levels, as well as the decrease in the transforming growth factor-β (TGF-β) and superoxide dismutase (SOD) activities. Further transcriptome sequencing identified a total of 373 differentially expressed genes (DEGs) between the LPS and PAMK + LPS groups. The KEGG enrichment pathway analysis showed that the DEGs were significantly enriched in the Toll-like receptor, p53, MAPK, GnRH, and ErbB signaling pathways. Among them, EREG played key roles in the activation of the MAPK, GnRH, and ErbB signaling pathways. Further research showed that the addition of PAMKs significantly inhibited the LPS-induced EREG expression, increased the cell viability, promoted the cell cycle entry into the S and G2 phases, and inhibited apoptosis. Meanwhile, PAMKs can reduce the protein expression of p-JNKs and c-FOS by inhibiting EREG. In summary, this study found that PAMKs could alleviate LPS-induced BF injury in goslings by inhibiting the expression of EREG.
... Lipopolysaccharide can induce acute bursal atrophy in broilers (Ansari et al., 2017). Present study found that ATL extract alleviated the decreased tend of the bursal index by LPS challenge. ...
This study investigated the appropriate way of dietary Acer truncatum leaves (ATL) addition, the effect of disease prevention and its mechanism of action. In experiment 1, 192 Arbor Acres broilers were assigned to 4 treatment groups, fed with basal diets containing 2% bran, replacing it with primary and fermented ATL, and additional 0.3% ATL extract to the basal diet for 42 d, respectively. In experiment 2, 144 broilers were assigned to 3 treatment groups for 21-d trial: (1) C-N group, basal diets, and injected with 0.9% (w/v) sterile saline; (2) C-L group, basal diets, and injected with lipopolysaccharide (LPS); (3) T-L group, ATL diets and injected with LPS. In experiment 1, ATL significantly decreased the index of abdominal fat at 42 d (P < 0.05). ATL extract had a better ability to improve antioxidant capacity and reduce inflammatory levels among all treatment groups, which significantly decreased the content of MDA in the liver and ileum mucosa at 21 d, and increased the expression of IL-10 and Occludin in jejunal mucosa at 42 d (P < 0.05). In experiment 2, ATL significantly increased the level of T-AOC in the liver, decreased the expression of NF-κB in the jejunal mucosa and ileum mucosa (P < 0.05), and restored LPS-induced the changed level of CAT in jejunal mucosa, the expression of IL-6, Claudin-1, and ZO-1 in jejunal mucosa and IL-1β in ileum mucosa (P < 0.05). Analysis of gut microbiota indicated that ATL enhanced the abundances of Bacteroidota and reduced the proportion of Firmicutes (P < 0.05), and the changed levels of T-AOC in body, IL-1β, IL-6, IL-10, and NF-κB in jejunum mucosa and propionic acid in cecal were associated with gut microbiota. Collectively, our data showed that the extract of ATL had a better antioxidant and anti-inflammatory effects than primality and fermented. Extraction of ATL modulated intestinal microbiota, and had a protective effect on oxidative stress, inflammation, and intestinal barrier function in broilers challenged with LPS.
... The results showed that immune stress significantly decreased growth performance, induced higher relative weight of liver and spleen and lower relative weight of bursa, as well as increased concentration of serum ACTH and CORT. The data obtained here was in agreement with the previous studies (Morales -Lopez and Brufau, 2013;Shen et al., 2010;Liu et al., 2015;Ansari et al., 2017;Zhang et al., 2017a,b). Thus, in this experiment, a model of broiler chicks with immune stress and growth depression was successfully established. ...
Broilers with immune stress show decline of growth performance, causing severe economic losses. However, the molecular mechanisms underlying the immune stress still need to be elucidated. One hundred and twenty broiler chicks were randomly assigned to 2 groups with 6 repeats per group, 10 birds per repeat. The model broilers were intraperitoneally injection of 250 µg/kg LPS at 12, 14, 33, and 35 days of age to induce immunological stress. Control group was injected with an equivalent amount of sterile saline. Blood samples from chickens were collected using wing vein puncture at 35 days of age and the serum was obtained for detection of CORT and ACTH. At the end of the experiment, the liver tissues were excised and collected for omics analysis. The results showed that LPS challenge significantly inhibited growth performance, increased relative weight of liver, spleen and decreased relative weight of bursa, as well as enhanced the concentration of serum ACTH and CORT, when compared with the Control. A total of 129 DEGs and a total of 109 differential metabolites were identified between Model and Control group. Transcriptomics profiles revealed that immune stress enhanced the expression of genes related to defense function while declined the expression of genes related to oxidation-reduction process. Metabolomics further suggested that immune stress changed metabolites related to amino acid metabolism, glycerophospholipid metabolism. In addition, integrated analysis suggested that the imbalance of valine, leucine and isoleucine metabolism, glycerophospholipid metabolism and mTOR signaling pathway played an important role in immune stress of broiler chicks.
... Stromal cell derived factor 21 (CXCL12), a type of chemokines, is also known as proinflammatory cytokines (Balabanian et al., 2005). Previous research indicated that lipopolysaccharide could activate transcriptional expressions of active protein 21 (AP-1), signal translator and activator of transcription 1 (STAT1) and NF-kB (Ansari et al., 2017). In the present study, the above DEGs and NFKBIE were enriched into the Salmonella infection, NOD-like receptor signaling pathway, and Toll-like receptor signaling pathway, which was consistent with the previous study (Geddes et al., 2010). ...
Genistein is abundant in the soybean products, which exerts prominent effects on immune function. Little information is available about the effect of dietary genistein on thymic transcriptome, especially when suffering from lipopolysaccharide challenge. In this study, 180 one-day-old male broilers were randomly allocated to three groups: non-challenged chicks given a basal diet (CON), and lipopolysaccharide-challenged chicks fed a basal diet (LPS), or lipopolysaccharide- challenged chicks fed a basal diet supplemented with 40 mg/kg genistein (GEN). Lipopolysaccharide injection induced thymocyte apoptosis and inflammatory reactions in the chicks. The results showed dietary genistein significantly reduced the percentage of CD3+ T lymphocytes by 10.04 % and CD4+/CD8+ T lymphocyte ratio by 21.88 % in the peripheral blood induced by lipopolysaccharide injection (P < 0.05). In addition, genistein significantly reduced the thymus index by 50 % and apoptotic index by 12.34 % induced by LPS challenge (P <0.05). Transcriptomic analysis identified 1926 DEGs (1014 upregulated and 912 downregulated, P <0.05) between GEN and LPS groups, which altered the mRNA expression profile and signaling pathways (Toll-like receptor, and NOD-like receptor signaling pathway) in the thymus. Furthermore, 5 splicing (AS) isoforms of the Drosophila Disabled-2 (DAB2) gene were detected, which were significantly upregulated in the GEN group compared with that in the LPS group. In summary, dietary genistein supplementation altered the RNA expression profile and AS signatures in the thymus, and alleviated immune response against lipopolysaccharide challenge.
... Usually, the immune reaction in birds upon LPS correlated with pro-inflammatoryresponse via its mediators such as interleukin 6 (IL-6) and avian betadefensin 10 (AvBD10) and inducible nitricoxide synthase (iNOS), thereby LPS injection accelerate RNA expression levels of AvBD10, IL6 and iNOS which is an indicator of pre-treatment with LPS (Ansari et al, 2017;Aoki-Nonaka et al, 2019;Chen et al, 2018;Horvatic et al, 2019;Yang et al, 2019;Song et al, 2019;Zheng et al, 2018). LPS also crucial element for natural immune response during infection which pass the effect on subcellular level (El-Senousey et al, 2018;Horvatic et al, 2019, Khosravi et al, 2018Lucke et al, 2018;Nihashi et al, 2019), which enhance G-VE bacterial infection Dworaczek et al, 2019). ...
Lipopolysaccharides are thought to interact with immune system of birds and is believed to be through lymphocytic immunity, but the actual mechanisms are not yet revealed. The study was designed to unveil the role of Lipopolysaccharide; LPS on broiler-chicken-based immune response during immunization with Infectious Bronchitis Disease; IBD and Newcastle Disease, ND vaccines. For that, 150 "Ross-308" chicks (one-day old) were utilizedand categorized into 5 treatment group, 1 st group received ND vaccine with LPS and IBD vaccine, the 2 nd group, received a ND vaccine and IBD vaccine with LPS, 3 rd group received standard feed and only LPS without any vaccine, 4 th group received ND vaccine with LPS and IBD vaccine with LPS, and 5 th group received standard feed and vaccinated against ND and IBD without LPS treatment. The results revealed a clear improving in immunity parameters specially, in 4 th group that lead us to conclude that LPS are recommended to be used alongside with poultry vaccines.
... Monson et al. [62] studied the effect of aflatoxin B1 and probiotics on turkey spleen transcriptome, and found that the expression level of DOCK10 had no significant different in the group of aflatoxin B1 and the group of probiotics compared with the control group, but it was significantly up-regulated in the group of aflatoxin B1+probiotics compared with the control group. Ansari et al. [63] investigated the mechanisms that induce atrophy of the chicken bursa of fabricius upon lipopolysaccharide (LPS) treatment in young chicks, found that LPS treatment resulted in a significant decrease in the weight of bursa of fabricius, and the decrease of cell proliferation; at the same time, the DOCK10 was significantly up-regulated. This suggests that DOCK10, as a proinflammatory factor, its high expression can induce abnormal apoptosis. ...
