Human teratoma cells share antigens with mouse teratoma cells

The mouse teratocarcinoma cell line 402AX is known to express surface antigens[hereafter called teratoma-defined antigen(s)] shared with early mouse embryos and some other murine cell lines, as detected by an absorbed rabbit antiserum. As gauged by immunofluorescence, human teratocarcinoma cells (tera 2) following neuraminidase treatment display antigen(s) cross-reactive with mouse teratoma-defined antigens. On the human tumor cells the teratoma-defined antigen(s) is density dependent, being present on subconfluent cultures, but absent on confluent cultures. Neuraminidase-treated control subconfluent human fibroblasts are nonreactive with the antiserum. Sera from some human patients presenting with teratocarcinoma, absorbed on normal mouse tissue to remove the nonspecific hetero-anti-species antibodies, show anti-mouse teratoma reactivity by immunofluorescence and microcytotoxicity. Sera from age- and sex-matched individuals with nonteratoma tumors are nonreactive with the mouse teratoma cells. The antigenic determinant(s) detected by the human teratoma sera co-caps with H-2 antigens on the mouse mastocytoma line P815, as do the rabbit antiserum-defined teratoma antigens. These data suggest that human and mouse teratomas share common antigens, and that these antigens may be integrally related to the major histocompatibility antigens in both species.