Dendritic Cell Function during Chronic Hepatitis C Virus and Human Immunodeficiency Virus Type 1 Infection

Abstract

Hepatitis C virus (HCV) infection can persist despite HCV-specific T-cell immunity and can have a more aggressive course in persons coinfected with human immunodeficiency virus type 1 (HIV-1). Defects in antigen-presenting, myeloid dendritic cells (DCs) could underlie this T-cell dysfunction. Here we show that monocyte-derived DCs from persons with chronic HCV infection, with or without HIV-1 coinfection, being treated with combination antiretroviral therapy produced lower levels of interleukin 12 (IL-12) p70 in response to CD40 ligand (CD40L), whereas the expression of DC surface activation and costimulatory molecules was unimpaired. The deficiency in IL-12 production could be overcome by addition of gamma interferon (IFN-γ) with CD40L, resulting in very high, comparable levels of IL-12 production by DCs from HCV- and HIV-1-infected subjects. Smaller amounts of IL-12 p70 were produced by DCs treated with the immune modulators tumor necrosis factor alpha and IL-1β, with or without IFN-γ, and the amounts did not differ among the uninfected and infected subjects. Blocking of IL-10 with an anti-IL-10 monoclonal antibody in the CD40L-stimulated DC cultures from HCV-infected persons increased the level of IL-12 p70 production. The ability of DCs from HCV-infected persons to stimulate allogeneic CD4+ T cells or induce IL-2, IL-5, or IL-10 in a mixed lymphocyte reaction was not impaired. Thus, myeloid DCs derived from persons with chronic HCV infection or with both HCV and HIV-1 infections have defects in IL-12 p70 production related to IL-10 activity that can be overcome by treatment of the DCs with CD40L and IFN-γ. DCs from these infected subjects have a normal capacity to stimulate CD4+ T cells. The functional effectiveness of DCs derived from HCV-infected individuals provides a rationale for the DC-based immunotherapy of chronic HCV infection.

Th2 Polarization in Peripheral Blood Mononuclear Cells from Human Immunodeficiency Virus (HIV)-Infected Subjects, as Activated by HIV Virus-Like Particles

“…The present results confirm and extend data from others showing a normal expression of surface molecules involved in antigen-specific T-cell activation on immature and mature DCs from HIV-1-infected and hepatitis C virus (HCV)-HIV-coinfected individuals (15,25,31). Furthermore, monocyte-derived DCs from either HCV-infected or HCV-HIV-coinfected persons have been previously shown to stimulate a mixed leuko- cyte reaction in purified, allogeneic CD4 ϩ T cells comparable to that with DCs derived from healthy donors (36,44,54).…”

“…Therefore, the high levels of IL-10 and TNF-␣ induced by HIV-VLPs could explain the lack of increased production of IL-12 p70 in all tested groups and the limited production of IFN-␥ only in the seronegative group. The impairment of basal and antigen-induced production of Th1-polarizing cytokines for HIV-seropositive individuals is in concordance with previous observations of PBMCs from HIVinfected subjects exposed ex vivo to a panel of stimuli (i.e., Staphylococcus aureus, bacterial cell wall components) (25,39). The correlation of the lymphokine response with the extent of stimulation of CD83, CD86, CD80, and HLA-DR markers for each subject of each group is currently under evaluation.…”

Primary Human Immunodeficiency Virus Type 1-Specific CD8+T-Cell Responses Induced by Myeloid Dendritic Cells

“…We have previously shown that CD40L-matured moDC are superior to immature DC in priming of CD8 ϩ T cells to HIV-1 peptides and proteins (25). Moreover, we have also recently shown that moDC matured with CD40L and IFN-␥ produce greater amounts of IL-12 than do CD40L-matured DC (16), which is important for activation of antigenspecific CD8…”

“…The moDC were derived by culture of the purified blood monocytes with 1,000 U/ml recombinant GM-CSF (Amgen, Thousand Oaks, CA) and 1,000 U/ml recombinant IL-4 (R&D Systems, Minneapolis, MN) (24). Immature moDC were treated on day 5 with CD40L (0.5 g/ml; Amgen or Alexis, San Diego, CA) and gamma interferon (IFN-␥) (1,000 U/ml; R&D) (16) or with a combination of inflammatory cytokines and prostaglandin E2 (PGE2), i.e., IL-1␤ (2 ng/ml; R&D), IL-6 (1,000 IU/ml; R&D), tumor necrosis factor alpha (TNF-␣) (10 ng/ml; R&D), and PGE2 (5 M; Pfizer, Vienna, Austria), for 40 h to induce DC maturation (27).…”

“…For priming of the adult donor T cells, PBMC were obtained from the same HIV-1 negative, unrelated adult subjects used for deriving the DC. Autologous moDC matured with CD40L and IFN-␥ (16,23) were incubated with 50 g/ml of peptides in RPMI 1640 medium (GIBCO, Grand Island, NY) for 2 h at 37°C in a 5% CO 2 atmosphere (62). The DC were harvested and resuspended with autologous PBMC depleted of CD14 ϩ monocytes (as described above) or CD8 ϩ T cells using anti-CD8 MAb microbeads (Miltenyi Biotec, Auburn, CA) where indicated, at a responder-tostimulator (T-cell/DC) ratio of 10:1.…”