HIV-1 induces phenotypic and functional perturbations of B cells in chronically infected individuals

Abstract

A number of perturbations of B cells has been described in the setting of HIV infection; however, most remain poorly understood. To directly address the effect of HIV replication on B cell function, we investigated the capacity of B cells isolated from HIV-infected patients to respond to a variety of stimuli before and after reduction of viremia by effective antiretroviral therapy. B cells taken from patients with high levels of plasma viremia were defective in their proliferative responses to various stimuli. Viremia was also associated with the appearance of a subpopulation of B cells that expressed reduced levels of CD21. After fractionation into CD21 high - and CD21 low -expressing B cells, the CD21 low fraction showed dramatically reduced proliferation in response to B cell stimuli and enhanced secretion of immunoglobulins when compared with the CD21 high fraction. Electron microscopic analysis of each fraction revealed cells with plasmacytoid features in the CD21 low B cell population but not in the CD21 high fraction. These results indicate that HIV viremia induces the appearance of a subset of B cells whose function is impaired and which may be responsible for the hypergammaglobulinemia associated with HIV disease.