The aim of this study was to construct the spleen differential genes library of broilers fed with probiotic Bacillus cereus PAS38 by suppression subtractive hybridization (SSH) and screen the immune-related genes. Sixty seven-day-old broilers were randomly divided into two groups. The control group was fed with basal diet, and the treated group was fed with basal diet containing Bacillus cereus PAS38 1×10⁶ CFU/g. Spleen tissues were taken and extracted its total RNA at 42 days old, then SSH was used to construct differential gene library and screen immune-related genes. A total of 119 differentially expressed sequence tags (ESTs) were isolated by SSH and 9 immune-related genes were screened out by Gene ontology analysis. Nine differentially expressed genes were identified by qRT-PCR. JCHAIN, FTH1, P2RX7, TLR7, IGF1R, SMAD7, and SLC7A6 were found to be significantly up-regulated in the treated group. Which was consistent with the results of SSH. These findings imply that probiotic Bacillus cereus PAS38-induced differentially expressed genes in spleen might play an important role in the improvement of immunity for broilers, which provided useful information for further understanding of the molecular mechanism of probiotics responsible to affect the poultry immunity.
... These activities tend to reduce cellular proliferation and hence reduced bursa weight (Xie et al., 2000). The reduced bursa weight observed in broilers not receiving any of the test additives, but that were challenged with LPS (NC group) compared to all other treatment groups in the present study is consistent with the findings of Xie et al. (2000) and Ansari et al. (2017), that also reported that LPS challenge markedly reduced bursal weight in LPS-challenged broiler chickens compared to the control group. At the end of the experiment (day 35), there was no observed difference in the relative weight of the spleen, bursa, and liver between the different treatment groups. ...
The objective of this study was to assess the effect of dietary yeast products on broiler chickens challenged with salmonella lipopolysaccharide (LPS). The chicks were divided into 8 treatments with 6 replicates and 9 birds per replicate. The treatments consisted of a positive control (PC) [without supplementation and not challenged]; negative control (NC) [without supplementation but challenged]; whole yeast and challenged; yeast cell wall and challenged; yeast glucan and challenged; yeast mannan and challenged; zinc bacitracin and challenged; and Salinomycin and challenged. Whole yeast or Yeast cell wall was included at 2.0 g/kg diet. Yeast glucan or mannan was added at 0.20 g/kg diet. Zinc bacitracin (ZNB) and Salinomycin (SAL) was included at 50 and 60 ppm, respectively. Dietary treatments had no effect (P > 0.05) on feed intake (FI) at day 10. Supplementation with yeast and its derivatives improved (P < 0.05) body weight gain (BWG) and feed conversion ratio (FCR) on day 10. On days 24 and 35, LPS challenge declined FI, BWG, FCR, and flock uniformity (day 28) in the NC group compared to the PC group. Yeast products and antibiotics improved (P < 0.05) FI, BWG, FCR, and flock uniformity in LPS-challenged birds. On day 24, spleen weight increased while bursa weight decreased in the NC group relative to the PC group; this effect was reversed (P < 0.05) by feeding all yeasts and antibiotics. On day 24, application of all the dietary treatments ameliorated the changes observed in white blood cell, lymphocyte and monocyte counts as well as albumin and immunoglobulin G of NC birds. On day 35, all yeasts additives, ZNB and SAL improved (P < 0.05) the meat yield of broilers challenged with LPS. In conclusion, supplementation of diets with yeast and its derivatives can ameliorate the negative effects of salmonella LPS challenge on broiler chicks, thus improving the performance, flock uniformity, and meat yield.
... These activities tend to reduce cellular proliferation and hence reduced bursa weight (Xie et al., 2000). The reduced bursa weight observed in broilers not receiving any of the test additives, but that were challenged with LPS (NC group) compared to all other treatment groups in the present study is consistent with the findings of Xie et al. (2000) and Ansari et al. (2017), that also reported that LPS challenge markedly reduced bursal weight in LPS-challenged broiler chickens compared to the control group. At the end of the experiment (day 35), there was no observed difference in the relative weight of the spleen, bursa, and liver between the different treatment groups. ...
Objective:
This study evaluated the effect of yeast products on growth performance, visceral organ weights, endogenous enzyme activities, ileal nutrient digestibility and meat yield of broiler chickens fed diets containing autolyzed whole yeast (WY) and yeast cell walls (YCW) at varying levels of inclusion.
Methods:
Nine dietary treatments consisting of WY or YCW included at 0.5, 1.0, 1.5 or 2.0 g/kg diet and a control diet without yeast supplementation was used in the experiment. Each of the nine treatments was replicated six times with nine birds per replicate. Birds were housed in cages, in climate-controlled rooms and fed starter, grower and finisher diets.
Results:
There was an improvement (p<0.05) in body weight gain (BWG) and feed conversion ratio (FCR) on d 10, 24 and 35 for birds fed 1.0-2.0 g/kg WY or YCW diet. Small intestine weight was heavier on d 10 and 24 for birds on higher levels of WY and YCW compare to the control group. On d 10 and 24, there was a significant increase (p<0.05) in tissue protein content and pancreatic enzyme activities (trypsin and chymotrypsin) of birds on 1.5-2.0 g/kg WY and YCW diets compared to the control group. Compared to the control group, birds on WY (2.0 g/kg diet) and YCW (at 1.5 and 2.0 g/kg diet) had better (p<0.05) protein digestibility on d 24. On d 35, there was significant improvement (p<0.05) in percentage of carcass, absolute and relative breast weight for broiler chickens fed WY and YCW mostly at 2 g/kg diet compared to birds on the control diet.
Conclusion:
Supplementation of diets with autolyzed WY and YCW products especially at 1.5-2.0 g/kg diet improved broiler chicken performance and meat yield through their positive effects on ileal protein digestibility and pancreatic enzyme activities.
... The chicks were intra-peritoneally (i.p.) injected with LPS derived from Salmonella enterica serovar Typhimurium (STm) (L7261; Sigma-Aldrich, St. Louis, MO, USA) at 50 mg/kg of body weight in 0.5 mL avian saline solution (0.75% NaCl). The chicks in the control group were injected with 0.5 mL avian saline solution only [22]. ...
Spleen is one of the crucial sites for cellular and humoral immunity but it easily damaged during pathogenic infections resulting in immunosuppression. The current study was therefore performed to explore the mechanism of acute spleen injury induced by salmonella lipopolysaccharide (LPS) in young chicks. Healthy one-day-old Cobb strain broiler chicks were intra-peritoneally injected with saline or LPS. LPS treatment caused significant decreases in body and spleen weights at 36 and 72 h. Histological analysis showed the changes of ellipsoid structures with beginning of nuclear pyknosis and karyolysis similar to steatosis at 12 h, maximum histopathological lesions were seen at 36 h, however these were disappeared at 72 h post LPS stimulation. Cell proliferation was decreased (low PCNA positivity) and apoptosis increased (high ssDNA positivity) in the spleen at 12 and 36 h after LPS treatment. The expression levels of mRNA for caspase-3, caspase-8, B-cell lymphoma 2 (BCL-2), tumor protein p53 or p53 and Bcl-2 homologous antagonist killer (BAK) showed slight increase at some time points following LPS stimulation. LPS treatment also induced significant up-regulation in toll like receptor 4 (TLR4) at 36 h post LPS stimulation and slight increase in expressions of its downstream molecules (MyD88 and NF-κB) at 12 h post LPS treatment. The keystone cytokines (TNF-α and IL-6) exhibited significant up-regulation at 12 h following LPS stimulation. Our findings provided novel information about the histopathological as well as apoptotic and proliferative alterations in spleen mediated by TLR4 signaling induced by Salmonella LPS in avian species.
In the present study, lipid-A gene mutants of Salmonella gallinarum (SG) were screened, and the arnT mutant exhibited optimal acidic and oxidative-stress and macrophage-survival. Modifying lipid-A by arnT-deletion resulted in significantly reduced endotoxicity, virulence, and mortality. Therefore, the arnT-deleted vaccine-candidate strain JOL2841 was constructed and demonstrated to be safe due to appropriate clearance by the chicken immune system. The reduced-endotoxicity of JOL2841 was evident from the downregulation of TNFα and IL-1β inflammatory cytokines, no inflammatory signs in organ gross-examination, and histopathological analysis. The IgY and IgA antibody titres, CD4, and CD8 T-cell population improvements, and IL-4, IL-2, and INFγ expression decipher the profound Th2 and Th1 immunogenicity. Consequently, JOL2841 exhibited prominent protection against wild-type SG challenge, as revealed by organ pathogen-load determination, organ gross-examination, and histopathological examination. Overall, the study represented the first report of arnT deficient SG resulted in negligible endotoxicity, low-virulence, safety and coordinated elicitation of humoral and cell-mediated immune response in chickens.
The chick immune system is a fundamental model in basic immunology. In birds, the bone marrow derived pluripotent stem cells after entering the circulation, migrate to bursa of Fabricius to benefit from a microenvironment which supports the differentiation and maturation of B lymphocytes by the help of its resident cells and tissues. Delivering sufficient functional B cells is required to maintain their peripheral population and normal peripheral humoral responses. Additionally, bursa acts as an active site for the generation of antibody diversity through gene conversion. Being consisted of 98% B lymphocytes, the organ is occupied by other cell types including T cells, macrophages, eosinophils and mast cells. Thymus, which is an epithelial organ is the main site of T cell development where positive and negative selections contribute to the development of functional and not autoreactive T cell repertoire. Bursectomy and thymectomy are surgical exercises through which the involvement of cells of specific immunity including B cells and T cells can be determined.
