Murine embryonal carcinoma cells: universal targets for mammalian NK cells?

Natural killer (NK) cells from mice lyse murine teratocarcinoma stem cells in accordance with their appropriate cellular, genetic and interferon inducible features. In addition, rat and human putative NK cells were found to exhibit cytotoxicity of these embryonal carcinoma stem cells. By contrast, endodermal cells derived from such stem cells, either as cell lines or by recent induction with retinoic acid, were relatively resistant to effectors from all three mammalian species tested. Attempts to elicit a murine T-cell response to embryonal carcinoma by secondary in vitro stimulation failed. As previously shown, T killers directed to H-2 determinants were unable to lyse the MHC lacking embryonal carcinoma cells. The use of lectin "glues", a procedure supposedly capable of revealing the total cytotoxic. T-cell potential regardless of specificity, also failed to elicit lysis of these target cells. We have therefore failed to find evidence for T-cell recognition or lysis of embryonal carcinoma while NK cells from different species seemingly regard these latter cells as "universal" targets.