MyD88 is not required for the development and maintenance of memory T cells after LCMV infection. (A) The frequency of tetramer-specific CD8 T cells in the blood of cKO and cHet mice was determined 8 days after LCMV infection. (B) cKO and cHet mice were treated with tamoxifen 10 days after LCMV infection, and the frequency of YFP⁺ cells was measured in blood lymphocytes by serial bleeds. (C) The frequency of H2-D^b-gp33–specific (left panel) and H2-D^b-np396–specific (right panel) cells within YFP⁺ blood lymphocytes of cKO and cHet mice was determined by tetramer staining. Data represent the means ± SD of at least 8 mice. (D) The frequency of H2-D^b-gp33–specific cells within the YFP⁺ CD8 T cells from the indicated tissues of cKO and cHet mice was assessed by tetramer staining 60 days after infection. (E) The expression of the indicated phenotypic markers was determined on gated gp33-specific YFP⁺ cells from the spleens of cKO and cHet mice 60 days after infection.