Reduced immune activation and T cell apoptosis in human immunodeficiency virus type 2 compared with type 1: Correlation of T cell apoptosis with beta(2) microglobulin concentration and disease evolution

This study analyzes the degree of immune activation and characterizes apopt osis in lymphocytes from healthy West African donors or patients infected w ith human immunodeficiency virus (HIV)-1 or -2, The lower decline of CD4 T cells in HIV-2- compared with HIV-1-infected donors is associated with lowe r levels of immune activation, evaluated by HLA-DR expression on lymphocyte s and sera concentrations of IgG and beta(2) microglobulin (beta(2)m), Ex v ivo apoptosis was found in both infections in all lymphocyte subsets, inclu ding CD4 and CD8 T cells, as well as B cells, but was lower in HIV-2 than i n HIV-1 infection, Interestingly, high correlations were found in HIV-2- an d HIV-1-infected donors between the level of CD4 T cell apoptosis and beta( 2)m concentration and progression of the disease. These observations suppor t the hypothesis that long-term activation of the immune system, weaker in HIV-2 infection, significantly contributes to T cell deletion and disease e volution.