[Show abstract][Hide abstract] ABSTRACT: Glycogen expressed by the lower genital tract epithelium is believed to support Lactobacillus growth in vivo, although most genital isolates of Lactobacillus are not able to use glycogen as an energy source in vitro. We recently reported that α-amylase is present in the genital fluid of women and that it breaks down glycogen into small carbohydrates that support growth of lactobacilli. Since the pH of the lower genital tract can be very low, we determined how low pH affects glycogen processing by α-amylase. α-amylase in saliva degraded glycogen similarly at pH 6 and 7, but activity was reduced by 52% at pH 4. The glycogen degrading activity in nine genital samples from seven women showed a similar profile with an average reduction of more than 50% at pH 4. However, two samples collected from one woman at different times had a strikingly different pH profile with increased glycogen degradation at pH 4, 5 and 6 compared to pH 7. This second pH profile did not correlate with levels of human α-acid glucosidase or human intestinal maltase glucoamylase. High-performance anion-exchange chromatography showed that mostly maltose was produced from glycogen by samples with the second pH profile in contrast to genital α-amylase that yielded maltose, maltotriose and maltotetraose. These studies show that at low pH, α-amylase activity is reduced to low but detectable levels, which we speculate helps maintain Lactobacillus growth at a limited but sustained rate. Additionally, some women have a genital enzyme distinct from α-amylase with higher activity at low pH. Further studies are needed to determine the identity and distribution of this second enzyme, and whether its presence influences the makeup of genital microbiota.
PLoS ONE 07/2015; 10(7):e0132646. DOI:10.1371/journal.pone.0132646 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Trichomonas vaginalis infection is associated with an increased risk of HIV infection in exposed-seronegative women (ESN) despite their unique immune quiescent profile. It is important to understand possible mechanisms, such as recruitment of activated T cells, by which T. vaginalis could facilitate HIV infection in this population.
We conducted a cross-sectional study exploring the relationships between T. vaginalis infection, inflammatory markers and T cell activation in the cervix of ESN. During scheduled study visits, participants completed a behavioral questionnaire and physical exam, including sexually transmitted infection (STI) screening and collection of endocervical sponge and cytobrush specimens. T cell and monocyte phenotypes were measured in cervical cytobrush specimens using multi-parameter flow cytometry. Cervical sponge specimens were used to measure cytokines (IL-6, IL-8,IL-10, IP-10, RANTES) using Luminex immunoassays and the immune activation marker soluble TNF receptor 1 using ELISA.
Specimens of 65 women were tested. Twenty-one of these women were infected with T. vaginalis. T. vaginalis infection was associated with significantly increased concentrations of IL-8 (1275pg/ml vs. 566pg/ml, p=.02) and sTNFr1 (430 pg/ml vs. 264 pg/ml, p=.005). However, T. vaginalis infection was not associated with increased percent expression of CCR5+ T cells nor increased CD38 and HLADR activation compared to uninfected women. It was also not associated with increased expression of CCR5+ monocytes.
Among ESN T. vaginalis infection is associated with increased levels of genital pro-inflammatory/immune activation markers IL-8 and TNFr1, but was not associated with an increased percentage of activated endocervical T cells along the CD38 and HLADR pathways. Thus, while T.vaginalis infection may result in some reversal of the immune quiescent profile of ESN, enhanced recruitment of activated CD38 and HLADR expressing CD4+ cells into the endocervix may not be part of the mechanism by which Trichomonas infection alters HIV susceptibility in this unique subset of women.
