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-gamma) 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-1beta, with or without IFN-gamma, 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-gamma. 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.

FIG. 1.

Effect of HCV and HIV-1 infection of DCs and treatment with CD40L and inflammatory cytokines on expression of DC phenotypic markers. The data are the means ± standard errors for MFI and DCs expressing the various markers. P was not significant within the DC treatments for the five DC markers compared across the four groups of study subjects. HCV(−), HCV negative; HIV-1(−), HIV-1 negative; HCV(+), HCV positive; HIV-1(+), HIV-1 positive.

FIG. 2.

Production of IL-12 p70 (A) and IL-12 p40 (B) by CD40- and CD40L-IFN-γ-treated DCs from HCV- and HIV-1-infected subjects and virus-negative controls. The data are mean ± standard error levels (pg/ml) of IL-12 p70 and p40 production by DCs in response to the treatments shown. (A) Analysis within each group showed that DCs from the four groups of subjects that were treated with either CD40L or CD40L-IFN-γ produced more IL-12 p70 than untreated DCs at 24 h and 48 h (P < 0.05). DCs that were treated with CD40L-IFN-γ produced larger amounts of IL-12 p70 than DCs treated with CD40L for the HCV-negative/HIV-1-negative and HCV-negative/HIV-1-positive groups at 24 h and for all four groups at 48 h (P < 0.05). Analysis across the four groups showed that the levels of IL-12 p70 produced by DCs treated with CD40L from the HCV-positive/HIV-1-negative and HCV-positive/HIV-1-positive groups were lower than the levels produced by the HCV-negative/HIV-1-negative and HCV-negative/HIV-1-positive groups (P < 0.05). The levels of IL-12 p70 produced by DCs treated with CD40L-IFN-γ were comparable among the four groups of study subjects (P was not significant). (B) Analysis within each group showed that DCs from the four groups of subjects that were treated with either CD40L or CD40L-IFN-γ produced more IL-12 p40 than untreated DCs at 24 h and 48 h (P < 0.05). DCs from all of the groups that were treated with CD40L produced larger amounts of IL-12 p40 than IL-12 p70 at 24 h and 48 h (P < 0.05). DCs from all of the groups that were treated with CD40L-IFN-γ produced larger amounts of IL-12 p40 than DCs treated with CD40L at 24 h and 48 h (P < 0.001). Analysis across the four groups showed that the levels of IL-12 p40 produced by DCs treated with CD40L were higher at 48 h for the HCV-negative/HIV-1-negative group than for the HCV-positive/HIV-1-positive group (P < 0.03) but not for the other two groups (P was not significant). The levels of IL-12 p40 produced by DCs treated with CD40L-IFN-γ were comparable among the four groups of study subjects at 24 h and 48 h (P was not significant). HCV(−), HCV negative; HIV-1(−), HIV-1 negative; HCV(+), HCV positive; HIV-1(+), HIV-1 positive.

FIG. 3.

Production of IL-12 p70 (A) and IL-12 p40 (B) by IL-1β-TNF-α- and IL-1β-TNF-α-IFN-γ-treated DCs from HCV- and HIV-1-infected subjects and virus-negative controls. The data are the mean ± standard error levels (pg/ml) of IL-12 p70 and p40 production by DCs in response to the treatments shown. (A) Analysis within each group showed that the treatment of DCs from the four groups of subjects with IL-1β-TNF-α-IFN-γ but not IL-1β-TNF-α increased the levels of IL-12 p70 production at 24 h and 48 h compared to that at 0 h (P < 0.05). IL-1β-TNF-α-IFN-γ-treated DCs from the four groups produced more IL-12 p70 than IL-1β-TNF-α-treated or untreated DCs at 48 h (P < 0.05). Analysis across the four groups showed that the levels of IL-12 p70 produced by DCs treated with IL-1β-TNF-α or IL-1β-TNF-α-IFN-γ were comparable at 24 h and 48 h (P was not significant). (B) Analysis within each group showed that DCs from the four groups of subjects that were treated with either IL-1β-TNF-α or IL-1β-TNF-α-IFN-γ produced more IL-12 p40 at 24 h and 48 h than at 0 h (P < 0.05). DCs from all of the groups that were treated with IL-1β-TNF-α or IL-1β-TNF-α-IFN-γ produced larger amounts of IL-12 p40 than IL-12 p70 at 24 h (P < 0.05). DCs from the study groups that were treated with IL-1β-TNF-α or IL-1β-TNF-α-IFN-γ produced larger amounts of IL-12 p40 compared to the amounts produced by untreated DCs at 24 h and 48 h (P < 0.05), except for DCs from the HCV-negative/HIV-1-positive group at 24 h and 48 h (P was not significant). DCs from the HCV-negative/HIV-1-negative and HCV-negative/HIV-1-positive groups treated with IL-1β-TNF-α-IFN-γ produced more IL-12 p40 than DCs treated with IL-1β-TNF-α at 24 h and 48 h (P < 0.01). Analysis across the four groups showed that the levels of IL-12 p40 produced by DCs from the HCV-negative/HIV-1-positive group and the HCV-positive/HIV-1-positive group treated with IL-1β-TNF-α were lower than the levels produced by DCs from the HCV-negative/HIV-1-negative group at 48 h (P < 0.03) but not at 24 h (P was not significant). The levels of IL-12 p40 produced by DCs from all three virus-infected groups treated with IL-1β-TNF-α-IFN-γ were lower than those produced by DCs from the HCV-negative/HIV-1-negative group at 24 h and 48 h (P < 0.05). HCV(−), HCV negative; HIV-1(−), HIV-1 negative; HCV(+), HCV positive; HIV-1(+), HIV-1 positive.

