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ABSTRACT: The mechanisms associated with the cellular internalization of nanomedicines must be carefully considered when designing drug- and vaccine-delivery systems. The cellular fate and effects of nanomedicines depend to a large extent on the cell uptake routes. A self-assembled mannan nanogel is developed as a vaccination platform for antigen and adjuvant delivery. The mannan nanogel uptake by murine bone-marrow-derived macrophages is found to be time-, concentration-, and energy-dependent, involving mannose-receptor-mediated phagocytosis and clathrin-mediated endocytosis. The nanogel is also visualized in the cytosol suggesting endolysosomal escape. These results indicate that mannan nanogel is a promising versatile carrier for intracellular delivery of vaccines or therapeutic agents.
Macromolecular Bioscience 07/2012; 12(9):1172-80. · 3.89 Impact Factor
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ABSTRACT: Polymeric nanogels find a relevant field of application in the formulation of a new generation of therapeutic and preventive vaccines, aiming at the fine-tuned modulation of the immune response. Intrinsic properties of polymeric nanogels, such as material chemistry, size and shape, surface charge, and hydrophobicity or hydrophilicity, may be determining factors in shaping the induced immune response. These materials can thus work as synthetic adjuvants, which can also be conjugated with immunostimulants. Polymeric nanogels protect vaccine antigens from degradation in vivo and, surface-conjugated with antibodies or specific ligands, could increase active targeting specificity. This review covers the recent published data concerning the modulation of innate and adaptive immune responses by engineered polymeric nanogels and their potential application as delivery systems in vaccination.
Nanomedicine: nanotechnology, biology, and medicine 07/2012; · 5.44 Impact Factor
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ABSTRACT: Amphiphilic mannan, produced by the Michael addition of hydrophobic 1-hexadecanethiol to vinyl methacrylated mannan, self-assembles in aqueous medium through hydrophobic interactions among alkyl chains. Resultant nanogel is stable, spherical, polydisperse, with 50-140 nm mean hydrodynamic diameter depending on the polymer degree of substitution, and nearly neutral negative surface charge. No cytotoxicity of mannan nanogel is detected up to about 0.4 mg/mL in mouse embryo fibroblast cell line 3T3 and mouse bone marrow-derived macrophages (BMDM) using cell proliferation, lactate dehydrogenase and Live/Dead assays. Comet assay, under the tested conditions, reveals no DNA damage in fibroblasts but possible in BMDM. BMDM internalize the mannan nanogel, which is observed in vesicles in the cytoplasm by confocal laser scanning microscopy. Confocal colocalization image analysis denotes that the entrance and exit of nanogel and FM 4-64 might occur by the same processes--endocytosis and exocytosis--in BMDM. Physicochemical characteristics, in vitro cytocompatibility and uptake of self-assembled mannan nanogel by mouse BMDM are great signals of the potential applicability of this nanosystem for macrophages targeted delivery of vaccines or drugs, acting as potential nanomedicines, always with the key goal of preventing and/or treating diseases.