Psoriasis is a chronic and benign proliferative skin disease. Flavonoids in chenpi (aged tangerine peel) from tangerine (Citrus reticulate Blanco), such as nobiletin (Nob), tangeretin, and 5-hydroxy-6,7,8,3′,4′-pentamethoxyflavone (5-HPMF), possess anti-inflammation and regulation of immune activity among others. In this study, psoriasis-like skin lesions were induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), and the preventive effect of Nob and 5-HPMF on psoriasis-like skin lesions was evaluated. Results showed that skin lesions were dramatically reduced by Nob and 5-HPMF. Levels of cytokines, including interleukin (IL)-1β, IL-17, IL-4, IL-6, tumor necrosis factor-α, and interferon-γ, were also reduced after Nob and 5-HPMF treatment. The expression levels of p-ERK1/2 and p-p38 mitogen-activated protein kinase (MAPK) in the TPA group were 5.3, 4.8, and 5.7 but downregulated to 2.7, 2.9, and 2.3 in the Nob group and 2.4, 2.7, and 1.2 in the 5-HPMF group, respectively (p ≤ 0.05). The expression of transcription factors Ki-67 and proliferating cell nuclear antigen (PCNA) and the differentiation of CD4⁺ T cells were reduced by downregulating the expression of the MAPK signaling pathways. The expression levels in TPA, Nob, and 5-HPMF groups were 0.649 ± 0.094, 0.218 ± 0.034, and 0.193 ± 0.042 for Ki-67 and 0.753 ± 0.114, 0.315 ± 0.094, and 0.294 ± 0.035 for PCNA, respectively. Moreover, 5-HPMF showed stronger reduction activity in the prevention of psoriasis than Nob, indicating that the 5-hydroxyl group facilitated the suppression of psoriasis.
This study was conducted with objective of evaluating the toxic effects of nickel chloride (NiCl2) on development of bursa of Fabricius in broilers fed on diets supplemented with 0, 300, 600 and 900 mg/kg of NiCl2 for 42 days by using the methods of experimental pathology, flow cytometry (FCM), and quantitative real-time polymerase chain reaction (qRT-PCR). The results showed that dietary NiCl2 in 300 mg/kg and over induced toxic suppression in the bursal development, which was characterized by decreasing lymphocytes histopathologically and relative weight, increasing G0/G1 phase (a prolonged nondividing state), reducing S phase (DNA replication) and proliferating index, and increasing percentages of apoptotic cells. Concurrently, the mRNA expression levels of bax, cytochrome c (cyt c), apoptotic peptidase activating factor 1 (Apaf-1), caspase-3, caspase-6, caspase-7 and caspase-9 were increased and the bcl-2 mRNA expression levels were decreased. The toxic suppression of bursal development finally impaired humoral immunity duo to the reduction of B lymphocyte population and B lymphocyte activity in the broiler chicken. This study provides new evidences for further studying the effect mechanism of Ni and Ni compoundson B-cell or bursa of Fabricius.
Over activation of microglia results in the production of proinflammatory agents that have been implicated in various brain diseases. Pycnogenol is a patented extract from French maritime pine bark (Pinus pinaster Aiton) with strong antioxidant and anti-inflammatory potency. The present study investigated whether pycnogenol may be associated with the production of proinflammatory mediators in lipopolysaccharide-stimulated BV2 (mouse-derived) microglia. It was found that pycnogenol treatment was dose-dependently associated with significantly less release of nitricoxide (NO), TNF-α, IL-6 and IL-1β, and lower levels of intercellular adhesion molecule1 (ICAM-1) and perilipin 2 (PLIN2). Furthermore, this effect was replicated in primary brain microglia. Levels of inducible NO synthase mRNA and protein were attenuated, whereas there was no change in the production of the anti-inflammatory cytokine IL-10. Further evidence indicated that pycnogenol treatment led to the suppression of NF-κB activation through inhibition of p65 translocation into the nucleus and inhibited DNA binding of AP-1, suggesting that these proinflammatory factors are associated with NF-κB and AP-1. We conclude that pycnogenol exerts anti-inflammatory effects through inhibition of the NF-κB and AP-1pathway, and may be useful as a therapeutic agent in the prevention of diseases caused by over activation of microglia.
Scavenger receptor associated with endothelial cells I (SREC-I) was shown to be expressed in immune cells and to play a role in the endocytosis of peptides and antigen presentation. As our previous studies indicated that SREC-I required intact Toll-like receptor 4 (TLR4) expression for its functions in tumor immunity, we examined potential interactions between these two receptors. We have shown here that SREC-I became associated with TLR4 on binding bacterial lipopolysaccharides (LPS) in RAW 264.7 and HEK 293 cells overexpressing these two receptors. The receptors then became internalized together in intracellular endosomes. SREC-I promoted TLR4-induced signal transduction through the NF-kB and MAP kinase pathways, leading to enhanced inflammatory cytokine release. Activation of inflammatory signaling through SREC-I/TLR4 complexes appeared to involve recruitment of the receptors into detergent-insoluble, cholesterol-rich lipid microdomains that contained the small GTPase Cdc42 and the non-receptor tyrosine kinase c-src. Under conditions of SREC-I activation by LPS, TLR4 activity required Cdc42 as well as cholesterol and actin polymerization for signaling through NF-kB and MAP kinase pathways in RAW 264.7 cells. SREC-I appeared to respond differently to another ligand, the molecular chaperone Hsp90 that, while triggering SREC-I-TLR4 binding caused only faint activation of the NF-kB pathway. Our experiments therefore indicated that SREC-I could bind LPS and might be involved in innate inflammatory immune responses to extracellular danger signals in RAW 264.7 cells or bone marrow-derived macrophages.
Toll-like receptors (TLRs) and nucleotide binding and oligomerization domain (NOD) receptors are pattern recognition receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) and play crucial role in innate immunity. In addition to PAMPs, PRRs recognize endogenous molecules released from damaged tissue or dead cells [damage-associated molecular patterns (DAMPs)] and activate signaling cascades to induce inflammatory processes. In the aquatic environment, large variation in seasonal and diurnal water temperature causes heat and cold stresses in fish, resulting in tissue injury and mortality of fish. In the Indian subcontinent, catla (Catla catla) is an economically important freshwater fish species and is prone to thermal stresses. To investigate the response of pattern recognition receptors in thermal stress, we analyzed TLRs (TLR2, TLR4 and TLR5) and NOD (NOD1 and NOD2) receptors gene expression in catla following heat and cold stress. Analysis of tissue samples (gill, liver, kidney and blood) of the thermal stressed and control fish by quantitative real-time PCR (qRT-PCR) assay revealed significant (p
Fowl typhoid (FT) is a septicemic disease of poultry that causes considerable economic losses through mortality and increased morbidity. Infection of birds of all ages, in the field or experimentally , can result in very high mortality (5, 10). The disease is caused by the gram-negative bacterium Salmonella enterica sero-var Gallinarum (31), a member of the Enterobacteriaceae family which is widely distributed throughout the world (34). Salmonella Gallinarum is highly adapted and seldom causes significant problems in hosts other than chickens, turkeys and pheasants (30, 34). No difference in susceptibility to Salmonella Gallinarum has been observed between local and commercial chickens (26). It was formerly known as Shigella gallinarum, when first isolated by Klein in England in 1889 (30). The disease was called fowl typhoid in 1902 (31). FT has been eradicated in the commercial poultry production of developed countries, but is still a major problem in developing countries (22). In India, FT has long been plaguing the poultry industry, causing heavy economic losses due to mortality in young and adult chickens. Since it was first reported by Cooper and Naik (9) in India, the incidence of FT is on the increase and illustrated by the fact that Salmonella Gallinarum alone accounted for 32% of Salmonella of avian origin typed at the National Salmonella Centre (Veterinary), Izatnagar, India, from 1987 to 1995 (14). Salmonella Gallinarum has been found to be the predominant serotype and the major cause of mortality in poultry in India (28, 32).
Fowl adenoviruses (FAdVs) cause disease in domestic chickens, including inclusion body hepatitis (IBH), with immunosuppression believed to play a role in their pathogenesis. To gain a better understanding of the pathogenesis and chronology of disease caused by FAdVs, the gross pathology, histopathology and dissemination of virus were examined in several different time points, after inoculation of one-day-old specific-pathogen-free chickens with FAdV-1, FAdV-8b or FAdV-11 via the ocular route. FAdV-8b had slightly greater virulence than FAdV-11, but both were primary pathogens. The presence and severity of hepatic lesions were used to define the three stages of the disease: incubation (1-3 days post-inoculation), degeneration (4-7 days post-inoculation) and convalescence (14 days post-inoculation). Both viruses were detected in the liver, kidney, bursa, thymus and gizzard of most birds during the degenerative stage, and persisted in the gizzard into convalescence. The FAdV-1 isolate was found to be apathogenic, but virus was detected in the bursa and/or gizzard of several birds between 2 and 7 days post-inoculation. This is the first study examining the chronology of gross and microscopic lesions of pathogenic and apathogenic FAdVs in association with viral presence in multiple tissues. It was concluded that both FAdV-8b and FAdV-11 are primary pathogens, and that these strains may play a role in immunosuppression.
