| As the most important antigen presentation cells (APC), dendritic cells (DCs) commonly play a central role in clearing virus infections in humans. After capturing antigens, DCs migrate to lymphoid organs and are induced to undergo phenotypic and functional changes that culminate in the complete transition from antigen-capturing cells to APC. After maturation, DCs display peptide-major histocompatibility complexes I and II , and then they process and present antigens to T-cells and result in the induction of CD4+ and CD8+ T-cell antiviral immune responses as well as B-cell proliferation. In chronically hepatitis B virus (HBV)-infected patients, adaptive immune responses to HBV were absent or not strong enough to clearthe virus and the function of DCs was proved impaired to some extent. HBV infection itself could influence the function of immune cells in humans. But when HBV infections were effectively inhibited, the consecutive changes of host immune responses especially the function of DCs and numbers of lymphocyte subsets were rarely investigated and reported.So in the study 22 patients with chronic HBV infection (CHB) and 10 healthy blood donors were enrolled. Monocytes from peripheral blood were separated and induced into DCI in 10% fetal bovine serum (FBS) culture medium supplemented with cytokine (GM-CSF and IL-4). Phenotypic molecules of DCI were detected by flow cytometry analysis in these CHB patients and healthy controls. Simultaneously, biochemical marker, HBV DNA level and lymphocyte subsets of patients were recorded. Sixteen patients received lamivudine therapy in our study, among them 11 patients were lamivudine-effective which were judged by HBV DNA negativity and ALT normalization, and 5 were lamivudine-resistant which marked by appearance of HBV genome YMDD variation in serum. We try to explore the relationship between DC1 change and chronic HBV infection. We also observed theimpact of lamivudine treatment on DC1 function and lymphocyte subset number consecutively. We also want to know the change of DC1 function and lymphocyte subset numbers in patients with YMDD variation and provide evidence for clinical therapy.The results showed that when monocytes were induced by RPMI1640 culture medium supplemented by GM-CSF and IL-4, cells began to proliferate after 48 h culture. On day 5, TNF- a were added to mature DC1. On day 9, DC1 proliferation reached maximum. In the same culture condition, DC1 proliferation rate was lower from CHB patients than that from healthy people. Through microscope we observed that DC1 from healthy people showed more clusters and displayed more dendrites than those from CHB patients. All these proved that DC1 yield from CHB patients was lower than in normal controls.Using flow cytometry analysis, phenotypic molecules of DC 1 in CHB patients and healthy people were detected. The results showed that DC1 cultured from CHB patients showed statistically significant lower expression of CD80 (40.29 10.54 V 87.62 9.67), CD86 (23.67 8.96 V 84.38 9.72), CDla (7.88 6.73 V 89.56 8.96) and HLA-DR (28.85 11.51 V 92.47 9.34). CD40 and CD83expression were also decreased in CHB patients than those in healthy people. Therefore we concluded that DC1 were not only quantitatively but also qualitatively decreased in CHB patients in comparison with normal controls. Because all patients with CHB infection were HBV DNA positive in serum, so the dysfunction of DC1 might be partly related to HBV DNA replication in these patients.Comparison of lymphocyte subsets numbers between CHB patients and healthy people showed that CD4+ T-cells were higher but CD8+ T-cells and NK cells were lower and CD4/CD8 were higher in these patients. The imbalance of CD4/CD8 ratio and lower CD8+ T-cells as well as NK cells indicated in these patients the adaptive and innate immune responses were both impaired, both of which might related to the failure of HBV clearance in humans.We consecutively observed changes of DC1 proliferation and surface markers before and after 48 weeks lamivudine tr... |
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