Defects in Apoptosis Increase Memory CD8+ T cells Following Infection of Bim^-/- Fas^lpr/lpr Mice
Apoptosis, Viral infection, Cytolytic T cells
During many infections, large numbers of effector CD8+ T cells are generated. After pathogen clearance, the majority of these cells undergo apoptosis, while the survivors differentiate into memory CD8+ T cells. Although loss of both Bim and Fas function dramatically increased antigen-specific CD8+ T cells in the lymph nodes following acute lymphocytic choriomeningitis virus (LCMV) infection, it was unclear whether they were pardoned effector or true memory CD8+ T cells. In this study, we demonstrate they are bona fide memory T cells as characterized by surface marker expression, cytokine production, homeostatic proliferation, and ability to clear a secondary challenge of pathogen. Loss of both Bim and Fas also increased the number of virus-specific CD4+ T cells found in the lymph nodes compared to the parental genotypes or wildtype mice. These studies illustrate that decreasing apoptosis increases the number of memory T cells and therefore could increase the efficacy of vaccines.
Weant, Ashley E.; Ryan D. Michalek; Katie E. Crump; Andrew P. Konopitski; and Jason M. Grayson. 2011. "Defects in Apoptosis Increase Memory CD8+ T cells Following Infection of Bim^-/- Fas^lpr/lpr Mice." Cellular Immunology 271, (2): 256-266. doi:10.1016/j.cellimm.2011.07.003.