Figure 4.

Lytic potential of virus-immune Tc cells from spleen of wild-type and gzm-deficient mice. e/t, effector to target cell ratio. (A) Lysis of MC57 target cells by B6, gzmA^−/−, gzmB^−/−, and gzmA×B^−/− Ect-immune splenocytes from two individual mice (squares and circles) 6 and 7 days p.i. with 10⁶ PFU into the hind footpad. Targets were mock-infected (closed symbols), or infected with Ect (open symbols) for 16 h. †indicates that mouse died. (B) Splenocytes from influenza virus-primed B6, gzmA^−/−, gzmB^−/−, and gzmA×B^−/− mice (6–8 weeks previously) from two individual mice (squares and circles) were restimulated in vitro with A/WSN-infected syngeneic stimulator cells for 5 days. Effectors were tested for ⁵¹Cr release on El-4 target cells either mock-infected (closed symbols) or infected with A/WSN (open symbols). Cytotoxic assay time for A and B was 6 h. Each point constitutes the mean percentage of specific lysis of 3 separate wells with SEM never >5%. Spontaneous release was always <20%.