Journal of Biomedical Nanotechnology 06/2012; 8(3):473-81. · 4.22 Impact Factor
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ABSTRACT: Group B Streptococcus (GBS) is the leading cause of neonatal pneumonia, septicemia, and meningitis. We have previously shown that in adult mice GBS glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an extracellular virulence factor that induces production of the immunosuppressive cytokine interleukin-10 (IL-10) by the host early upon bacterial infection. Here, we investigate whether immunity to neonatal GBS infection could be achieved through maternal vaccination against bacterial GAPDH. Female BALB/c mice were immunized with rGAPDH and the progeny was infected with a lethal inoculum of GBS strains. Neonatal mice born from mothers immunized with rGAPDH were protected against infection with GBS strains, including the ST-17 highly virulent clone. A similar protective effect was observed in newborns passively immunized with anti-rGAPDH IgG antibodies, or F(ab')(2) fragments, indicating that protection achieved with rGAPDH vaccination is independent of opsonophagocytic killing of bacteria. Protection against lethal GBS infection through rGAPDH maternal vaccination was due to neutralization of IL-10 production soon after infection. Consequently, IL-10 deficient (IL-10(-/-)) mice pups were as resistant to GBS infection as pups born from vaccinated mothers. We observed that protection was correlated with increased neutrophil trafficking to infected organs. Thus, anti-rGAPDH or anti-IL-10R treatment of mice pups before GBS infection resulted in increased neutrophil numbers and lower bacterial load in infected organs, as compared to newborn mice treated with the respective control antibodies. We showed that mothers immunized with rGAPDH produce neutralizing antibodies that are sufficient to decrease IL-10 production and induce neutrophil recruitment into infected tissues in newborn mice. These results uncover a novel mechanism for GBS virulence in a neonatal host that could be neutralized by vaccination or immunotherapy. As GBS GAPDH is a structurally conserved enzyme that is metabolically essential for bacterial growth in media containing glucose as the sole carbon source (i.e., the blood), this protein constitutes a powerful candidate for the development of a human vaccine against this pathogen.
PLoS Pathogens 11/2011; 7(11):e1002363. · 9.13 Impact Factor
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ABSTRACT: Staphylococcus epidermidis biofilms with different proportions of viable but nonculturable bacteria were used to show that SYBR green (SYBR) may be used as a probe to evaluate the bacterial physiological state using flow cytometry. Biofilms grown in excess glucose presented significantly higher proportions of dormant bacteria than biofilms grown in excess glucose with buffered pH conditions or with exponential-phase planktonic cultures. Bacteria obtained from biofilms with high or low proportions of viable but nonculturable cells were further cultured in broth medium and stained with SYBR at different time points. An association between bacterial growth and SYBR staining intensity was observed. In addition, bacteria presenting higher SYBR fluorescence intensity also stained more intensely with cyanoditolyl tetrazolium chloride, used as a probe to evaluate cellular metabolism. Accordingly, planktonic bacteria treated with rifampicin, an inhibitor of bacterial RNA transcription, presented lower SYBR and cyanoditolyl tetrazolium chloride staining intensity than nontreated bacteria. Overall, our results indicate that SYBR, in addition to being used as a component of LIVE/DEAD stain, may also be used as a probe to evaluate the physiological state of S. epidermidis cells.
Canadian Journal of Microbiology 09/2011; 57(10):850-6. · 1.36 Impact Factor
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ABSTRACT: Bracken (Pteridium aquilinum) has long been known to cause cancer in farm and laboratory animals. Ptaquiloside, a norsesquiterpene glycoside found in bracken, is considered its main carcinogenic toxin and is capable of inducing tumours in a variety of organ systems, but especially in the urinary bladder, depending on the animal species, the administration route employed and the duration of exposure. In the present study, 12 male CD-1 mice were intraperitoneally administered with 0.5 mg ptaquiloside weekly for 15 weeks, followed by 15 weeks without any treatment. Twelve animals used as controls were administered the vehicle solution (phosphate buffered saline). Two exposed animals died during the experimental work. On necropsy, blood and tissue samples (brain, eyes, thymus, heart, lungs, liver, digestive system, spleen, bladder, kidney, adrenal gland, urinary bladder, sexual accessory glands, testes, muscle, skin and femur) were collected for histological analysis. Leukograms were prepared from blood smears and total WBC counts obtained with a Neubauer chamber. Flow cytometry was used to assess blood T-(CD3(+)) and B-(CD19(+))-lymphocytes, medullary granulocytic (CD11b(+)/Ly-6G(-), CD11b(+)/Ly-6G(+)) and lymphocytic (CD19(+)/IgM(-), CD19+/IgM(+)) populations and thymic lymphoid (CD4(+), CD8(+), CD4(+)/CD8(+)) populations. Lymphoproliferative lesions were analysed immunohistochemically using antibodies against CD45R and CD3. All of the 10 surviving mice developed a lymphoproliferative malignancy. Lymphoproliferative disease was characterized by multifocal B-(CD45(+)/CD3(-))-lymphocytic renal (10/10 animals) and hepatic (2/10 animals) invasion, splenic white pulp hyperplasia (10/10) together with a significant increase in circulating B-(CD19(+))-lymphocytes and the appearance of circulating dysplastic lymphoid cells. Eight out of 10 ptaquiloside-exposed animals developed urothelial dysplasia (six low-grade dysplasia and two high-grade dysplasia). No lesions were detected in control mice. These results show that ptaquiloside is capable of inducing malignant transformation in mice and provide an in-depth characterisation of lymphoproliferative lesions. Furthermore, the urinary bladder is shown to be a target organ for this toxin in mice as well as in other animal species.
