Analysis of the xenogeneic T-cell response to murine H-2 negative embryonal carcinoma cells

Murine embryonal carcinoma cells are the stem cells of teratocarcinomas. They do not express H-2 antigens and previous reports have shown that these cells are not killed by major histocompatibility complex (MHC) restricted murine cytotoxic T cells. Here we report that effectors generated in MLCs between responders from a W3/13 enriched, NK-cell-depleted, rat spleen population, and spleen stimulators from 129 mice can lyse 129 embryonal carcinoma (EC) cells, but not CBA EC cells. A similar pattern of specific lysis of EC cells was seen with effectors generated in MLCs between rat lymph node and mouse spleen stimulators. Following priming in vivo with 129 EC cells, the frequency of cytotoxic T lymphocyte precursors against both 129 EC cells and 129 blast targets was increased when compared with the frequency found in age- and sex-matched unprimed animals. This response shows both specificity and memory and we conclude from this that it is due to rat T cells recognizing mouse xenogeneic antigens.