PLoS ONE 06/2015; 10(6):e0130146. DOI:10.1371/journal.pone.0130146 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: HIV-1-associated disruption of intestinal homeostasis is a major factor contributing to chronic immune activation and inflammation. Dendritic cells (DCs) are crucial in maintaining intestinal homeostasis, but the impact of HIV-1 infection on intestinal DC number and function has not been extensively studied. We compared the frequency and activation/maturation status of colonic myeloid DC (mDC) subsets (CD1c(+) and CD1c(neg)) and plasmacytoid DCs in untreated HIV-1-infected subjects with uninfected controls. Colonic mDCs in HIV-1-infected subjects had increased CD40 but decreased CD83 expression, and CD40 expression on CD1c(+) mDCs positively correlated with mucosal HIV-1 viral load, with mucosal and systemic cytokine production, and with frequencies of activated colon and blood T cells. Percentage of CD83(+)CD1c(+) mDCs negatively correlated with frequencies of interferon-γ-producing colon CD4(+) and CD8(+) T cells. CD40 expression on CD1c(+) mDCs positively associated with abundance of high prevalence mucosal Prevotella copri and Prevotella stercorea but negatively associated with a number of low prevalence mucosal species, including Rumminococcus bromii. CD1c(+) mDC cytokine production was greater in response to in vitro stimulation with Prevotella species relative to R. bromii. These findings suggest that, during HIV infection, colonic mDCs become activated upon exposure to mucosal pathobiont bacteria leading to mucosal and systemic immune activation.Mucosal Immunology advance online publication, 29 April 2015; doi:10.1038/mi.2015.33.
[Show abstract][Hide abstract] ABSTRACT: Background. Individuals infected with human immunodeficiency virus (HIV) live longer as a result of effective treatment, but long-term consequences of infection, treatment, and immunological dysfunction are poorly understood. Methods. We prospectively examined 1011 women (74% HIV-infected) in the Women's Interagency HIV Study and 811 men (65% HIV-infected) in the Multicenter AIDS Cohort Study who underwent repeated B-mode carotid artery ultrasound imaging in 2004-2013. Outcomes included changes in right common carotid artery intima-media thickness (CCA-IMT) and new focal carotid artery plaque formation (IMT >1.5 mm) over median 7 years. We assessed the association between HIV serostatus and progression of subclinical atherosclerosis, adjusting for demographic, behavioral, and cardiometabolic risk factors. Results. Unadjusted mean CCA-IMT increased (725 to 752 µm in women, 757 to 790 µm in men), but CCA-IMT progression did not differ by HIV serostatus, either in combined or sex-specific analyses. Focal plaque prevalence increased from 8% to 15% in women and 25% to 34% in men over 7 years. HIV-infected individuals had 1.6-fold greater risk of new plaque formation compared with HIV-uninfected individuals (relative risk [RR] 1.61, 95% CI, 1.12-2.32), adjusting for cardiometabolic factors; the association was similar by sex. Increased plaque occurred even among persistently virologically suppressed HIV-infected individuals compared with uninfected individuals (RR 1.56, 95% CI, 1.07-2.27). HIV-infected individuals with baseline CD4+ ≥500 cells/µL had plaque risk not statistically different from uninfected individuals. Conclusions. HIV infection is associated with greater increases in focal plaque among women and men, potentially mediated by factors associated with immunodeficiency or HIV replication at levels below current limits of detection.
[Show abstract][Hide abstract] ABSTRACT: Tissue factor (TF) is a protein that mediates the initiation of the coagulation cascade. TF expression is increased in patients with poorly-controlled HIV, and may be associated with increased immune activation that leads to cardiovascular morbidity. The role of TF in immune activation in liver disease in hepatitis C virus (HCV)-monoinfection and HIV/HCV-coinfection has not been explored.
Fifty-nine patients were stratified: A) HIV-monoinfection (N = 15), B) HCV-monoinfection with chronic hepatitis C (CHC) (N = 15), C) HIV/HCV-coinfection with CHC (N = 14), and D) HIV/HCV-seropositive with cleared-HCV (N = 15). All HIV+ patients had undetectable HIV viremia. Whole blood was collected for CD4/CD8 immune activation markers by flow cytometry and plasma was assayed for microparticle TF (MPTF) activity. Subjects underwent transient elastography (TE) to stage liver fibrosis. Undetectable versus detectable MPTF was compared across strata using Fisher's Exact test.
