Objective: To investigate the features of B7-H1 expression on peripheral myeloid dendritic cells (mDCs) in patients with HIV infection and evaluate the correlations between B7-H1 expression and disease progression.
Methods: Peripheral blood samples from 82 treatment-naïve patients with HIV infection, 28 viral complete responders (CRs) under antiretroviral therapy (ART) and 14 healthy controls (HCs) were collected. Flow cytometry was applied to investigate the expression of B7-H1 on mDCs and CD4 cell counts. Plasma HIV-1 viral load was detected by bDNA.
Results: The frequency of B7-H1 expression on mDCs were 14.15% +/- 2.63%, 3.31% +/- 0.51% and 0.52% +/- 0.10% in AIDS patients, asymptomatic HIV infected individuals and HCs respectively. As compared with HCs, B7-H1 was significantly up-regulated on mDCs in HIV/AIDS patients. The order was as follows: AIDS patients > asymptomatic HIV infected individuals > HCs (all P < 0.05). Interestingly, the expression of B7-H1 on mDCs in long-term nonprogressors (LTNPs) was 3.12% +/- 1.14%. And it was lower than that in typical progressors (TPs) [8.12% +/- 1.37% (P = 0.001)]. Moreover, the expression of B7-H1 was negatively correlated with CD4 cell counts and positively correlated with plasma viral load in these patients (r = -0.631, P < 0.01 and r = 0.482, P < 0.01 respectively). The expression of B7-H1 on mDCs was significantly lower in ART complete responders than that in AIDS patients (6.59% +/- 1.43% vs 14.15% +/- 2.63%) (P < 0.01). Expression of B7-H1 on mDCs decreased markedly in patients whose CD4 cell counts greatly elevated after a successful antiretroviral treatment.
Conclusion: The expression of B7-H1 on mDCs is significantly up-regulated in HIV/AIDS patients. With a close correlation with disease status, it acts as a marker of disease progression.