COMPARISON OF IMMUNOSUPPRESSIVE PROPERTIES OF HYDATIDIFORM MOLE DECIDUA AND TROPHOBLAST EXTRACTS

PROBLEM: The immunologic privilege afforded the fetus relies upon immu noregulation within the maternal-fetal interface. Trophoblast and deci dua-derived immunoregulatory factors enforce this privilege by locally suppressing maternal responses to trophoblast antigens. The relative contribution of trophoblast or decidua immunosuppressive factors to pr egnancy immunotolerance are not well characterized. The purpose of thi s study was to compare the suppressive effects of hydatidiform mole tr ophoblast and decidua extracts on interleukin-2-dependent proliferatio n. METHOD: Tissue extracts were prepared from hydatidiform more tropho blast and decidua following uterine evacuation. Samples were submitted to interleukin-2-dependent and independent cell proliferation assays. RESULTS: Hydatidiform mole trophoblast extract significantly (P < 0.0 5) suppressed interleukin-2-dependent proliferation bur did not affect interleukin-2-independent cell proliferation. In contrast, molar deci dua extract suppressed both cell lines. CONCLUSIONS: Human hydatidifor m male trophoblast contains factor(s) that specifically abrogate inter leukin-2-dependent clonal expansion of murine cytotoxic T-cells. In co ntrast, extracts of molar decidua suppressed both interleukin-2-depend ent and -independent responses. This indicates that the trophoblast an tagonizes critical interleukin-2-mediated immunologic responses, but t hat the decidua uses nonspecific antiproliferative mechanisms for immu noregulation.