MPTF activity was more frequently detected among patients with HCV-monoinfection (40%), compared to HIV-monoinfection and HIV/HCV-seropositive with cleared HCV (7%) and HIV/HCV-coinfection with CHC (14%)(p = 0.02). Mean TE-derived liver stiffness score in kPa was higher in patients with detectable MPTF (12.4 ± 8.5) than those with undetectable MPTF (6.4 ± 3.0)(p = 0.01). Mean CD4 + HLADR+ and CD4 + CD38-HLADR+ expression were higher in those with detectable MPTF (44 ± 9.8% and 38 ± 8.7%, respectively) than those with undetectable MPTF (36 ± 11% and 31 ± 10.4% respectively)(p = 0.05 and 0.04 respectively).
HCV-monoinfection and HIV/HCV-coinfection with CHC were associated with MPTF activity. MPTF activity is also associated with advanced liver fibrosis and with CD4 + HLADR+ immune activation.
[Show abstract][Hide abstract] ABSTRACT: Measurement of CD4+ T-lymphocytes (CD4) is a crucial parameter in the management of HIV patients, particularly in determining eligibility to initiate antiretroviral treatment (ART). A number of technologies exist for CD4 enumeration, with considerable variation in cost, complexity, and operational requirements. We conducted a systematic review of the performance of technologies for CD4 enumeration.
Studies were identified by searching electronic databases MEDLINE and EMBASE using a pre-defined search strategy. Data on test accuracy and precision included bias and limits of agreement with a reference standard, and misclassification probabilities around CD4 thresholds of 200 and 350 cells/μl over a clinically relevant range. The secondary outcome measure was test imprecision, expressed as % coefficient of variation. Thirty-two studies evaluating 15 CD4 technologies were included, of which less than half presented data on bias and misclassification compared to the same reference technology. At CD4 counts <350 cells/μl, bias ranged from -35.2 to +13.1 cells/μl while at counts >350 cells/μl, bias ranged from -70.7 to +47 cells/μl, compared to the BD FACSCount as a reference technology. Misclassification around the threshold of 350 cells/μl ranged from 1-29% for upward classification, resulting in under-treatment, and 7-68% for downward classification resulting in overtreatment. Less than half of these studies reported within laboratory precision or reproducibility of the CD4 values obtained.
A wide range of bias and percent misclassification around treatment thresholds were reported on the CD4 enumeration technologies included in this review, with few studies reporting assay precision. The lack of standardised methodology on test evaluation, including the use of different reference standards, is a barrier to assessing relative assay performance and could hinder the introduction of new point-of-care assays in countries where they are most needed.
PLoS ONE 03/2015; 10(3):e0115019. DOI:10.1371/journal.pone.0115019 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: All-cause mortality and serious non-AIDS events (SNAEs) in individuals with HIV-1 infection receiving antiretroviral therapy are associated with increased production of interleukin-6 which appears to be driven by monocyte/macrophage activation. Plasma levels of other cytokines or chemokines associated with immune activation might also be biomarkers of an increased risk of mortality and/or SNAEs.
Baseline plasma samples from 142 participants enrolled into the Strategies for Management of Antiretroviral Therapy study, who subsequently died, and 284 matched controls, were assayed for levels of 15 cytokines and chemokines. Cytokine and chemokine levels were analysed individually and when grouped according to function (innate/proinflammatory response, cell trafficking and cell activation/proliferation) for their association with the risk of subsequent death.
Higher plasma levels of proinflammatory cytokines (interleukin-6 and tumour necrosis factor-α) were associated with an increased risk of all-cause mortality but in analyses adjusted for potential confounders, only the association with interleukin-6 persisted. Increased plasma levels of the chemokine CXCL8 were also associated with all-cause mortality independently of hepatitis C virus status but not when analyses were adjusted for all confounders. In contrast, higher plasma levels of cytokines mediating cell activation/proliferation were not associated with a higher mortality risk and exhibited a weak protective effect when analysed as a group.