Toxicon 09/2011; 58(6-7):543-9. · 2.51 Impact Factor
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ABSTRACT: Staphylococcus epidermidis is an opportunistic pathogen and, due to its ability to establish biofilms, is a leading causative agent of indwelling medical device-associated infection. The presence of high amounts of dormant bacteria is a hallmark of biofilms, making them more tolerant to antimicrobials and to the host immune response. We observed that S. epidermidis biofilms grown in excess glucose accumulated high amounts of viable but non-culturable (VBNC) bacteria, as assessed by their low ratio of culturable bacteria over the number of viable bacteria. This effect, which was a consequence of the accumulation of acidic compounds due to glucose metabolism, was counteracted by high extracellular levels of calcium and magnesium added to the culture medium allowing modulation of the proportions of VBNC bacteria within S. epidermidis biofilms. Using bacterial inocula obtained from biofilms with high and low proportions of VBNC bacteria, their stimulatory effect on murine macrophages was evaluated in vitro and in vivo. The inoculum enriched in VBNC bacteria induced in vitro a lower production of tumour necrosis factor alpha, interleukin-1 and interleukin-6 by bone-marrow-derived murine macrophages and, in vivo, a lower stimulatory effect on peritoneal macrophages, assessed by increased surface expression of Gr1 and major histocompatibility complex class II molecules. Overall, these results show that environmental conditions, such as pH and extracellular levels of calcium and magnesium, can induce dormancy in S. epidermidis biofilms. Moreover, they show that bacterial suspensions enriched in dormant cells are less inflammatory, suggesting that dormancy can contribute to the immune evasion of biofilms.
Journal of Medical Microbiology 07/2011; 60(Pt 12):1717-24. · 2.50 Impact Factor
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ABSTRACT: PNAG is a major component of Staphylococcus epidermidis biofilms involved in intercellular adhesion as well as in the interaction of the biofilm with components of the host immune response. Synthesis of PNAG has been found to be regulated by several environmental factors. In the present study, the effect of glucose metabolism-dependent culture medium acidification in PNAG accumulation was evaluated. Established S. epidermidis biofilms were allowed to grow in excess glucose with or without maintained pH conditions. PNAG accumulation in these biofilms was determined by flow cytometry and fluorescence microscopy using wheat germ agglutinin as a fluorescent probe. Biofilms grown in maintained pH conditions presented significantly higher amounts of this polymer as well as higher icaA expression than biofilms grown in acidic pH conditions. Moreover, PNAG accumulation in biofilms grown in non-maintained pH conditions occurred in association with cell death. Overall, we show that glucose metabolism by decreasing the culture pH affects biofilm physiology in respect to PNAG production and cell death. The reported in vitro modulation of PNAG accumulation within S. epidermidis biofilms further highlights the role of environment on determining the biofilm physiological state.
