IMMUNE PHENOTYPE AND CYTOTOXIC ACTIVITY OF LYMPHOCYTES FROM HUMAN TERM DECIDUA AGAINST TROPHOBLAST

Flow cytometric data were used to compare the phenotype of term decidu al lymphocytes and peripheral blood lymphocytes. Unlike peripheral blo od lymphocytes, a significant percentage of CD3(+), CD4(+), CD8(+) and CD16(+) term decidual lymphocyte populations expressed the CD69 activ ation marker. The relative proportions,of CD38 in CD3(+), CD4(+) and C D8(+) populations were more than twice as large in term decidual lymph ocytes as in peripheral blood lymphocytes. As reported for early-decid ual lymphocytes, the expression of CD38 and CD69 by term decidual lymp hocytes suggests that these cells are also regionally activated. Howev er, term decidual lymphocytes showed no spontaneous cytotoxicity again st normal trophoblast or its tumoral counterpart, JEG cells. After sti mulation with interleukin-2, these lymphocytes became cytotoxic, as di d peripheral blood lymphocytes. The relevance of this latter result to the immune control of the physiological and pathological invasion of the decidua by the trophoblast is discussed.