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HLA-B*57 affects the course of HIV infection. Under antiretroviral therapy, its effects cannot be explained by outstandingly efficient T cell responses alone but may also involve cells of innate immunity. Studying in vitro stimulation with Pam3CSK4, E. coli LPS-B5 and CpG-ODN-2216, we observed greater induction of IL-6/IL-1beta double-positive CD14+CD16++ monocytes as well as IFN-gamma-positive cytotoxic CD56highCD16neg NK cells in HLA-B*57- versus HLA-B*44-positive HIV patients, while TNF-alpha induction remained unchanged. Differences were not seen in the other monocyte and NK cell subsets or in HLA-matched healthy controls. Our findings show that, in virally suppressed HIV infection, HLA-B*57 is associated with enhanced responsiveness of inflammatory innate immune cells to TLR ligands, possibly contributing to increased vulnerability in sepsis. KEY MESSAGES: • HLA-B*57 is a host factor affecting clinical outcomes of HIV infection. • HLA-B*57 modifies inflammatory subsets of NK cells and monocytes in HIV infection. • In HLA-B*57-positive HIV patients TLR agonists induce enhanced IL-6/IL-1beta in monocytes. • NK cells from HLA-B*57 HIV patients release more IFN-gamma upon TLR costimulation. • HLA-B*57 is linked to enhanced inflammatory responsiveness to TLR ligands.

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HIV/HCV infection is supposed to substantially reduce survival as compared to HIV mono-infection. Here, we compared longtime-survival and causes of death in a cohort of HIV- and HIV/HCV-co-infected patients on combined antiretroviral therapy (cART), before introduction of HCV direct acting antivirals (DAA). 322 Caucasian patients with HIV (n = 176) and HIV/HCV-infection (n = 146) were enrolled into this study. All patients were recruited between 2003 and 2004 and followed until 01.01.2014. We compared overall survival between the two groups by the Kaplan-Meyer method and identified independent factors associated with long-time survival by conditional Cox regression analysis. In total 46 (14.3%) patients died during the observation period (HIV infection: n = 23 (13.1%), HIV/HCV infection: n = 23 (15.8%) but overall-survival did not differ significantly between HIV/HCV-infected and HIV mono-infected patients (p = 0.619). Survival was substantially better in patients with complete suppression of HIV replication below the level of detection than in those with residual viremia (p = 0.001). Age (p = 0.008), γ-glutamyltranspeptidase (p < 0.0001) and bilirubin (p = 0.008) were significant predictors of survival irrespective from HCV co-infection. Complete repression of HIV replication on cART is the key factor determining survival both in HIV- and HIV/HCV-co-infected patients, while HCV co-infection and therapy without DAAs seem to affect survival to a lesser extent. Thus, patients with HIV/HCV co-infection require particularly intensive cART.

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INTRODUCTION: Impaired activity of natural killer (NK) cells has been proposed as a mechanism contributing to viral persistence in hepatitis C virus (HCV) infection. As the function of NK cells is primarily regulated by NK cell receptors (NKR), we analysed whether decreased NK cell function in hepatitis C may be related to dysregulated NKR expression. PATIENTS AND METHODS: Expression of NK cell was analysed by flow cytometry on lymphocytes from HCV(+) subjects (n = 30), patients who became HCV(-) after antiviral therapy (n = 10), healthy individuals (n = 10), and hepatitis B virus (HBV) infected patients (n = 9). Cytolytic function of lymphocytes was studied in a redirected lysis assay and in a standard 51chromium release cytotoxicity assay, respectively. RESULTS: In patients with chronic hepatitis C, we found a significantly reduced proportion of NKp46 and NKp30 expressing NK cells compared with healthy and HBV infected subjects. Low expression of natural cytotoxicity receptor (NCR) was also confirmed in in vitro activated NK cell populations derived from HCV patients compared with uninfected donors. In contrast, patients who cleared HCV under antiviral therapy showed normal expression of NKp44, NKp30, and NKp46. Reduced NCR expression in chronic hepatitis C was associated with a parallel decrease in NCR mediated target cell killing. Furthermore, we found a significantly increased proportion of NKG2A expressing NK cells and CD8+ T cells in HCV positive patients, resulting in a reduced cytolytic activity against cells incubated with the HLA-E stabilising peptide HCV core35-44. CONCLUSION: The present study indicates that defective expression of NKR represents a novel mechanism contributing to impaired function of NK cells and CD8+ T cells in chronic hepatitis C.