Microbiology and Immunology 07/2011; 55(10):673-82. · 1.30 Impact Factor
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ABSTRACT: The bacterial cellulose (BC) secreted by Gluconacetobacter xylinus is a network of pure cellulose nanofibres which has high crystallinity, wettability and mechanical strength. These characteristics make BC an excellent material for tissue-engineering constructs, noteworthy for artificial vascular grafts. In this work, the in vivo biocompatibility of BC membranes produced by two G. xylinus strains was analyzed through histological analysis of long-term subcutaneous implants in the mice. The BC implants caused a mild and benign inflammatory reaction that decreased along time and did not elicit a foreign body reaction. A tendency to calcify over time, which may be related to the porosity of the BC implants, was observed, especially among the less porous BC-1 implants. In addition, the potential toxicity of BC nanofibres - obtained by chemical-mechanical treatment of BC membranes - subcutaneously implanted in mice was analysed through bone marrow flow cytometryand histological analyses. At 2 and 4 months post-implantation, the nanofibres implants were found to accumulate intracellularly, in subcutaneous foamy macrophages aggregates. Moreover, no differences were observed between the controls and implanted animals in thymocyte populations and in B lymphocyte precursors and myeloid cells in the bone marrow.
Journal of Biomaterials Science Polymer Edition 06/2011; · 1.69 Impact Factor
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ABSTRACT: Antimicrobial peptides (AMPs) are part of the innate immune system and are generally defined as cationic, amphipathic peptides, with less than 50 amino acids, including multiple arginine and lysine residues. The human cathelicidin antimicrobial peptide LL37 can be found at different concentrations in many different cells, tissues and body fluids and has a broad spectrum of antimicrobial and immunomodulatory activities. The healing of wound is a complex process that involves different steps: hemostasis, inflammation, remodeling/granulation tissue formation and re-epithelialization. Inflammation and angiogenesis are two fundamental physiological conditions implicated in this process. We have recently developed a new method for the expression and purification of recombinant LL37. In this work, we show that the recombinant peptide P-LL37 with a N-terminus proline preserves its immunophysiological properties in vitro and in vivo. P-LL37 neutralized the activation of macrophages by lipopolysaccharide (LPS). Besides, the peptide induced proliferation, migration and tubule-like structures formation by endothelial cells. Wound healing experiments were performed in dexamethasone-treated mice to study the effect of LL37 on angiogenesis and wound regeneration. The topical application of synthetic and recombinant LL37 increased vascularization and re-epithelialization. Taken together, these results clearly demonstrate that LL37 may have a key role in wound regeneration through vascularization.
Peptides 06/2011; 32(7):1469-76. · 2.43 Impact Factor
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ABSTRACT: Interleukin-10 (IL-10) is an anti-inflammatory cytokine, which active form is a non-covalent homodimer. Given the potential of IL-10 for application in various medical conditions, it is essential to develop systems for its effective delivery. In previous work, it has been shown that a dextrin nanogel effectively incorporated and stabilized rIL-10, enabling its release over time. In this work, the delivery system based on dextrin nanogels was further analyzed. The biocompatibility of the nanogel was comprehensively analyzed, through cytotoxicity (lactate dehydrogenase (LDH) release, MTS, Live, and Dead) and genotoxicity (comet) assays. The release profile of rIL-10 and its biological activity were evaluated in vivo, using C57BL/6 mice. Although able to maintain a stable concentration of IL-10 for at least 4 h in mice serum, the amount of protein released was rather low. Despite this, the amount of rIL-10 released from the complex was biologically active inhibiting TNF-α production, in vivo, by LPS-challenged mice. In spite of the significant stabilization achieved using the nanogel, rIL-10 still denatures rather quickly. An additional effort is thus necessary to develop an effective delivery system for this cytokine, able to release active protein over longer periods of time. Nevertheless, the good biocompatibility, the protein stabilization effect and the ability to perform as a carrier with controlled release suggest that self-assembled dextrin nanogels may be useful protein delivery systems.