FIG. 4.

Production of IL-15 (A) and IL-10 (B) by DCs from HCV- and HIV-1-infected subjects. The data are the mean ± standard error levels (pg/ml) of IL-15 or IL-10 production by DCs in response to the treatments shown. (A) Analysis within each group showed that DCs from all of the groups produced more IL-15 at 24 h and 48 h than at 0 h and that DCs treated with CD40L or CD40L-IFN-γ produced more IL-15 than untreated DCs at 24 h and 48 h (P < 0.05). Analysis across the four groups of study subjects showed that DCs treated with CD40L or CD40L-IFN-γ produced comparable levels of IL-15 at 24 and 48 h (P was not significant). (B) Analysis within each group showed that DCs from the four groups treated with CD40L or CD40L-IFN-γ produced more IL-10 at 24 h and 48 h than at 0 h (P < 0.05). DCs from the four groups treated with CD40L or CD40L-IFN-γ produced more IL-10 than untreated DCs did at 48 h (P < 0.05). Analysis across the four groups showed that there was a lower level of production of IL-10 by untreated DCs at 0 h for the two groups of HCV-infected subjects than for the uninfected or HIV-1-monoinfected groups, which remained lower through the 48 h (P < 0.05). Compared to the level of IL-10 production by DCs from the HCV-negative/HIV-1-negative group that were treated with CD40L or CD40L-IFN-γ, the level of IL-10 production by DCs that were treated with CD40L or CD40L-IFN-γ was lower for the HCV-positive/HIV-1-positive group at 24 h and 48 h (P < 0.05). HCV(−), HCV negative; HIV-1(−), HIV-1 negative; HCV(+), HCV positive; HIV-1(+), HIV-1 positive.

FIG. 5.

Increase in IL-12 p70 and decrease in IL-10 at 24 h by blocking with the anti-IL-10 MAb of DCs from HCV-positive/HIV-1-negative and HCV-positive/HIV-1-positive groups treated with CD40L. P was <0.05 for IL-12 p70 production by CD40L-treated DCs from the two HCV-positive groups compared to those from the HCV-negative/HIV-1-negative group. HCV(−), HCV negative; HIV-1(−), HIV-1 negative; HCV(+), HCV positive; HIV-1(+), HIV-1 positive.

FIG. 6.

MLR (mean cpm of triplicate cultures) of purified, allogeneic CD4⁺ and CD8⁺ T cells in response to DCs that were treated with various immunomodulators.

FIG. 7.

Stimulation of blastogenesis of CD4⁺ T cells from healthy donors in an MLR by DCs from HCV-infected, HIV-1-infected, and HCV- and HIV-1-coinfected subjects that were treated in vitro with various immunomodulators. P was not significant for DCs treated with CD40L-IFN-γ and CD40L alone within each group and among the four groups of study subjects; for DCs treated with IFN-γ, P was <0.05 within each group of study subjects. HCV(−), HCV negative; HIV-1(−), HIV-1 negative; HCV(+), HCV positive; HIV-1(+), HIV-1 positive.

FIG. 8.

Production of IL-2 (A), IL-5 (B), and IL-10 (C) in MLR cultures of DCs from HCV- and HIV-1-infected subjects and purified CD4⁺ T cells from healthy donors. P was not significant for DCs treated with CD40L or CD40L-IFN-γ within each group and among the four groups of study subjects. HCV(−), HCV negative; HIV-1(−), HIV-1 negative; HCV(+), HCV positive; HIV-1(+), HIV-1 positive.