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Successful elimination of the hepatitis C virus (HCV) during acute infection has been linked to strong HCV-specific in vitro T-cell proliferation, whereas T cells from patients with chronic hepatitis C respond only weakly to HCV antigens. Lipid-coupled peptides are immunostimulants, which might provide a basis for novel therapeutic strategies against HCV. Therefore, in 20 patients with chronic hepatitis C, we studied whether tri-palmitoyl-S-cysteine-coupled peptides could modify in vitro T-cell proliferation (by [3H]thymidine uptake) in response to virus core and NS4. The lipopeptides corresponded to five immunodominant T helper epitopes of HCV core. Contrary to unmodified peptides, the lipopeptides specifically enhanced [3H]thymidine uptake in response to HCV antigens but not to a non-HCV related control antigen. They increased the frequency of responders (stimulation index, SI > or = 4) to core (13/20 versus 2/20; p = 0.0008) and NS4 (20/20 versus 7/20; p < 0.0001) among our patients with chronic hepatitis C. This immunostimulatory effect was dose-dependent, and was observed specifically with lipopeptides corresponding to the HCV epitopes. Our data demonstrate that the poor in vitro T-cell proliferation of patients with chronic hepatitis C can be improved when T cells are co-stimulated with HCV core-derived T helper lipopeptides, while the same peptides in unlipidated form had no effects. Thus, lipopeptides corresponding to HCV T-cell epitopes may offer novel immunomodulatory strategies against HCV.

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OBJECTIVE: To assess biochemical characteristics of adrenarche in patients with myelomeningocele (MMC), we examined serum levels of dehydroepiandrosterone sulfate (DHEAS) in prepubertal MMC patients. PATIENTS AND METHODS: The study included a total of 54 prepubertal patients with MMC and shunted hydrocephalus: 13 patients (2 m, 11 f; aged 4.6-10.1 years, mean 8.1 +/- 0.4) with isolated pubarche (Tanner stage PH 2-4, B1 or testes volume < or =3 ml) and 41 prepubertal MMC patients without pubarche (17 m, 24 f; aged 2.0-11.9 years; mean 6.8 +/- 2.5). DHEAS levels were measured directly by chemiluminescence immunoassay (Nichols, USA). Auxological data (supine length, body mass index (BMI), arm span) and bone age (BA) were recorded. RESULTS: (mean +/- SD): Basal DHEAS levels correlated with chronological age (CA) (r = 0.32, p < 0.05), BA (r = 0.65, p < 0.01; n = 23), BMI (r = 0.54, p < 0.01) and pubic hair stage (PH1 vs. PH2-4, r = 0.49, p < 0.01). 10/11 patients aged 2-4 years had DHEAS levels in the normal range, whereas 18/40 (45.0%) of the 5- to 9-year-old patients showed elevated levels (>+2 SDS). Ten patients with isolated pubarche (10/13; 2 m, 8 f; CA 8.3 +/- 1.5 years) and 9 patients without pubarche (9/41; 6 m, 3 f; CA 6.9 +/- 2.1 years) had elevated DHEAS levels (+6.34 and +4.05 SDS, respectively). The values correlated with BA/CA ratio (p < 0.05, n = 23). There was a trend to higher BMI SDS levels in patients with elevated DHEAS levels. CONCLUSION: Our data show an early and increased activation of adrenal androgen secretion in MMC patients.