Biotechnology and Bioengineering 03/2011; 108(8):1977-86. · 3.95 Impact Factor
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ABSTRACT: The aim of this study was to determine the effect of exogenous farnesol in yeast-to-hyphae morphogenesis, and Saps (2, 4, 5 and 6) mRNA expressions by a Candida strain that does not produce endogenous farnesol. C. albicans was cultured in the absence and presence of farnesol at various concentrations (10, 100, and 300 µM), in proteinase induction medium, and then used to determine yeast-to- hyphae changes, Candida ultrastructure and to determine Saps 2, 4, 5 and 6 expressions using q-TR-PCR and ELISA (for Sap2). Data demonstrated that farnesol greatly reduced the yeast-to-hyphae morphogenesis of a Candida strain that does not produce endogenous farnesol. Farnesol induced several ultrastructural alterations, including changes in the cell-wall shape, a visible disconnection between the cell wall and cytoplasm with an electron-lucent zone between them, and the presence of electron-dense vacuoles. Tested on gene expressions, farnesol was able to significantly (p < 0.01) decrease Sap2 secretion and mRNA expression. Farnesol downregulated also Sap4-6 mRNA expression. These results demonstrated for the first time that farnesol modules Candida morphogenesis through a downregulation of Saps 2, 4, 5 and 6 expressions. Overall these data point to the potential use of farnesol as an antifungal molecule.
The Open Microbiology Journal 01/2011; 5:119-26.
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ABSTRACT: Interleukin-10 (IL-10) is an anti-inflammatory cytokine, which active form is a non-covalent homodimer with two intramolecular disulphide bonds essential for its biological activity. A mutated form of murine IL-10 was successfully expressed in E. coli, recovered and purified from inclusion bodies. Its ability to reduce tumor necrosis factor α synthesis and down-regulate class II major histocompatibility complex molecules expression on endotoxin-stimulated bone marrow-derived macrophages was confirmed, and shown to be similar to that of a commercially available IL-10. Given the potential of IL-10 for application in various medical conditions, it is essential to develop systems that can effectively deliver the protein. In this work it is shown that a dextrin nanogel effectively incorporate IL-10, stabilize, and enable the slow release of biologically active IL-10 over time. Altogether, these results demonstrate the suitability of dextrin nanogel to be used as a system for the controlled release of IL-10.
International journal of pharmaceutics 11/2010; 400(1-2):234-42. · 2.96 Impact Factor
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Alexandra Correia,
Ulrich Lermann,
Luzia Teixeira,
Filipe Cerca,
Sofia Botelho,
Rui M Gil da Costa,
Paula Sampaio,
Fátima Gärtner,
Joachim Morschhäuser, Manuel Vilanova,
Célia Pais
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ABSTRACT: Candida albicans secreted aspartyl proteinases (Saps) are considered virulence-associated factors. Several members of the Sap family were claimed to play a significant role in the progression of candidiasis established by the hematogenous route. This assumption was based on the observed attenuated virulence of sap-null mutant strains. However, the exclusive contribution of SAP genes to their attenuated phenotype was not unequivocally confirmed, as the Ura status of these mutant strains could also have contributed to the attenuation. In this study, we have reassessed the importance of SAP1 to SAP6 in a murine model of hematogenously disseminated candidiasis using sap-null mutant strains not affected in their URA3 gene expression and compared their virulence phenotypes with those of Ura-blaster sap mutants. The median survival time of BALB/c mice intravenously infected with a mutant strain lacking SAP1 to SAP3 was equivalent to that of mice infected with wild-type strain SC5314, while those infected with mutant strains lacking SAP5 showed slightly extended survival times. Nevertheless, no differences could be observed between the wild type and a Δsap456 mutant in their abilities to invade mouse kidneys. Likewise, a deficiency in SAP4 to SAP6 had no noticeable impact on the immune response elicited in the spleens and kidneys of C. albicans-infected mice. These results contrast with the behavior of equivalent Ura-blaster mutants, which presented a significant reduction in virulence. Our results suggest that Sap1 to Sap6 do not play a significant role in C. albicans virulence in a murine model of hematogenously disseminated candidiasis and that, in this model, Sap1 to Sap3 are not necessary for successful C. albicans infection.
