Comparative study of biological properties of proteins synthetised in vitro by murine decidua and deciduoma.

Supernatants from short-term in vitro cultures of murine decidual tissue obtained from the uteri of pregnant mice on day 8 postcoïtum (decidua, in the presence of paternal antigens) or from pseudopregnant mice (deciduoma, without any histocompatibility antigens were assessed for their regulatory activity; both statuses (physiological and experimental) can only be developed under hormonal conditions. All these supernatants possess no complement inhibitory activity, but they markedly impair the generation of cytotoxic T cells (CTL) and suppress anti-sheep red blood cell antibody response. These effects seem essentially located in a single AcA 22 fraction of 60 KD that inhibits CTL, while the plaque-forming cell response is strongly stimulated. Electrophoretic and gel filtration profiles of supernatants from cultures of decidua and deciduoma seem similar. The results suggest that the factors synthetised by decidua or deciduoma are the same and are not induced by exposure to foreign histocompatibility antigens of the fetus. According to these results, it seems likely that decidualization represents a localized general mechanism that can be induced, under a particular hormonal background, by different stimuli (trauma) rather than being a specific response to a particular signal (blastocyst).