FIG. 4.

Migrating CFSE⁺ cDC transport viral RNA to the lung-draining LN and present antigens by MHC-I and MHC-II molecules. (A) MLN cDC were harvested 72 h post-RSV infection and sorted into four populations based on CD103 expression and CFSE labeling. (B) Sorted MLN cDC (10⁴ cells/subset) were analyzed for the presence of RSV N RNA by quantitative RT-PCR. (C and D) Antigen presentation was analyzed by culturing RSV-specific CD4⁺ or CD8⁺ T-cell populations for 24 h with sorted cDC subsets isolated from the MLN 72 h after RSV infection. To enrich for CD8⁺ T cells, lung lymphocytes isolated on day 8 after primary RSV infection were depleted of CD4⁺ T cells, B cells, and NK cells. Similarly, CD4⁺ T cells were enriched by the depletion of CD8⁺ T cells, B cells, and NK cells. RSV-specific IFN-γ production was measured by ELISPOT assay. Data shown are the means of data from six individual experiments for the RT-PCR assay. For the ELISPOT assay, the mean values for five individual experiments using cDC purified from five individual mice for each experiment are shown. Error bars represent SEM (*, P < 0.05; **, P < 0.01; ns, not significant; n.d., not detected).