Whereas plasma levels of interleukin-6 are the most informative biomarker of cytokine dysregulation associated with all-cause mortality in individuals with HIV-1 infection, assessment of plasma levels of CXCL8 might provide information about causes of mortality and possibly SNAEs.
AIDS (London, England) 02/2015; 29(7). DOI:10.1097/QAD.0000000000000618 · 6.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chronic inflammation and immune activation occur in both HIV infection and normal ageing and are associated with inflammatory disease. However, the degree to which HIV influences age-related innate immune changes, and the biomarkers which best reflect them, remains unclear.
We measured established innate immune ageing biomarkers in 309 individuals including 88 virologically-suppressed (VS) and 52 viremic (viral load ≤ and >50 copies/ml respectively) HIV+ individuals. Levels of soluble (ie. CXCL10, soluble CD163, neopterin) and cellular (ie. proportions of inflammatory CD16+ monocytes) biomarkers of monocyte activation were increased in HIV+ individuals and were only partially ameliorated by viral suppression. Viremic and VS HIV+ individuals show levels of age-related monocyte activation biomarkers that are similar to uninfected controls aged 12 and 4 years older respectively. Viremic HIV infection was associated with an accelerated rate of change of some monocyte activation markers (eg. neopterin) with age, whilst in VS individuals, subsequent age-related changes occurred at a similar rate as in controls, albeit at a higher absolute level. We further identified CXCL10 as a robust soluble biomarker of monocyte activation, highlighting the potential utility of this chemokine as a prognostic marker.
These findings may partially explain the increased prevalence of inflammatory, age-related diseases in HIV+ individuals and potentially indicate the pathological mechanisms underlying these diseases which persist despite viral suppression.
[Show abstract][Hide abstract] ABSTRACT: With the advent of antiretroviral therapy that can control virus replication below the detection levels of conventional assays, a new clinical landscape of AIDS emerged, in which non-AIDS complications prevail over AIDS-defining conditions. These comorbidities are diverse and affect multiple organs, thus resulting in cardiovascular, kidney, neurocognitive and liver disease, osteopenia/osteoporosis, and cancers. A common feature of these conditions is that they are generally associated with accelerated aging. The mechanism behind these comorbidities is chronic excessive inflammation induced by HIV infection, which persists under antiretroviral therapy. Progressive simian immunodeficiency virus (SIV) infection of nonhuman primates (NHPs) closely reproduces these comorbidities and offers a simplified system in which most of the traditional human risk factors for comorbidities (i.e., smoking, hyperlipidemia) are absent. Additionally, experimental conditions can be properly controlled during a shorter course of disease for SIV infection. As such, NHPs can be employed to characterize new paradigms of AIDS pathogenesis and to test the efficacy of interventions aimed at alleviating non-AIDS-related comorbidities.
Current HIV/AIDS Reports 01/2015; 12(1). DOI:10.1007/s11904-014-0245-5
[Show abstract][Hide abstract] ABSTRACT: Interleukin-8 (IL-8, CXCL8) plays important roles in immune responses at mucosal sites including in the lower genital tract. Since several types of bacteria produce proteases that cleave IL-8 and many types of bacteria can be present in lower genital tract microbiota, we assessed genital fluids for IL-8 cleavage/alteration.
Genital fluids collected by lavage from 200 women (23 HIV-seronegative and 177 HIV-seropositive) were tested for IL-8 cleavage/alteration by ELISA.
IL-8 cleaving/altering activity was observed in fluids from both HIV-positive (28%) and HIV-negative women (35%). There was no clear relationship between the activity and the types of bacteria present in the lower genital tract as determined by high-throughput sequencing of the 16S rRNA gene. Protease inhibitors specific for matrix metalloproteinases (MMPs) reduced the activity and a multiplex assay that detects both inactive and active MMPs showed the presence of multiple MMPs, including MMP-1, -3, -7, -8, -9, -10 and -12 in genital secretions from many of the women. The IL-8-cleaving/altering activity significantly correlated with active MMP-9 as well as with cleavage of a substrate that is acted on by several active MMPs.