This study was conducted to investigate the effect of feeding a probiotic, Bacillus subtilis, on antibody titers against Newcastle and infectious bursal viruses in broiler chickens challenged with Salmonella enterica serotype Enteritidis. One hundred and sixty 1-day-old broiler chicks were randomly assigned to four treatments in a completely randomized design. The treatments were negative control, probiotic-treated group, challenged group, and challenged probiotic treated group. Salmonella challenging decreased (P < 0.05) the relative weights of spleen and bursa. Inclusion of probiotic to diet of challenged chickens increased the relative weight of spleen, but had no effect on the relative weight of bursa. There were no differences for the antibody titers of chickens between negative control and probiotic-treated group. Salmonella challenging decreased (P < 0.05) antibody titers against Newcastle and infectious bursal viruses. Improvements in the antibody titers were observed by the addition of probiotic to diet of these chickens. The results showed that dietary inclusion of probiotic had no significant effect on immune parameters of chickens at non-contaminated environment, display a greater efficacy at environment contaminated with pathogen and can improve immune responses of infected chickens.
A recent focus meeting on Controlling Acute Inflammation was held in London, April 27-28, 2006, organized by D.W. Gilroy and S.D. Brain for the British Pharmacology Society. We concluded at the meeting that a consensus report was needed that addresses the rapid progress in this emerging field and details how the specific study of resolution of acute inflammation provides leads for novel anti-inflammatory therapeutics, as well as defines the terms and key components of interest in the resolution process within tissues as appreciated today. The inflammatory response protects the body against infection and injury but can itself become dysregulated with deleterious consequences to the host. It is now evident that endogenous biochemical pathways activated during defense reactions can counter-regulate inflammation and promote resolution. Hence, resolution is an active rather than a passive process, as once believed, which now promises novel approaches for the treatment of inflammation-associated diseases based on endogenous agonists of resolution.--Serhan, C. N., Brain, S. D., Buckley, C. D., Gilroy, D. W., Haslett, C., O'Neill, L. A. J., Perretti, M., Rossi, A. G., Wallace, J. L. Resolution of inflammation: state of the art, definitions and terms.
Gram-negative bacteria including Escherichia coli, Citrobacter rodentium, Salmonella typhimurium, and Shigella flexneri are sensed in an ill-defined manner by an intracellular inflammasome complex that activates caspase-11. We show that macrophages
loaded with synthetic lipid A, E. coli lipopolysaccharide (LPS), or S. typhimurium LPS activate caspase-11 independently of the LPS receptor Toll-like receptor 4 (TLR4). Consistent with lipid A triggering
the noncanonical inflammasome, LPS containing a divergent lipid A structure antagonized caspase-11 activation in response
to E. coli LPS or Gram-negative bacteria. Moreover, LPS-mutant E. coli failed to activate caspase-11. Tlr4–/– mice primed with TLR3 agonist polyinosinic:polycytidylic acid [poly(I:C)] to induce pro-caspase-11 expression were as susceptible
as wild-type mice were to sepsis induced by E. coli LPS. These data unveil a TLR4-independent mechanism for innate immune recognition of LPS.
Thymic atrophy is a frequent consequence of infection with bacteria, viruses, and parasites and is considered a common virulence trait between pathogens. Multiple reasons have been proposed to explain this atrophy, including premature egress of immature thymocytes, increased apoptosis, or thymic shutdown to prevent tolerance to the pathogen from developing. The severe loss in thymic cell number can reflect an equally dramatic reduction in thymic output, potentially reducing peripheral T cell numbers. In this study, we examine the relationship between systemic Salmonella infection and thymic function. During infection, naive T cell numbers in peripheral lymphoid organs increase. Nevertheless, this occurs despite a pronounced thymic atrophy caused by viable bacteria, with a peak 50-fold reduction in thymocyte numbers. Thymic atrophy is not dependent upon homeostatic feedback from peripheral T cells or on regulation of endogenous glucocorticoids, as demonstrated by infection of genetically altered mice. Once bacterial numbers fall, thymocyte numbers recover, and this is associated with increases in the proportion and proliferation of early thymic progenitors. During atrophy, thymic T cell maturation is maintained, and single-joint TCR rearrangement excision circle analysis reveals there is only a modest fall in recent CD4(+) thymic emigrants in secondary lymphoid tissues. Thus, thymic atrophy does not necessarily result in a matching dysfunctional T cell output, and thymic homeostasis can constantly adjust to systemic infection to ensure that naive T cell output is maintained.
The Gene Ontology (GO) project (http://www. geneontology.org/) provides structured, controlled vocabularies and classifications that cover several domains of molecular and cellular biology
and are freely available for community use in the annotation of genes, gene products and sequences. Many model organism databases
and genome annotation groups use the GO and contribute their annotation sets to the GO resource. The GO database integrates
the vocabularies and contributed annotations and provides full access to this information in several formats. Members of the
GO Consortium continually work collectively, involving outside experts as needed, to expand and update the GO vocabularies.
The GO Web resource also provides access to extensive documentation about the GO project and links to applications that use
GO data for functional analyses.
Terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) assay has been designed to detect apoptotic cells that undergo extensive DNA degradation during the late stages of apoptosis. The method is based on the ability of TdT to label blunt ends of double-stranded DNA breaks independent of a template. This chapter describes an assay for detection of apoptotic cells during mouse odontogenesis using a colorimetric TUNEL system.
Next-generation sequencing (NGS) technologies are revolutionizing genome research, and in particular, their application to transcriptomics (RNA-seq) is increasingly being used for gene expression profiling as a replacement for microarrays. However, the properties of RNA-seq data have not been yet fully established, and additional research is needed for understanding how these data respond to differential expression analysis. In this work, we set out to gain insights into the characteristics of RNA-seq data analysis by studying an important parameter of this technology: the sequencing depth. We have analyzed how sequencing depth affects the detection of transcripts and their identification as differentially expressed, looking at aspects such as transcript biotype, length, expression level, and fold-change. We have evaluated different algorithms available for the analysis of RNA-seq and proposed a novel approach--NOISeq--that differs from existing methods in that it is data-adaptive and nonparametric. Our results reveal that most existing methodologies suffer from a strong dependency on sequencing depth for their differential expression calls and that this results in a considerable number of false positives that increases as the number of reads grows. In contrast, our proposed method models the noise distribution from the actual data, can therefore better adapt to the size of the data set, and is more effective in controlling the rate of false discoveries. This work discusses the true potential of RNA-seq for studying regulation at low expression ranges, the noise within RNA-seq data, and the issue of replication.
The article "The bursa of Fabricius and antibody production" by Bruce Glick, Timothy S. Chang, and R. George Jaap first demonstrated the role of the bursa in immune development. Birds, including chickens, possess a peculiar organ, the bursa of Fabricius. The organ was recognized for more than 300 yr before its function was described in 1956. Discovery of the bursa as an essential component of the immune response began by accident. Removal of the bursa, bursectomy, during the rapid growth period diminished the antibody response to Salmonella. A paper describing this exceptional finding was initially rejected by Science and ultimately published in Poultry Science. This revelation triggered sequential events leading to the understanding of the dichotomy of the immune response. Additional work in multiple laboratories over many years revealed fundamental immune mechanisms attributable to the bursa. Understanding those mechanisms advanced agricultural and biomedical science.
Mechanisms governing the normal resolution processes of inflammation are poorly understood, yet their elucidation may lead to a greater understanding of the pathogenesis of chronic inflammation. The removal of neutrophils and their potentially histotoxic contents is one prerequisite of resolution. Engulfment by macrophages is an important disposal route, and changes in the senescent neutrophil that are associated with their recognition by macrophages are the subject of this investigation. Over 24 h in culture an increasing proportion of human neutrophils from peripheral blood or acutely inflamed joints underwent morphological changes characteristic of programmed cell death or apoptosis. Time-related chromatin cleavage in an internucleosomal pattern indicative of the endogenous endonuclease activation associated with programmed cell death was also demonstrated. A close correlation was observed between the increasing properties of apoptosis in neutrophils and the degree of macrophage recognition of the aging neutrophil population, and a direct relationship between these parameters was confirmed within aged neutrophil populations separated by counterflow centrifugation into fractions with varying proportions of apoptosis. Macrophages from acutely inflamed joints preferentially ingested apoptotic neutrophils and histological evidence was presented for occurrence of the process in situ. Programmed cell death is a phenomenon of widespread biological importance and has not previously been described in a cell of the myeloid line. Because it leads to recognition of intact senescent neutrophils that have not necessarily disgorged their granule contents, these processes may represent a mechanism for the removal of neutrophils during inflammation that also serves to limit the degree of tissue injury.
