FIG. 3.

Characterization of RSV-specific pulmonary MHC class I-restricted T cells following infection with wt RSV or RSV/IL-4 or mock infection, based on staining with antibodies to CD8 and an MHC class I tetramer loaded with an RSV peptide epitope. (A) Tetramer-positive CD8⁺ cells as a percentage of total PMC (in addition to the main panel, the data for days 4 and 5 are shown in a separate panel with a larger scale); (B) CD8⁺ cells as a percentage of total PMC; (C) tetramer-positive CD8⁺ cells as a percentage of total CD8⁺ cells. Each cell population is expressed as the mean of the percentage of total pulmonary mononuclear cells (PMC), with the standard error, based on four to six mice per group per day for wt RSV or RSV/IL-4 and one to three mice for the mock infection group. The samples were analyzed on days 4, 5, 7, 9, 12, and 63 after the primary infection or 6 days (day 33) following the challenge with wt RSV performed on day 27 (the mock control was included in the challenge). When the difference between the wt RSV and RSV/IL-4 groups is statistically significant (P < 0.05), the P value is indicated above the bars. The experiment was performed two times that resulted in similar data, and the results of a single representative experiment are shown. (D) Examples of primary flow cytometry data from individual mice on day 9 following primary infection with wt RSV or RSV/IL-4 or mock infection. Each cell population is expressed as the mean of the percentage of the total PMC. R1, tetramer-positive CD8⁺ cells; R2, tetramer-negative CD8⁺ cells.