Increased proportions of B cells with spontaneous production of interleukin-10 in HIV-infected individuals are normalized during combination antiretroviral therapy: a longitudinal study.

Interleukin-10 (IL-10)-producing B cells (B10 cells) may inhibit HIV-specific T cells and are elevated in untreated HIV infection. We aimed to determine the effect of combination antiretroviral treatment (cART) on the proportion of B10 cells. Furthermore, we compared B10-cell proportions in HIV-infected progressors and viremic controllers. This was a prospective study including HIV-infected progressors, viremic controllers and healthy controls. Progressors initiating cART were followed for 6 months. Purified B cells were stimulated with CpG, alone or in combination with HIV gp120, and the proportion of B10 cells was measured by flow cytometry. Without stimulation, the B10-cell proportion was higher in progressors than in healthy controls, while viremic controllers and healthy controls had comparable proportions. Moreover, the proportion of CD24hi CD38hi transitional B cells was higher in progressors than in healthy controls. After initiation of cART, the proportion of B10 cells and transitional B cells decreased. In conclusion, progressors had elevated B10-cell proportions, while viremic controllers displayed normal proportions. After initiation of cART, the B10-cell proportion decreased. This could limit B10-cell-mediated suppression of specific CD8+ T-cell responses.