FIG. 3.

Direct CTL assay of lungs of RSV-infected mice day 8 after infection. (A) L1210Fas+ and L1210Fas− target cells sensitized with RSV M2 peptide were used to measure the relative contributions of perforin- and FasL-mediated killing in WT and PKO mice. ✖, uninfected mice: ●, WT effectors with L1210Fas− targets; ○, WT effectors with L1210Fas+ targets: ■, PKO effectors with L1210Fas− targets; □, PKO effectors with L1210Fas+ targets. (B) Anti-FasL antibody was used to show FasL involvement in target cell lysis using effectors from perforin-deficient mice. The effector-to-target ratio for panel B is 100:1. Data are representative of results of three independent experiments with five mice per group.