FIG. 5.

In vivo depletion of T-cell subsets. Mice were immunized twice with 10⁵ TCID₅₀ of RSV-A, 20 μg of BBG2Na or 20 μg of PBS in 20% alum at a 2-week interval. After bleeding they were either untreated (0) or depleted of CD4⁺ or/and CD8⁺ T cells by i.p. injections of anti-CD4 or/and anti-CD8 Abs, respectively, twice before RSV-A challenge and twice thereafter. Mean ± SD RSV-A titers of lung (A) and NTL (B) were determined for groups of seven animals at day 5 postchallenge. ∗, P < 0.05 calculated by t test using the null hypothesis.