The effects of Salmonella typhimurium lipopolysaccharide (LPS) on the physiology of 3-wk-old broiler chickens were studied at 12, 24, and 48 h after a single intravenous injection of saline or LPS. Lipopolysaccharide elevated cloacal temperature by 3 h after injection, induced a diuretic response, and decreased BW gain. An increase in the relative liver weight was evident in LPS-treated birds at all time intervals, whereas a decrease in the relative weight of bursa of Fabricius was observed only at the 48-h time point. The plasma interleukin (IL)-6 and the blood heterophil concentrations were elevated at 12 and 24 h following LPS administration. These changes were not observed in control chickens or in LPS-treated chickens at 48 h. A decrease in the blood glucose concentration in LPS-treated birds at 12 h was accompanied by an elevation in the blood phosphate level. An increase in total plasma protein concentration was observed only at 24 and 48 h after LPS treatment. Comparative SDS-PAGE analysis of plasma proteins from these birds under nonreducing conditions showed some quantitative differences in four bands of proteins between saline and LPS-treated chickens. A protein corresponding to an approximate molecular weight (MW) of 65 kDa increased in LPS-treated chickens, and three other proteins with MW of approximately 39, 49, and 56 kDa showed reductions in concentration compared with saline-treated controls. These results show that LPS induces a number of physiological changes that may be responsible for the regulation of the acute phase response in chickens.
Infectious bursal disease virus (IBDV) is an important immunosuppressive virus of chickens. The virus is ubiquitous and, under natural conditions, chickens acquire infection by the oral route. IgM+ cells serve as targets for the virus. The most extensive virus replication takes place in the bursa of Fabricius. The acute phase of the disease lasts for about 7-10 days. Within this phase, bursal follicles are depleted of B cells and the bursa becomes atrophic. Abundant viral antigen can be detected in the bursal follicles and other peripheral lymphoid organs such as the cecal tonsils and spleen. CD4(+) and CD8(+) T cells accumulate at and near the site of virus replication. The virus-induced bursal T cells are activated, exhibit upregulation of cytokine genes, proliferate in response to in vitro stimulation with IBDV and have suppressive properties. Chickens may die during the acute phase of the disease although IBDV induced mortality is highly variable and depends, among other factors, upon the virulence of the virus strain. Chickens that survive the acute disease clear the virus and recover from its pathologic effects. Bursal follicles are repopulated with IgM(+) B cells. Clinical and subclinical infection with IBDV may cause immunosuppression. Both humoral and cellular immune responses are compromised. Inhibition of the humoral immunity is attributed to the destruction of immunoglobulin-producing cells by the virus. Other mechanisms such as altered antigen-presenting and helper T cell functions may also be involved. Infection with IBDV causes a transient inhibition of the in vitro proliferative response of T cells to mitogens. This inhibition is mediated by macrophages which are activated in virus-exposed chickens and exhibit a marked enhancement of expression of a number of cytokine genes. We speculate that T cell cytokines such as interferon (IFN)-gamma may stimulate macrophages to produce nitric oxide (NO) and other cytokines with anti-proliferative activity. Additional studies are needed to identify the possible direct immunosuppressive effect of IBDV on T cells and their functions. Studies are also needed to examine effects of the virus on innate immunity. Earlier data indicate that the virus did not affect normal natural killer (NK) cell levels in chickens.
This study attempted to evaluate the effect of various housing densities and perch availability on the immune status of commercial broilers. Birds were raised from hatch to 42 d of age with 10, 15, and 20 birds/m2 in pens, with and without the availability of horizontal perches. The immune parameters that were assessed were lymphoid organ weights, antibody response to SRBC in the last 10 d of growth, heterophil:lymphocyte ratios at 32 and 42 d of age, and lymphocyte blastogenesis of peripheral blood lymphocytes collected at 32 and 42 d of age. As density increased, bursa weight and bursa/body weight ratios decreased significantly (P < 0.05). Addition of perches to the pens also significantly decreased the bursa weights and bursa/body weight index (P < 0.01). No other significant effects were observed for the flock performance, morphometric data, or immunological tests between treatments. We concluded that under the conditions of this study, which tried to simulate commercial conditions, the bursal weight was the best indicator of stress that was related to housing density. Addition of perches appeared to increase this level of stress because the birds used the perches infrequently, and therefore there might have been a further reduction in the availability of floor space to the birds.
Population dynamics of intestinal lymphocytes and the temporal development of lymphocyte functions were studied in broiler chicks during the first 2 weeks post-hatch. This period is of major immunological importance as the chick is immediately exposed to environmental antigens and pathogens. We show that the gut-associated lymphoid tissue contains functionally immature T and B lymphocytes at hatch, and that function is attained during the first 2 weeks of life as demonstrated by mRNA expression of both ChIL-2 and ChIFNgamma. Functional maturation occurred in two stages: the first-during the first week post-hatch, and the second during the second week, which was also accompanied by an increase in lymphocyte population, as determined by expression of antigen receptor genes. Evidence is presented to show that in the intestinal milieu cellular immune responses mature earlier, and are a prerequisite for humoral responses. Hence, the lack of antibody response in young chicks is primarily due to immaturity of T lymphocytes.
Toll-like receptor 4 (TLR4) is part of a group of evolutionarily conserved pattern recognition receptors involved in the activation
of the immune system in response to various pathogens and in the innate defense against infection. We describe here the cloning
and characterization of the avian orthologue of mammalian TLR4. Chicken TLR4 encodes a 843-amino-acid protein that contains a leucine-rich repeat extracellular domain, a short transmembrane domain typical
of type I transmembrane proteins, and a Toll-interleukin-1R signaling domain characteristic of all TLR proteins. The chicken
TLR4 protein shows 46% identity (64% similarity) to human TLR4 and 41% similarity to other TLR family members. Northern blot
analysis reveals that TLR4 is expressed at approximately the same level in all tissues tested, including brain, thymus, kidney, intestine, muscle, liver,
lung, bursa of Fabricius, heart, and spleen. The probe detected only one transcript of ca. 4.4 kb in length for all tissues
except muscle where the size of TLR4 mRNA was ca. 9.6 kb. We have mapped TLR4 to microchromosome E41W17 in a region harboring the gene for tenascin C and known to be well conserved between the chicken
and mammalian genomes. This region of the chicken genome was shown previously to harbor a Salmonella susceptibility locus. By using linkage analysis, TLR4 was shown to be linked to resistance to infection with Salmonella enterica serovar Typhimurium in chickens (likelihood ratio test of 10.2, P = 0.00138), suggesting a role of TLR4 in the host response of chickens to Salmonella infection.
Poultry meat and eggs contaminated with Salmonella enterica serovar Enteritidis or Salmonella enterica serovar Typhimurium are common sources of acute gastroenteritis in humans. However, the exact nature of the immune mechanisms
protective against Salmonella infection in chickens has not been characterized at the molecular level. In the present study, bacterial colonization, development
of pathological lesions, and proinflammatory cytokine and chemokine gene expression were investigated in the liver, spleen,
jejunum, ileum, and cecal tonsils in newly hatched chickens 6, 12, 24, and 48 h after oral infection with Salmonella serovar Typhimurium. Very high bacterial counts were found in the ileum and cecal contents throughout the experiment, whereas
Salmonella started to appear in the liver only from 24 h postinfection. Large numbers of heterophils, equivalent to neutrophils in mammals,
and inflammatory edema could be seen in the lamina propria of the intestinal villi and in the liver. Interleukin 8 (IL-8),
K60 (a CXC chemokine), macrophage inflammatory protein 1 β, and IL-1β levels were significantly upregulated in the intestinal
tissues and in the livers of the infected birds. However, the spleens of the infected birds show little or no change in the
expression levels of these cytokines and chemokines. Increased expression of the proinflammatory cytokines and chemokines
(up to several hundred-fold) correlated with the presence of inflammatory signs in those tissues. This is the first description
of in vivo expression of chemokines and proinflammatory cytokines in response to oral infection with Salmonella in newly hatched chickens.
Trichotecene poisoning in poultry can cause oral lesions, haemorrhages, depletion and necrosis in the lymphopoetic organs and death. Spontaneous poisonings with these toxins are rarely described. This paper describes the spontaneous poisoning of two Brahma chickens with T-2 toxin, diacetoxyscirpenol and deoxynivalenol. Two out of 10 chickens died under signs of depression and loss of appetite. Histopathological analysis revealed vacuolar dystrophy of the liver, necrosis and depletion of lymphocyte in the bursa of Fabricius as well as multiple necroses in the glandular stomach and gut. Even though quantities of 0.70 mg/kg T-2 in the food together with 0.50 mg/kg diacetoxyscirpenol significantly differ from the median lethal dose for chickens reported in literature (4.97 mg/kg), parasitological, virological and histopathological results indicate trichotecenes as the causative agents of this pathological condition.
Sepsis and multiple organ failure continue to be significant problems among trauma, burn, and the critically ill patient population. Thus, a number of laboratories have focused on understanding the role of altered apoptotic cell death in contributing to immune and organ dysfunction seen in sepsis and shock. Immune cells that undergo altered apoptotic changes include neutrophils, macrophages, dendritic cells, as well as various lymphocyte populations. Evidence of epithelial as well as endothelial cell apoptotic changes has also been reported. Although mediators such as steroids, tumor necrosis factor, nitric oxide, C5a, and Fas ligand (FasL) appear to contribute to the apoptotic changes, their effects are tissue- and cell population-selective. As inhibiting Fas-FasL signaling (e.g., gene deficiency, Fas fusion protein, or Fas short interfering RNA administration), caspase inhibition (caspase mimetic peptides), and/or the overexpression of downstream antiapoptotic molecules (e.g., Bcl-2, Akt) improve survival of septic mice, it not only demonstrates the pathological significance of this process but points to novel targets for the treatment of sepsis.