These studies show that multiple MMPs are present in the genital tract of women and strongly suggest that MMP-9 in genital secretions can cleave IL-8 at this mucosal site. These studies suggest that MMP-mediated cleavage of IL-8 can modulate inflammatory responses in the lower genital tract.
PLoS ONE 01/2015; 10(1):e0116911. DOI:10.1371/journal.pone.0116911 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Despite the use of HAART to control HIV, systemic immune activation and inflammation persists with the consequence of developing serious non-AIDS events. The mechanisms that contribute to persistent systemic immune activation have not been well defined. The intestine is the major source of "sterile" inflammation and plays a critical role in immune function; thus, we sought to determine whether intestinal gene expression was altered in virally controlled HIV+ individuals.
Gene expression was compared in biopsy samples collected from HIV- and HIV+ individuals from the ileum, right colon (ascending colon), and left colon (sigmoid). Affymetrix gene arrays were performed on tissues and pathway analyses were conducted. Gene expression was correlated with systemic markers of intestinal barrier dysfunction and inflammation and intestinal microbiota composition.
Genes involved in cellular immune response, cytokine signaling, pathogen-influenced signaling, humoral immune response, apoptosis, intracellular and second messenger signaling, cancer, organismal growth and development, and proliferation and development were upregulated in the intestine of HIV+ individuals with differences observed in the ileum, right, and left colon. Gene expression in the ileum primarily correlated with systemic markers of inflammation (e.g., IL7R, IL2, and TLR2 with serum TNF) whereas expression in the colon correlated with the microbiota community (e.g., IFNG, IL1B, and CD3G with Bacteroides).
These data demonstrate persistent, proinflammatory changes in the intestinal mucosa of virally suppressed HIV+ individuals. These changes in intestinal gene expression may be the consequence of or contribute to barrier dysfunction and intestinal dysbiosis observed in HIV.
AIDS (London, England) 01/2015; 29(5). DOI:10.1097/QAD.0000000000000569 · 6.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Previous studies have suggested that glycogen expression in the vaginal epithelium decreases during menopause, resulting in reduced levels of lactobacilli. However, free glycogen in genital fluids and its relationship with Lactobacillus levels have not been compared in premenopausal and postmenopausal women.
Eighty-two cervicovaginal lavage samples were collected at different phases of the menstrual cycle from 11 premenopausal (4 HIV-uninfected and 7 HIV-infected) and 12 postmenopausal (7 HIV-uninfected and 5 HIV-infected) women during a 1- to 3-month period. Free glycogen was quantified in genital fluids. Lactobacillus levels were quantified by real-time polymerase chain reaction. Estrogen and progesterone levels in blood were determined by enzyme-linked immunosorbent assay.
Free glycogen was detected in both premenopausal and postmenopausal women. Across all samples, those from postmenopausal women had significantly lower levels of free glycogen than those from premenopausal women (median, 0.002 vs 0.065 μg/μL, respectively; P = 0.03). Lactobacillus levels correlated positively with free glycogen in both premenopausal (Spearman r = 0.68, P < 0.0001) and postmenopausal (r = 0.60, P < 0.002) women. Samples from premenopausal women had higher Lactobacillus levels and lower vaginal pH (median log, 8.1; median pH, 4) than those from postmenopausal women (median log, 7.1; median pH, 4.6), although these differences were not significant. HIV status had no significant effect on these relationships.
Free glycogen is detected in both premenopausal and postmenopausal women and correlates with Lactobacillus in both groups. These results point to the complexity of the relationship between menopause and vaginal microbiota and indicate that more careful studies of the role of glycogen are warranted.
Menopause (New York, N.Y.) 12/2014; 22(7). DOI:10.1097/GME.0000000000000397 · 2.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abnormal levels of inflammation are associated with cardiovascular disease and mortality in human immunodeficiency virus (HIV)–infected
patients. Microbial translocation, which may cause inflammation, is decreased by sevelamer in patients undergoing hemodialysis.
