FIG. 6.
Effect of TNFR deficiency on the expansion of CD4 T cells during a chronic LCMV infection. Groups of +/+, p55−/−, p75−/−, and DKO mice were infected with LCMV-clone 13, and CD4 T-cell responses were examined 8 days later. (A) On the eighth day after infection, splenocytes were stained with anti-CD4 and anti-CD44 antibodies and the numbers of naive (CD44lo) and activated (CD44hi) CD4 T cells were determined by flow cytometry. (B) Eight days after infection, splenocytes were stimulated in vitro with MHC-II-restricted epitope peptide GP61-80, and the number of IFN-γ-producing CD4 T cells was determined by intracellular staining and flow cytometry. Data are the means of three to nine mice per group ± the standard deviation.