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In 1989, Charles Janeway gave the introduction to the Cold Spring Harbor Symposium on Quantitative Biology, in which he proposed a revolutionary framework for immune recognition whereby pathogen-associated molecular patterns (PAMPs) are recognized by pattern recognition receptors ([
Aims:
Electronegative LDL (LDL(-)) is a plasma LDL subfraction that induces cytokine release in monocytes through toll-like receptor 4 (TLR4) activation. However, the intracellular pathways induced by LDL(-) downstream TLR4 activation are unknown. We aimed to identify the pathways activated by LDL(-) leading to cytokine release in monocytes.
Methods and results:
We determined LDL(-)-induced activation of several intracellular kinases in protein extracts from monocytes using a multikinase ELISA array. LDL(-) induced higher p38 mitogen-activated protein kinase (MAPK) phosphorylation than native LDL. This was corroborated by a specific cell-based assay and it was dependent on TLR4 and phosphoinositide 3-kinase (PI3k)/Akt pathway. P38 MAPK activation was involved in cytokine release promoted by LDL(-). A specific ELISA showed that LDL(-) activated cAMP response-element binding (CREB) in a p38 MAPK dependent manner. P38 MAPK was also involved in the nuclear factor kappa-B (NF-kB) and activating protein-1 (AP-1) activation by LDL(-). We found that NF-kB, AP-1 and CREB inhibitors decreased LDL(-)-induced cytokine release, mainly on MCP1, IL6 and IL10 release, respectively.
Conclusions:
LDL(-) promotes p38 MAPK phosphorylation through TLR4 and PI3k/Akt pathways. Phosphorylation of p38 MAPK is involved in NF-kB, AP-1 and CREB activation, leading to LDL(-)-induced cytokine release in monocytes.
When given intravenously (iv), lipopolysaccharide (LPS) transiently suppresses the structure and function of the bovine corpus luteum (CL). This is associated with increased release of prostaglandin (PG) F2α metabolite (PGFM). The underlying regulatory mechanisms of this process remain, however, obscure. Therefore, the aims of this study were: (1) to investigate the expression of the LPS receptor toll-like receptor (TLR) 4 and TLR2 in the bovine CL during early, mid, and late luteal phases; (2) to further dissect the mechanisms of LPS-mediated suppression of luteal function. As revealed by semi-quantitative qPCR and immunohistochemistry, both receptors were detectable throughout the luteal lifespan. Their mRNA levels increased from the early towards the mid-luteal phase; no further changes were observed thereafter. The TLR4 protein seemed more highly represented than TLR2. The cellular localization of TLRs was in blood vessels; weaker signals were observed in luteal cells. Additionally, cows were treated either with LPS (iv, 0.5 µg/kgBW) or with saline on Day 10 after ovulation. Samples were collected 12 h after treatment, and on Day 10 of the respective subsequent (untreated) cycle. The mRNA expression of several possible regulatory factors was investigated, revealing the suppression of PGF2α receptor (PTGFR), steroidogenic acute regulatory protein (STAR) and 3β-hydroxysteroid dehydrogenase (3βHSD), compared with controls and subsequent cycles. The expression of TLR2 and TLR4, interleukin (IL) 1α and IL1β, and of PGF2α and PGE2 synthases (20αHSD/PGFS and mPTGES, respectively) was increased. The results demonstrate the presence of TLR2 and TLR4 in the bovine CL, and implicate their possible involvement in the deleterious effects of LPS on its function.
Crebanine, an aporphine alkaloid, displays various biological activities such as anticancer and antimicrobial activities. In this study, we further investigated the suppressive effect of crebanine on lipopolysaccharide (LPS)-induced expression of proinflammatory mediators and the molecular mechanisms underlying these activities in RAW 264.7 macrophages. Crebanine inhibited the production of proinflammatory cytokines including interleukin-6 (IL-6) and tumor necrosis factor-alpha in LPS-induced RAW 264.7 cells. Moreover, crebanine suppressed LPS-induced inducible nitric oxide (iNO) and prostaglandin E2 and reduced the expression of iNO synthase and cyclooxygenase-2 in RAW 264.7 cells. Crebanine suppressed LPS-induced phosphorylation of Akt and mitogen-activated protein kinases (MAPKs), including extracellular signaling-regulated kinase 1/2, c-Jun NH2-terminal kinase, and p38 MAPK signaling. In addition, the specific inhibitor of MAPKs and Akt reduced the expression of IL-6 and NO production in LPS-induced macrophages. Furthermore, crebanine inhibited LPS-induced nuclear factor kappa B (NF-κB) activation by reducing the phosphorylation of p65 at serine 536 but not the p65 translocation to the nucleus and inhibitory factor kappa B alpha degradation. Crebanine also suppressed phosphorylation and nucleus translocation of activator protein-1 (AP-1). These observations suggest that the antiinflammatory properties of crebanine may stem from the inhibition of proinflammatory mediators via suppression of the NF-κB, AP-1, MAPKs, and Akt signaling pathways.
The bursa of Fabricius, the key humoral immune organ unique to birds, is critical for B cell differentiation and antibody production. BP8 (AGHTKKAP) is a novel immunomodulatory peptide that regulates B-cell development. Gene microarray was used to investigate the mechanism of BP8 on B cell development. BP8 regulated expressions of 1,570 genes that were involved in retinol metabolism, the Wnt signaling pathway, MAPK pathway, Jak-Stat pathway, Notch signaling pathway, cytokine-cytokine receptor interaction, and Ca(2+) signals. Finally, BP8 triggered ADH7 and RDH10 expression, interacted with retinol binding protein, and regulated retinol uptake in vitro and vivo. These data reveal a bursal-derived multifunctional factor, BP8, as a novel biomaterial which is essential for the development of the immune system and represents an important linker between the B cell development and retinol metabolism. This study elucidates the mechanisms involved in humoral immune system and has implications in treating human diseases.
Infectious bursal disease virus (IBDV) infection destroys the bursa of Fabricius, causing immunosuppression and rendering chickens susceptible to secondary bacterial or viral infections. IBDV large-segment-protein-expressing DNA has been shown to confer complete protection of chickens from infectious bursal disease (IBD). The purpose of the present study was to compare DNA-vaccinated chickens and unvaccinated chickens upon IBDV challenge by transcriptomic analysis of bursa regarding innate immunity, inflammation, immune cell regulation, apoptosis and glucose transport. One-day-old specific-pathogen-free chickens were vaccinated intramuscularly three times at weekly intervals with IBDV large-segment-protein-expressing DNA. Chickens were challenged orally with 8.2 × 102 times the egg infective dose (EID)50 of IBDV strain variant E (VE) one week after the last vaccination. Bursae collected at 0.5, 1, 3, 5, 7, and 10 days post-challenge (dpc) were subjected to real-time RT-PCR quantification of bursal transcripts related to innate immunity, inflammation, immune cell regulation, apoptosis and glucose transport. The expression levels of granzyme K and CD8 in DNA-vaccinated chickens were significantly (p
Marek's disease (MD) is a lymphoproliferative disease of domestic chickens that is caused by a highly cell-associated oncogenic alpha-herpesvirus, Marek's disease virus (MDV). MDV replicates in chicken lymphocytes and establishes a latent infection within CD4+ T cells. MD is characterized by bursal and thymic atrophy and rapid onset of T cell lymphomas that infiltrate lymphoid tissues, visceral organs, and peripheral nerves with severe clinical symptoms that include transient paralysis, anemia, weight loss, and neurologic disorders. The cecal tonsils (CT) are considered the largest lymphoid aggregates of avian gut-associated lymphoid tissue (GALT). Along with Peyer's patches, CT elicits protective immune responses against bacterial and viral pathogens in the intestinal tract of avian species. In this study we investigated the effect of MDV infection on CT structural changes and cytokine gene expression in two MD-susceptible and resistant chicken lines. The histopathologic analysis revealed that MDV causes the loss of germinal follicular centers within the CT of the resistant line while inducing a severe, near-total lymphoid depletion in the susceptible line during cytolytic infection. The lymphoid depletion, however, recovered approximately 2 wk postinfection but the loss of germinal centers persisted during the latent phase of infection in both lines. The atrophy of this important GALT was transient and there were no visible differences between the CT of the infected and control birds of either line by 21 days postinfection. Of the genes tested, IFN-beta and IFN-gamma were up regulated in the CT of both infected lines during lytic infection. The expression levels of both genes were much higher in the susceptible line than in the resistant line. A similar pattern of expression was observed for IL-6, IL-10, IL-13, and iNOS. IL-12 was up regulated in the CT of birds of the susceptible line during all three phases of infection. An over expression of IL-18 was also observed in CT of the susceptible line during lytic and latent phases of infection. IL-8 was the only cytokine expressed at higher levels in the CT of the resistant line during the lytic and reactivation phases of infection. The histopathologic observations and gene expression profiling are further discussed.
Lipopolysaccharide (LPS) has been implicated in mesenchymal stem cell differentiation processes. Wnt5a, one of the "non-canonical" Wnt family members, is important in signaling stem cell differentiation and in the inflammatory responses of immune cells. Here we studied whether LPS can regulate the expression of Wnt5a in human dental pulp stem cells (hDPSCs) and investigated the intracellular signaling pathways activated by LPS.
