Private specificities of CD8 T cell responses control patterns of heterologous immunity

Kim, Sung-Kwon; Cornberg, Markus; Wang, Xiaoting Z.; Chen, Hong D.; Selin, Liisa K.; Welsh, Raymond M.

All the experiments in this regard are summarized in Table II, where the "ϩ" designates situations where Ͼ50% of the epitope-specific T cells lack the CSFE label (Table II) . In nearly every case, all the recipient mice from an individual donor had similar expansions of epitope-specific T cells, but the patterns differed from donor to donor. In some cases, there were no responses to any of the tested epitopes. Table II also reinforces the data from Table I showing that T cell responses to NP205 and to GP33/34 are the most frequent. These data indicate that the random stochastic process generating the primary LCMV-specific T cell response from very low frequency epitope-specific naive T cell precursors is less of a factor when the heterologous virus stimulates putative cross-reactive T cells from a much higher frequency of memory T cells, which presumably get distributed in sufficient frequencies between recipient mice. This also indicates that the patterns of heterologous T cell responses are not random but instead are predetermined by the individual private specificities of the T cell repertoire.