The AIDS Disease of CD4C/HIV Transgenic Mice Shows Impaired Germinal Centers and Autoantibodies and Develops in the Absence of IFN-gamma and IL-6

The mechanisms responsible for degeneration of germinal centers (GC) and follicular dendritic cell (FDC) networks during progression to AIDS remain elusive. Here, we show that CD4(+) T cells from CD4C/HIV-1 Tg mice, which develop a severe AIDS-like disease, express low levels of CD40 ligand. Accordingly, GC formation, FDC networks, and immunoglobulin isotype switching are impaired in these animals. However, Tg B cells respond to in vitro CD40 stimulation. Total serum IgG levels are reduced in Tg mice, whereas total IgM levels are increased with a significant amount showing DNA specificity. IFN-gamma- and IL-6-deficient CD4C/HIV Tg mice also develop the AIDS-like disease and produce auto-Ab. Thus, CD4C/HIV Tg mice have immune dysfunction accompanied by autoimmune responses.