Frequency of RSV-specific Th2-type CD4 and CD8 T cells and protection. BALB/c mice were immunized subcutaneously with AdNull (1010 pu/mouse), AdF.RGD (1010 pu/mouse) or FIRSV (105 pfu) A, B. Ten days following immunization spleen CD4 and CD8 T cells were cultured with splenic DC pulsed with UV-inactivated RSV (105 pu/ml) for 48 h. RSV-specific cytokine response were determined by ELISPOT assay. A. RSV-specific IL-4 production in CD4 T cells. B. RSV-specific IFN-γ production in CD8 T cells. C. RSV titer in the lungs of mice challenged by intranasal administration of RSV (106 cfu) 4 wk after immunization. Data represent mean ± SD of 5 animals/group from one of two independent experiments. *** and ** denote significance of p < 0.001 and p < 0.01, respectively.