Infection and immunity 11/2010; 78(11):4839-49. · 4.21 Impact Factor
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ABSTRACT: Galectin-3 is a glycan-binding protein that mediates cell-cell and/or cell-extracellular matrix (ECM) interactions. Although galectin-3 is implicated in the progression of various types of cancers, the mechanisms by which galectin-3 enhances metastasis remain unclear. In order to elucidate the role of galectin-3 in the complex multistage process of cancer metastasis, we examined galectin-3 and galectin-3-binding site expression in a series of 82 spontaneous canine mammary tumors (CMT) and two CMT cell lines. Benign CMT tumors exhibited strong nuclear/cytoplasmic galectin-3 immunostaining, whereas malignant CMT tumors and metastases exhibited dramatically decreased galectin-3 expression with the majority of the immunostaining confined to the cytoplasm. Interestingly, intravascular tumor cells overexpressed galectin-3 regardless of their location. CMT-U27 xenografts displayed the same pattern of galectin-3 expression found in spontaneous malignant CMT. In parallel with the downregulation of galectin-3, malignant CMT displayed an overall loss of galectin-3-binding sites in the ECM and focal expression of galectin-3-binding sites mainly detected in intravascular tumor cells and endothelium. Furthermore, loss of galectin-3-binding sites was correlated with the downregulation of GLT25D1, a β (1-O) galactosyltransferase that modifies collagen, and upregulation of stromal galectin-1. Finally, GLT25D1 mRNA expression was strikingly downregulated in malignant CMT-U27 compared with the benign cell line, and its expression was further decreased in a galectin-3 knockdown CMT-U27 cell line. We therefore hypothesized that the loss of galectin-3-binding sites in the ECM in conjunction with the overexpression of galectin-3 in specific tumor cell subpopulations are crucial events for the development of mammary tumor metastases.
Glycobiology 11/2010; 20(11):1341-52. · 3.58 Impact Factor
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ABSTRACT: Neospora caninum is a coccidian parasite causative of clinical infections in a wide range of animal hosts. The maturation and activation of splenic conventional dendritic cells (cDCs) and plasmacytoid dendritic cells (pDCs) were studied here in BALB/c mice challenged intraperitoneal with N. caninum tachyzoites. The number of cDCs was found to decrease in the spleen of the infected mice 12 h and 2 days after the parasitic challenge, whereas at day 5 after infection it was significantly above that of mock-infected controls. In contrast, the number of splenic pDCs did not change significantly on infection. In the infected mice, both cell subtypes displayed an activated phenotype with upregulation of costimulatory and MHC class II molecules. This stimulatory effect was more marked at the earliest assessed time point after infection, 12 h, when a clear increase in the frequency of cDCs (CD8α+ and CD8α−) and pDCs producing interleukin-12 (IL-12) was also observed. N. caninum tachyzoites could be observed by confocal microscopy associated with sorted DCs. Overall, these results present the first evidence that both cDCs and pDCs mediate in vivo the innate immune response to N. caninum infection through the production of IL-12, a key cytokine for host resistance to neosporosis.Keywords: conventional dendritic cells, plasmacytoid dendritic cells, IL-12, CD8α, Neospora caninum
Immunology and Cell Biology 09/2009; 88(1):79-86. · 3.66 Impact Factor
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ABSTRACT: Neospora caninum is a coccidian parasite causative of clinical infections in a wide range of animal hosts. The maturation and activation of splenic conventional dendritic cells (cDCs) and plasmacytoid dendritic cells (pDCs) were studied here in BALB/c mice challenged intraperitoneal with N. caninum tachyzoites. The number of cDCs was found to decrease in the spleen of the infected mice 12 h and 2 days after the parasitic challenge, whereas at day 5 after infection it was significantly above that of mock-infected controls. In contrast, the number of splenic pDCs did not change significantly on infection. In the infected mice, both cell subtypes displayed an activated phenotype with upregulation of costimulatory and MHC class II molecules. This stimulatory effect was more marked at the earliest assessed time point after infection, 12 h, when a clear increase in the frequency of cDCs (CD8alpha(+) and CD8alpha(-)) and pDCs producing interleukin-12 (IL-12) was also observed. N. caninum tachyzoites could be observed by confocal microscopy associated with sorted DCs. Overall, these results present the first evidence that both cDCs and pDCs mediate in vivo the innate immune response to N. caninum infection through the production of IL-12, a key cytokine for host resistance to neosporosis.
