Figure 2.

Progression of clonal exhaustion during persistent infection. This figure, based on persistent LCMV infections, induced by infecting adult mice with high doses of widely disseminating virus, depicts an epitope-specificity-based functional exhaustion or complete deletion of T cells. Prior to deletion, T cells lose functions in a prescribed order, as depicted for GP33-specific T cells. NP396-specific T cells will also lose function, but depicted here is their propensity to be completely eliminated, presumably by apoptotic mechanisms, which are, in part, controlled by Fas/FasL and TNFα.