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BACKGROUND/METHODS: To characterize the repertoire of T-cell epitopes on the hepatitis C virus (HCV) core protein, we studied major histocompatibility complex (MHC) class I binding of 75 decapeptides on 20 human B-cell lines and murine spleen cells using a flow cytometric assay. The results were compared with MHC class I stabilization on T2 cells, the SYFPEITHI algorithm, and known T-cell epitopes from the literature. RESULTS: Binding of peptides proved to be specific for MHC class I molecules. We observed peak fluorescence signals at positions amino acids (aa) 35-44, aa 87-96, aa 131-140, and aa 167-176 in virtually all HLA-A2-positive cell lines. These sites corresponded to T-cell epitopes predicted by SYFPEITHI and the positions of known T-cell epitopes, whereas T2 stabilization was at variance for two peptides. The assay was applied to HLA-A2-negative cells and murine spleen cells without further modification, and identified additional peptides, corresponding to known T-cell epitopes. CONCLUSIONS: Peptide binding to different MHC class I alleles can be mapped rapidly by a flow cytometric assay and enables a first orientation on the sites of possible T-cell epitopes. Application of this assay to HCV core suggests a rather limited repertoire of epitopes in the Caucasoid population.

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T helper lymphocytes are important regulatory cells for the immune response in chronic hepatitis C. They recognize peptides, which are generated from the viral proteins by antigen processing and are bound to MHC (major histocompatibility complex) class II molecules. However, antigen processing might also result in non-immunogenic peptide fragments that can modify T cell activation. - To identify such peptide fragments in hepatitis C, we studied binding of 15 synthetic HCV core derived peptides to MHC class II molecules of 9 human homozygous typing B cell lines (HT-BCLs) as well as T cell proliferation in 41 HLA-typed patients with chronic hepatitis C. - We identified a peptide (HCV core aa 59-83) which bound to 7 HT-BCLs, whereas PBMC of only 2 out of 36 patients with the corresponding HLA-DR alleles proliferated in response to this peptide. Competition experiments indicated that small amounts of peptide aa 59-83 specifically inhibited the proliferative response to the recombinant core protein but not to core derived immunogenic peptides. Our data show that a peptide fragment from the HCV core region aa 59-83 can interfere in vitro with immune recognition of the HCV core protein.

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BACKGROUND/AIM: Since the outcome of hepatitis C infection appears to be correlated with the immune response to the HCV core protein, the aim of this study was to investigate the T cell response to hepatitis C virus core and core-derived antigens. METHODS: As this response may be regulated importantly by differential secretion of cytokines, we determined the number of peripheral blood mononuclear cells (PBMC) that secreted IL-2, IL-4, IL-10, and IFN-gamma in response to a recombinant HCV core protein and a panel of 19 core-derived peptides, using the ELI-Spot-technique. Two groups of patients were studied: group A: 11 patients with previously self-limited HCV infection; group B: 12 patients with chronic hepatitis C. RESULTS: In group B significantly less IFN-gamma spot forming cells (SFC) could be detected, both after stimulation with the core protein (0.083+/-0.083 SFC vs. 1.3+/-0.4 SFC/10(5) PBMC; p = 0.005 and with the core-derived peptides (1.3+/-0.5 vs. 4.4+/-1.1 SFC SFC/10(5) PBMC; p = 0.007). By analyzing the cytokine response to each single peptide, we found IFN-gamma responses to peptides aa 39-63 and aa 148-172 in group A but not in group B (p<0.03). In group B also, fewer IL-2 secreting cells were found after peptide stimulation (p = 0.04). Whereas subjects of group B showed IL-10-specific responses to HCV peptides more frequently than patients with self-limiting hepatitis C (p = 0.03), the number of IL-4-producing cells was not different between the two groups. CONCLUSIONS: The data suggest that patients with persistent viremia and chronic liver disease (group B) have less PBMC showing type 1 cytokine (IL-2, IFN-gamma) responses to HCV core protein than patients with self-limited HCV infection (group A).

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