Immunology and Cell Biology 09/2009; 88(1):79-86. · 3.66 Impact Factor
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ABSTRACT: Coffee infusion mannans are acetylated polysaccharides containing single Galp and Araf residues as side chains of a beta-(1 --> 4)-Manp backbone. These mannans are structurally similar to the bioactive acetylated mannans from Aloe vera (AV). In this study, acetylated mannans were obtained from two coffee infusions prepared from light and dark roasted beans. These samples were tested for their immunostimulatory activity and compared with an extract of AV mannan and with locust bean gum (LBG) galactomannans. The coffee samples, as well as the AV extract, stimulated murine B- and T-lymphocytes, as evaluated by the in vitro expression of the surface lymphocyte activation marker CD69, more marked on B- than on T-lymphocytes. In coffee samples, contrarily to the AV, no proliferative effect was noticed. LBG sample did not show any immunostimulatory activity. Because the material that remains in the residue of the hot water extraction was still very rich in mannans, a sequential extraction was performed and a main fraction was recovered with a 4 M NaOH solution. Because this material was insoluble in water, a partial acetylation was performed. These polysaccharides also showed immunostimulatory activity, opening the possibility of exploitation of coffee infusion and coffee residue as sources of bioactive polysaccharides.
Molecular Nutrition & Food Research 08/2009; 53(8):1036-43. · 4.30 Impact Factor
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ABSTRACT: Evaluation of: Koh AY, Köhler JR, Coggshall KT, Van Rooijen N, Pier GB. Mucosal damage and neutropenia are required for Candida albicans dissemination. PLoS Pathog. 4(2), e35 (2008). Candida spp. rank among the leading causative agents of nosocomial infections. The increasing number of patients at risk of invasive candidiasis makes a rise in the incidence of this fungal infection expected. Disruption of GI tract integrity and ablation of immune cell populations, such as those resulting from cancer chemotherapy, are recognized as key factors leading to fungal dissemination. However, the individual role of these immune barriers in preventing Candida host colonization and invasion are yet to be fully understood. This article evaluates recently published results on a new murine model of systemic candidiasis originating in the GI tract that might prove a valuable setting for the accurate study of host immune mechanisms, fungal virulence factors and novel therapeutic approaches.
Expert Review of Anticancer Therapy 07/2008; 6(4):441-445. · 3.28 Impact Factor
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ABSTRACT: Cellulose Binding Domains (CBD) were conjugated with fluorescein isothiocyanate (FITC). The surface concentration of the Binding Domains adsorbed on cellulose fibres was determined by fluorescence image analysis.
For a CBD-FITC concentration of 60 mg/L, a coating fraction of 78% and 110% was estimated for Portucel and Whatman fibres, respectively. For a saturating CBD concentration, using Whatman CF11 fibres, a surface concentration of 25.2 x 10-13 mol/mm2 was estimated, the equivalent to 4 protein monolayers. This result does not imply the existence of several adsorbed protein layers.
It was verified that CBDs were able to penetrate the fibres, according to confocal microscopy and TEM-immunolabelling analysis. The surface concentration of adsorbed CBDs was greater on amorphous fibres (phosphoric acid swollen) than on more crystalline ones (Whatman CF11 and Sigmacell 20).
BMC Biotechnology 02/2008; 8:1. · 2.35 Impact Factor
