Abstract
In mice deficient in the Fas/FasL apoptotic signaling pathways, T-dependent antibody responses to conventional environmental antigens are mechanistically distinct from the antibody responses to self-antigens. The latter appear to be initiated in the T cell rich inner PALS of the spleen, where the majority of antibody producing cells are located early in the disease process. The data are consistent with the premise that the inner PALS, and not germinal centers, is the major site of FasL regulation of B cell activity.