FIG. 3.
RSV-induced immunosuppression is dependent on time, dose, and live virus. (A and B) Time and dose dependency of RSV-induced immunosuppression of CMV antigen-stimulated proliferation. MDDC were exposed to CMV antigen (vol/vol = 1:100) and RSV (multiplicity of infection [MOI] of 0, 0.4, 1, 2.5, 6.25, 8, and 10) for 4 h before incubation with autologous lymphocytes. Cells were pulsed with [3H]thymidine at different time points for proliferation assay. The results, expressed as mean cpm ± SD, are from one representative experiment of three. (A) Only MOI 0, 1, 2.5, and 6.25 are shown for clarity. (B) Proliferation on day 5 of each experimental condition showing dose dependency at that time point. (C) Only live RSV induces immunosuppression. MDDC were incubated with live RSV or UV-RSV, each at an MOI of 1, or an equal volume of sucrose buffer for 4 h (mock), washed, and incubated with SEB-stimulated autologous purified CD4 T cells for 4 days before harvest on day 5 for [3H]thymidine uptake assay. The bar indicates the median of data from 15 donors.