EFFECT OF RAT PLACENTAL CULTURE SUPERNATANTS ON CELLULAR AND HUMORAL IMMUNE-RESPONSES

PROBLEM: To evaluate the effect of rat placental culture supernatants (PS) on spontaneous, mitogen-and alloantigen-induced lymphoproliferati on, antibody synthesis regulation, and symmetric/asymmetric antibody r atio. METHOD Of STUDY: The effect of PS was determined: (a) on cell pr oliferation of murine hybridoma cells and on spontaneous or ConA-induc ed proliferation of murine and rat splenocytes by thymidine incorporat ion; (b) on rat or mouse cell-mediated cytotoxicity (CMC) by Cr-51 rel ease; and (c) on antibody synthesis by enzyme-linked immunoadsorbent a ssay (ELISA). RESULTS: With 20% PS, hybridoma cell inhibition was 37% and that of splenocytes up to 60%, whereas it was 75 and 43%, respecti vely, in the presence of ConA. Despite marked cell death, hybridoma pr oliferation index increased significantly. There was a drop in total a ntidinitrophenylated (DNP) immunoglobulin G1 (IgG1) antibody productio n and an increase in asymmetric antibody percentage, correlating with placental supernatant concentration. CONCLUSIONS: Rat placental cultur e supernatants inhibit cell proliferation in all cases, diminish total antibody production, and increase the percentage of asymmetric antibo dies by the hybridoma, and they increase antibody production by rat sp lenocytes.