Wnt5a mRNA and protein expression changes in hDPSCs were investigated by real-time polymerase chain reaction analysis and enzyme-linked immunosorbent assay. In addition, real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and luciferase activity assays were used to determine whether toll-like receptor 4 (TLR4), myeloid differentiating factor 88 (MyD88), nuclear factor kappa B (NF-kB), or the phosphatidylinositol 3-OH kinase (PI3K)/AKT pathways are involved in LPS-induced Wnt5a expression. The activation of PI3K and AKT in hDPSCs was measured by Western blot analysis.
Wnt5a mRNA and protein expression was rapidly increased in response to LPS in a time- and dose-dependent manner. LPS-induced Wnt5a expression was effectively attenuated by administration of a TLR4 neutralizing antibody, MyD88 inhibitory peptide, PI3-kinase inhibitors (LY294002 and wortmannin), an AKT inhibitor, or NF-κB inhibitor (pyrrolidine dithiocarbamate), IκBa phosphorylation inhibitor (Bay 117082), or IκB protease inhibitor (L-1-tosylamido-2-phenylethyl chloromethyl ketone). Treatment of hDPSCs with LPS activated PI3-kinase (p85) and AKT signaling in a time-dependent manner. Moreover, LPS-mediated increases in κB-luciferase activity were diminished by the overexpression of dominant negative mutants of TLR4, MyD88, p85, AKT, and IκBa.
These results demonstrated that LPS-induced Wnt5a expression was mediated through the TLR4/MyD88/PI3-kinase/AKT pathway, which then initiated NF-κB activation in hDPSCs.
Abstract 1. An experiment was conducted to study the effect of yeast (Saccharomyces cerevisiae) cell wall (YCW) supplemented in diets of broiler chickens challenged with Escherichia coli lipopolysaccharide (LPS). 2. One-day-old broiler chicks were randomly distributed into 24 cages (6 replicate cages; 8 birds/cage) and were inoculated with 0 or 1 mg/kg body weight E. coli-LPS (d 4 and 9) and 0 or 500 mg YCW/kg feed, resulting in a 2 × 2 factorial arrangement of treatments. Experimental diets did not include coccidiostats, in-feed antibiotics or enzymes. 3. On d 21, the inoculation of E. coli-LPS reduced weight gain and feed intake and increased feed conversion ratio (FCR) of birds, an effect maintained until 28 d. In contrast, chickens given diets with YCW improved the FCR at both 21 and 28 d of age. 4. E. coli-LPS challenge reduced the relative weight of bursa of Fabricius, except when chickens were given YCW, which resulted in an interaction. Supplementation of broiler diets with YCW exacerbated the cellular immune response as measured by the delayed cutaneous hypersensitivity response test. 5. The results of this study suggested a benefit on feed efficiency when YCW was added to diets fed to broiler chickens challenged with E. coli-LPS. Part of the mode of action of YCW might be related to better maintenance of immune status in response to microbial challenge.
Peroxisome proliferator-activated receptors (PPARs) have been implicated in metabolic diseases, such as obesity, diabetes,
and atherosclerosis, due to their activity in liver and adipose tissue on genes involved in lipid and glucose homeostasis.
Here, we show that the PPARα and PPARγ forms are expressed in differentiated human monocyte-derived macrophages, which participate
in inflammation control and atherosclerotic plaque formation. Whereas PPARα is already present in undifferentiated monocytes,
PPARγ expression is induced upon differentiation into macrophages. Immunocytochemistry analysis demonstrates that PPARα resides
constitutively in the cytoplasm, whereas PPARγ is predominantly nuclear localized. Transient transfection experiments indicate
that PPARα and PPARγ are transcriptionally active after ligand stimulation. Ligand activation of PPARγ, but not of PPARα,
results in apoptosis induction of unactivated differentiated macrophages as measured by the TUNEL assay and the appearance
of the active proteolytic subunits of the cell death protease caspase-3. However, both PPARα and PPARγ ligands induce apoptosis
of macrophages activated with tumor necrosis factor α/interferon γ. Finally, PPARγ inhibits the transcriptional activity of
the NFκB p65/RelA subunit, suggesting that PPAR activators induce macrophage apoptosis by negatively interfering with the
anti-apoptotic NFκB signaling pathway. These data demonstrate a novel function of PPAR in human macrophages with likely
consequences in inflammation and atherosclerosis.
We compared conventional method for specimen (cell cultures, tissue specimens) preparation for scanning electron microscopy and a method without sputtering and critical-point drying. OTO-method (osmium-thiocarbohydrazide-osmium) with sample impregnation with hexamethyldisilazane followed by air drying was used as an alternative method. Excellent preservation of surface ultrastructures and electrical conductivity was proved. The method is easy to use and does not require additional costs for equipment.
Alterations in intestinal motility are one of the features of sepsis induced by lipopolysaccharide (LPS). This study investigated the role of the nuclear transcription factor κB (NF-κB) in the LPS-induced duodenal contractility alterations, generation of reactive oxygen species (ROS) and production of cytokines in rabbit duodenum. Rabbits were treated with saline, LPS, sulfasalazine + LPS, pyrrolidinedithiocarbamate (PDTC) + LPS or RO 106-9920 + LPS. Contractility studies were performed in an organ bath. The formation of products of oxidative damage to proteins (carbonyls) and lipids (malondialdehyde and 4-hydroxyalkenals) was quantified in intestinal tissue and plasma. The protein expression of NF-κB was measured by Western blot. The DNA binding activity of NF-κB was evaluated by transcription factor activity assay. The expression of interleukin-1β, tumour necrosis factor α (TNF-α), interleukin-6, interleukin-10 and interleukin-8 mRNA was determined by RT-PCR. Sulfasalazine, PDTC and RO 106-9920 blocked the inhibitory effect of LPS on contractions induced by ACh in the longitudinal smooth muscle of rabbit duodenum. Sulfasalazine, PDTC and RO 106-9920 reduced the increased levels of malondialdehyde and 4-hydroxyalkenals and the carbonyls induced by LPS in plasma. Lipopolysaccharide induced the activation, translocation to the nucleus and DNA binding of NF-κB. Lipopolysaccharide increased the mRNA expression of interleukin-6 and TNF-α in duodenal tissue, and this effect was partly reversed by PDTC, sulfasalazine and RO 106-9920. In conclusion, NF-κB mediates duodenal contractility disturbances, the generation of ROS and the increase in the expression of interleukin-6 and TNF-α induced by LPS. Sulfasalazine, PDTC and RO 106-9920 may be therapeutic drugs to reduce these effects.
Forty five Hubbard broiler chicks and Forty five local chicks of one day old were reared on litter floor for 35 days. The chicks were divided into six groups A, B and C for broiler chicks, D, E and F for local chicks. The chicks of group A and D were vaccinated with an intermediate vaccine (Bursine®-2) whereas, the chicks of group B and E were vaccinated with an intermediate-plus type of vaccine (Bursine® Plus). Vaccination has been performed at 14<SUP>th</SUP> day. The chicks of group C and F were acted as control. Five chicks were sacrificed by decapitation from the experimental groups at 21<SUP>st</SUP>, 28<SUP>th</SUP> and 35<SUP>th</SUP> day and the bursae were removed, bursa weight (gram) and body weight (gram) were recorded for each individual bird. Significant decrease of bursa weight (p<0.05) was found in group B compared with that of group C at 21<SUP>st</SUP> day. The bursa weights in group D and E of local chicks were significantly differed at (p<0.05) from that of control group (F). The body weights of group D and E of local chicks were significantly decreased from those of group F at (p<0.05). The present study revealed that the more pathogenic intermediate vaccine (intermediate-plus) caused severe bursa of Fabricius injury in vaccinated local chicks. This could be explained by the lower degree of attenuation of this kind of vaccine and may be also related to the lack of maternally-derived antibody in these chicks.
Specific-pathogen-free 10-week-old chickens were inoculated via the air sac with Escherichia coli and showed lymphocytic depletion of bursa of Fabricius and thymus. In experiment I, chickens were necropsied at 12 and 24 hours, 2, 3, and 5 days after inoculation. At 12 hours after inoculation there was lymphocytic depletion in the medulla of lymphoid follicles of the bursa. At 24 hours after inoculation there was lymphocytic depletion also in the cortex of follicles and edema in interfollicular interstitium and follicular medulla. At 2 and 3 days after inoculation there were more marked lymphocytic depletion in medulla and cortex, and fibrosis in interfollicular interstitium. Partial repopulation of follicles with lymphocytes was seen at 5 days after inoculation. In the thymus, lymphocytic depletion occurred in the cortex. At 12 hours after inoculation, lymphocytic necrosis increased in number more than that of control chickens. The width of the cortex and medulla decreased. At 24 hours after inoculation, lymphocytic necrosis increased further. At 2 to 5 days after inoculation, the boundary between the cortex and medulla of lobules was obscure and cellular elements of the cortex and medulla were mingled. In experiment II, chickens were necropsied as in experiment I and also at 8 and 14 days after inoculation. The relative weights of the bursa and thymus reduced rapidly to minimal relative weights at 8 days after inoculation. At 14 days after inoculation, both bursa and thymus had normal relative weights and histological structures. These findings indicate that E. coli infection may induce transient lymphocytic depletion of lymphoid tissues in the chicken.
