Peptide-induced deletion of CD8 T cells in vivo occurs via apoptosis in situ

The ultimate fate of T cells undergoing antigen-induced cell death in vivoremains controversial. Whereas apoptosis of CD4+ T cells driven bysuperantigen is readily detectable in lymphoid organs, CD8+ T cells havebeen reported to disappear from the lymphoid organs and accumulate in theliver where they undergo apoptosis. Using transgenic mice that producelarge numbers of ovalbumin-specific CD8+ T cells (OT-I cells), we were ableto investigate the events that follow soluble peptide administration in anindependent CD8+ T cell system. Here we show that the OT-I cells undergoproliferation and apoptosis in situ in lymphoid organs in response toantigenic stimulation with no evidence for liver involvement. This issimilar to the course of events found for CD4+ T cell activation andcounters the view that the liver is a general site for CD8+ T cellclearance following antigen-specific activation.