In this single-arm study, we evaluated the effects of 8 weeks of sevelamer therapy on 36 HIV-infected subjects who were not
receiving antiretroviral therapy. Sevelamer did not significantly change markers of microbial translocation, inflammation,
or T-cell activation. During sevelamer treatment, however, levels of soluble tissue factor, low-density lipoprotein (LDL)
cholesterol, and oxidized LDL cholesterol decreased significantly, whereas D-dimer levels increased. Thus, in this study population,
sevelamer did not reduce microbial translocation but may have yielded cardiovascular benefits.
Clinical Trials Registration. NCT 01543958.
The Journal of Infectious Diseases 11/2014; 210(10). DOI:10.1093/infdis/jiu305 · 5.78 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abstract Investigations into apoptotic pathways, intrinsic and extrinsic, and the effects of highly active antiretroviral therapy (HAART) on T cell death via those pathways may provide insight into the mechanisms of and barriers to immune recovery. HIV-1-infected patients were enrolled into a randomized, controlled study of the immune effects of a lopinavir/ritonavir (LPV/r)-based versus an efavirenz (EFV)-based HAART regimen in antiretroviral-naive subjects with CD4(+) counts <350 cells/mm(3). Patients were randomized to receive TDF/FTC/EFZ or TDF/FTC plus LPV/r. Fourteen patients were enrolled and 10 patients completed 6 months of therapy as per the protocol. CD4(+) counts were measured before and during HAART therapy. We isolated T cell subsets to measure ex vivo apoptosis by propidium iodide staining. We also assessed caspase activation for the intrinsic and extrinsic pathways of apoptosis, as well as effector caspase activation. We also measured mitochondrial membrane potential. Cells were analyzed by flow cytometry. All patients had increased activation of caspase 8 (extrinsic pathway), caspase 9 (intrinsic pathway), effector caspases 3/7, and low mitochondrial membrane potential at baseline compared to controls. By 4 weeks, there was a decrease in activation of all caspases, but little further decrease by week 24. T cell mitochondrial membrane potential did not increase until week 12, but continued to increase until week 24. The only predictor of CD4(+) count increase was the increase in mitochondrial membrane potential of naive cells at 6 months (r=0.66, p=0.038). This suggests that positive selection of naive CD4(+) T cells in the thymus is the major determinant of CD4(+) recovery.
AIDS Research and Human Retroviruses 11/2014; 31(2). DOI:10.1089/aid.2014.0038 · 2.46 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Monocyte activation during HIV-1 infection is associated with increased plasma levels of inflammatory markers and increased risk for premature development of age-related diseases. Because activated monocytes primarily use glucose to support cellular metabolism, we hypothesized that chronic monocyte activation during HIV-1 infection induces a hypermetabolic response with increased glucose uptake. To test this hypothesis, we evaluated glucose transporter 1 (Glut1) expression and glucose uptake by monocyte subpopulations in HIV-seropositive (HIV(+)) treatment-naive individuals (n = 17), HIV(+) individuals on combination antiretroviral therapy with viral loads below detection (n = 11), and HIV-seronegative (HIV(-)) individuals (n = 16). Surface expression of Glut1 and cellular uptake of the fluorescent glucose analog 2-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amino)-2 deoxyglucose were analyzed by flow cytometry on monocyte subpopulations. Irrespective of treatment status, monocytes from HIV(+) persons had significantly increased surface expression of Glut1 compared with those from HIV(-) controls. Nonclassical (CD14(+)CD16(++)) and intermediate (CD14(++)CD16(+)) monocyte subpopulations showed higher Glut1 expression than did classical (CD14(++)CD16(-)) monocytes. Intermediate monocytes from treatment-naive HIV(+) individuals also showed increased uptake of 2-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amino)-2 deoxyglucose compared with those from HIV(-) controls. Our results show that HIV infection is associated with increased glucose metabolism in monocytes and that Glut1 expression by proinflammatory monocytes is a potential marker of inflammation in HIV-infected subjects. However, the possibility exists whereby other Gluts such as Glut3 and Glut4 may also support the influx of glucose into activated and inflammatory monocyte populations.