Mitogen-activated protein (MAP) kinases are proline-directed serine/threonine kinases that are activated by dual phosphorylation on threonine and tyrosine residues in response to a wide array of extracellular stimuli. Three distinct groups of MAP kinases have been identified in mammalian cells [extracellular-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38]. These MAP kinases are mediators of signal transduction from the cell surface to the nucleus. One nuclear target of these MAP kinase signaling pathways is the transcription factor AP-1. MAP kinases regulate AP-1 transcriptional activity by multiple mechanisms. Here we review recent progress towards understanding AP-1 regulation by the ERK, JNK, and p38 MAP kinase signal transduction pathways.
The eukaryotic cell contains a multitude of pathways coupling environmental stimuli to the specific regulation of gene expression. Two early response transcriptional complexes, NF-kappaB and AP-1, appear to respond to environmental stressors by inducing the expression of response specific downstream genes. Both are well-characterized transcriptional regulatory factors that are induced by a wide variety of seemingly unrelated exogenous and endogenous agents and serve important roles in cell growth and differentiation, immunity, inflammation, and other preprogrammed cellular genetic processes. The activities of NF-kappaB and AP-1 are also affected following exposure to chemicals, drugs, or other agents that appear to alter the cellular oxidation/reduction (redox) status. From these observations, it has been suggested that changes in cellular oxidation/reduction status, communicated via a series of cellular redox-sensitive signaling circuitry employing metal- and thiol-containing proteins, serve as common mechanisms linking environmental stressors to adaptive cellular responses. As such, these transcription factors are ideal paradigms to study the mechanism and possible physiological significance of early response genes in the cellular response to changes in cellular redox status. In this article we summarize the evidence suggesting that cellular redox regulates these transcription factors.
Interleukin 8 (IL-8) and vascular endothelial growth factor (VEGF) promote tumor angiogenesis, growth, and metastasis and are coexpressed by human head and neck squamous cell carcinomas (HNSCCs) and a variety of other cancers. The promoters of the IL-8 and VEGF genes contain different recognition sites for transcription factors nuclear factor (NF)-kappaB and activator protein-1 (AP-1), which we showed previously are coactivated in HNSCCs. NF-kappaB and AP-1 may be modulated by the inhibitor kappaB kinase (IKK) and mitogen-activated protein kinase (MAPK) signal pathways, but the contribution of these pathways to expression of IL-8 and VEGF and as potential targets for antiangiogenesis therapy in HNSCC is not known. In this study, we examined the effects of modulation of the MAPK and IKK pathways on expression of IL-8 and VEGF by UM-SCC-9 and UM-SCC-11B cell lines. Interruption of IKK-mediated activation of NF-kappaB by expression of an inhibitor kappaB alpha mutant (IkappaB alphaM) in UM-SCC-9 cells resulted in partial inhibition of expression of IL-8 but not VEGF. Analysis of possible alternative pathways for induction of these genes revealed activation of the MAPK extracellular signal-regulated kinase (ERK1/2) in cell lines UM-SCC-9 and UM-SCC-11B. Basal and tumor necrosis factor-alpha-inducible phosphorylation of ERK1/2 and secretion of IL-8 and VEGF could be specifically inhibited by a MEK inhibitor, U0126. Expression of IL-8 and VEGF in the cell lines was associated with coactivation of both NF-kappaB and AP-1, and U0126 inhibited both NF-kappaB and AP-1 reporter activity in UM-SCC-9 and UM-SCC-11B cells. The ERK pathway appears to contribute to expression of IL-8 and VEGF and transactivation of NF-kappaB as well as AP-1 in HNSCC. Combined inhibition of both MAPK and IKK pathways may be needed for suppression of the signal transduction mechanism(s) regulating VEGF and IL-8 secretion and angiogenesis by human HNSCC.
R. J., LangleyE. L., TsalikJ. C. v., VelkinburghS. W., GlickmanB. J., RiceC., WangB., ChenL., CarinA., SuarezR. P., MohneyD. H., FreemanM., WangJ., YouJ., WulffJ. W., ThompsonM. A., MoseleyS., ReisingerB. T., EdmondsB., GrinnellD. R., NelsonD. L., DinwiddieN. A., MillerC. J., SaundersS. S., SodenA. J., RogersL., GazourianL. E., FredenburghA. F., MassaroR. M., BaronA. M. K., ChoiG. R., CoreyG. S., GinsburgC. B., CairnsR. M., OteroV. G., FowlerE. P., RiversC. W., WoodsS. F., Kingsmore. (2013) An Integrated Clinico-Metabolomic Model Improves Prediction of Death in Sepsis. Science Translational Medicine 5, 195ra95-195ra95
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Toll-like receptors (TLRs) play a crucial role in the recognition of invading pathogens and the activation of subsequent immune responses against them. Individual TLRs recognize distinct pathogen-associated molecular patterns (PAMPs). The TLR family harbors an extracellular leucine-rich repeat (LRR) domain as well as a cytoplasmic domain that is homologous to that of interleukin-1 receptor (IL-1R). Upon stimulation, TLR recruits IL-1R-associated protein kinases via adaptor MyD88, and finally induces activation of nuclear factor-kappaB and mitogen-activated protein kinases. However, the response to TLR ligands varies, indicating the diversity of TLR signaling pathways. Besides MyD88, several novel adaptor molecules have recently been identified. Differential utilization of these adaptor molecules may provide the specificity in the TLR signaling. Characterization of each TLR signaling pathway will reveal the molecular mechanism of self-tolerance as well as cross-tolerance in response to a variety of PAMPs.
Signals from the IL-1 receptor (IL-1R)/Toll-like receptor (TLR) family and TNF receptor (TNFR) superfamily are critical for regulating the function of antigen-presenting cells such as dendritic cells (DCs). It has been revealed that TNF receptor-associated factor 6 (TRAF6), a signaling adapter molecule common to the IL-1R/TLR family and TNFR superfamily, is important not only for DC maturation, cytokine production, and T cell stimulatory capacity of DCs in response to TLR ligands (e.g. lipopolysaccharide) or CD40 ligand, but also for the homeostasis of splenic DC subsets.
Marek's disease (MD) is a highly contagious lymphoproliferative disease of poultry caused by the oncogenic herpesvirus designated Marek's disease virus (MDV). MD has a worldwide distribution and is thought to cause an annual loss over 1 bn US dollars to the poultry industry. Originally described as a paralytic disease, today MD is mostly manifested as an acute disease with tumours in multiple visceral organs. MD is controlled essentially by the widespread use of live vaccines administered either in ovo into 18-day-old embryos or into chicks immediately after they hatch. In spite of the success of the vaccines in reducing the losses from the disease in the last 30 years, MDV strains have shown continuous evolution in virulence acquiring the ability to overcome the immune responses induced by the vaccines. During this period, different generations of MD vaccines have been introduced to protect birds from the increasingly virulent MDV strains. However, the virus has countered each new vaccine with ever more virulent strains. This continuous race between the virus and the host is making the control of this poultry health problem a major challenge for the future.
Salmonella species cause substantial morbidity, mortality and burden of disease globally. Infections with Salmonella species cause multiple clinical syndromes. Central to the pathophysiology of all human salmonelloses is the induction of a strong host innate immune/inflammatory response. Whether this ultimately reflects an adaptive advantage to the host or pathogen is not clear. However, it is evident that both the host and pathogen have evolved mechanisms of triggering host responses that are detrimental to the other. In this review, we explore some of the host and pathogenic mechanisms mobilized in the two predominant clinical syndromes associated with infection with Salmonella enterica species: enterocolitis and typhoid.
KEGG is a database resource (http:// www. genome. jp/ kegg/ ) that provides all knowledge about genomes and their relationships to biological systems such as cells and whole organisms as well as their interactions with the environment. KEGG is categorized in terms of building blocks in the genomic space, known as KEGG GENES, the chemical space, KEGG LIGAND, as well as wiring diagrams of interaction and reaction networks, known as KEGG PATHWAY. A fourth database called KEGG BRITE was also recently incorporated to provide computerized annotations and pathway reconstruction based on the current KEGG knowledgebase. KEGG BRITE contains KEGG Orthology (KO), a classification of ortholog and paralog groups based on highly confident sequence similarity scores, and the reaction classification system for biochemical reaction classification, along with other classifications for compounds and drugs. BRITE is also the basis for the KEGG Automatic Annotation Server (KAAS), which automatically annotates a given set of genes and correspondingly generates pathway maps. This chapter introduces KEGG and its various tools for genomic analyses, focusing on the usage of the KEGG GENES, PATHWAY, and BRITE resources and the KAAS tool (see
Note 1)
Transcriptome analysis indicated that Salmonella lipopolysaccharide-induced thymocyte death and thymic atrophy were related to TLR4FOS/JUN pathway in chicks
- H Huang
- A Liu
- H Wu
- A R Ansari
- J Wang
- X Huang
- X Zhao
- K Peng
- J Zhong
- H Liu
Huang H, Liu A, Wu H, Ansari AR, Wang J, Huang X,
Zhao X, Peng K, Zhong J, Liu H. Transcriptome analysis
indicated that Salmonella lipopolysaccharide-induced
thymocyte death and thymic atrophy were related to TLR4FOS/JUN pathway in chicks. BMC Genomics. 2016; 17:
322. doi: 10.1186/s12864-016-2674-6.