Inhibition of Human Lymphoblastoid Cell Line Proliferation by Ascites Fluids from Ovarian Cancer Patients1

Ascitic fluids from ovarian cancer patients which contained a component (lymphocyte-inhibitory activity) that inhibited the blastogenic responses of normal lymphocytes were tested for their effect on established lymphoblastoid cell lines. These ascites fluids inhibited proliferation as measured by [3H]thymidine uptake and cell growth in vitro of two different B(SB and IM-1) and two different T(MSB and CEM) lymphoblastoid cell lines but were not cytotoxic. No difference in the sensitivity of Tand B-lymphoblastoid cell lines to the active component in the ascites fluids could be demonstrated. In contrast, estab lished nonlymphoid cell lines (HEp-2, oligodendroglioma, and bladder tumor cell lines) were unaffected by the ascites fluids. Two different preparations of partially purified lymphocyte in hibitory activity from these ascites fluids also inhibited lympho blastoid cell line proliferation. In addition, both Band T-lymphoblastoid cell lines absorbed and/or metabolized the lym phocyte-inhibitory activity at 37° but not at 4°. These data suggest that the inhibition of lymphoblastoid cell line prolifera tion and the inhibition of the blastogenic responses of normal lymphocytes by the ascites fluids are attributable to the same or similar factors.