[Show abstract][Hide abstract] ABSTRACT: Background:Hepatitis C virus (HCV) viremia is thought to have broad systemic effects on the cellular immune system that go beyond its impact on just those T cells that are HCV specific. However, previous studies of chronic HCV and circulating T-cell subsets (activation and differentiation phenotypes) in HIV negatives used general population controls, rather than a risk-appropriate comparison group. Studies in HIV positives did not address overall immune status (total CD4(+) count).Methods:We used fresh blood from HIV-positive and at-risk HIV-negative women, with and without chronic HCV, to measure percentages of activated CD4(+) and CD8(+) T cells, Tregs, and T-cell differentiation phenotypes (naive, central memory, effector memory (EM), and terminally differentiated effector). This included 158 HIV negatives and 464 HIV positives, of whom 18 and 63, respectively, were HCV viremic.Results:In multivariate models of HIV negatives, HCV viremia was associated with 25% fewer naive CD4(+) (P = 0.03), 33% more EM CD4(+) (P = 0.0002), and 37% fewer central memory CD8(+) (P = 0.02) T cells. Among HIV positives, we observed only 1 of these 3 relationships: higher percentage of EM CD4(+) among HCV viremic women. Furthermore, the association with EM CD4(+) among HIV positives was limited to individuals with diminished immune status (total CD4(+) count 500 cells/L), as were associations of HCV viremia with higher percentages of activated CD4(+) and Tregs. Among HIV positives with high CD4(+) count, no significant associations were observed.Conclusions:These data suggest that HCV viremia in HIV negatives is associated with accelerated T-cell differentiation, but among HIV positives, the impact of HCV viremia is less straightforward and varies by total CD4(+) count.
[Show abstract][Hide abstract] ABSTRACT: Highly active antiretroviral therapy (HAART) for the treatment of HIV infection sustains viral suppression and increases CD4+ T cells in HIV patients. However, in 10-25% of subjects, known as immunological non-responders (INRs), HAART does not increase CD4 count. We investigated a potential role for galectin-9 and TIM-3 in INRs as galectin-9 and TIM-3 have been described to modulate NK and T cell function. PBMCs were isolated from healthy controls, HIV immunological responders (IRs, > 350 CD4+ cells/mm3) and HIV INRs (< 350 CD4+ cells/mm3) and TIM-3 and galectin-9 expressions on NK cell subsets and CD4+ T cells were assessed. HIV INRs and HIV IRs showed increased galectin-9 expression on CD16−CD56bright and CD16+CD56+ NK cells and CD4+ T cells. Only HIV INRs showed a reduced frequency of TIM-3-expressing CD16+CD56+, CD16+CD56− and CD4+ cells, which correlated with low peripheral CD4 counts. These data suggest that TIM-3 expression may be characteristic for HIV INRs.
[Show abstract][Hide abstract] ABSTRACT: Alterations in the gut microbiota composition are associated with food allergy. Toll-like receptors (TLR) respond to microbial stimuli. We studied the effects of ligation of TLR on intestinal epithelial cells (IEC) in preventing an allergic effector response. IEC monolayers (T84 cells) were co-cultured with CD3/28-activated PBMC from healthy controls or atopic patients and simultaneously apically exposed to TLR2, TLR4 or TLR9 ligands. The barrier integrity of T84 cell monolayers was significantly reduced upon co-culture with PBMC of food allergic subjects compared to healthy subjects. Apical exposure of IEC to TLR9, ligand prevented PBMC-induced epithelial barrier disruption. Using PBMC from food allergic subjects, apical TLR9 activation on IEC increased the IFN-γ/IL-13 and IL-10/IL-13 ratio, while suppressing pro-inflammatory IL-6, IL-8 and TNF-α production in an IEC-dependent manner. Hence, activation of apical TLR9 on IEC, potentially by microbiota-derived signals, may play an important role in the prevention of allergic inflammation.