FIG. 2.

Ex vivo assessment of lytic function of infiltrating T cells in the CNS from BeAn-infected C57BL/6 mice against target cells loaded with the class I binding peptides. (A) The peptides capable of binding to H-2^b class I molecules were loaded in RMA-S target cells, and specific cytolysis by CNS-infiltrating T cells from virus-infected mice (8 days postinfection) was determined at different E:T ratios. VP2_121-130, which is identical to the previously reported DA virus epitope, was able to sensitize RMA-S cells for lysis and likely represents the minimal epitope within VP2_{111-130/121-140}. (B) To identify potential subdominant CTL epitopes, cytotoxicity at a higher E:T ratio (80:1) was examined (left panel). The right panel shows cytolytic activity at both high and low E:T ratios. Low but significant levels (>5% or 2 SD above background) of cytolysis were observed with target cells loaded with two additional peptides (VP2_161-180 and VP3_101-120). Spontaneous release was less than 10%. Data are representative of multiple (>5) experiments.