Killer T cells regulate antigen presentation for early expansion of memory, but not naive, CD8( ) T cell

Abstract

Antigen presentation within the lymph node draining a site of infection is crucial for initiation of cytotoxic T cell responses. Precisely how this antigen presentation regulates T cell expansion in vivo is unclear. Here, we show that, in primary infection, antigen presentation peaks approximately 3 days postinfection and then slowly decays until day 12. This prolonged antigen presentation is required for optimal expansion of naive CD8(+) T cells, because early ablation of dendritic cells reduces the later CD8(+) T cell response. Antigen presentation during secondary infection was 10-fold lower in magnitude and largely terminated by day 4 postinfection. Expansion of memory, but not naive, an..