FIG. 5.

In vitro RSV-specific, MHC class I-restricted cytolytic activity of primary PMC isolated on days 7, 9, and 12 after administration of wt RSV, RSV/IL-4, or placebo and 6 days (day 33) following the challenge on day 27 with wt RSV (the mock control was included in the challenge). ⁵¹Cr-labeled P815 cells that had been incubated with 1 μM of the RSV M2-1 epitope peptide were used as the target. PMC from four mice per group for wt RSV and RSV/IL-4 or from one or two mice for mock infection were pooled, and the cytolytic activity was determined by incubation with target cells followed by the quantitation of released ⁵¹Cr. The ⁵¹Cr release from target cells without peptide was subtracted from that with the peptide. E:T ratio, effector/target ratio.