ABSTRACT
PROBLEM: To evaluate the effect of rat placental culture supernatants (PS) on spontaneous, mitogen- and alloantigen-induced lymphoproliferation, antibody synthesis regulation, and symmetric/asymmetric antibody ratio. METHOD OF STUDY: The effect of PS was determined: (a) on cell proliferation of murine hybridoma cells and on spontaneous or ConA-induced proliferation of murine and rat splenocytes by thymidine incorporation; (b) on rat or mouse cell-mediated cytotoxicity (CMC) by 51Cr release; and (c) on antibody synthesis by enzyme-linked immunoadsorbent assay (ELISA). RESULTS: With 20% PS, hybridoma cell inhibition was 37% and that of splenocytes up to 60%, whereas it was 75 and 43%, respectively, in the presence of ConA. Despite marked cell death, hybridoma proliferation index increased significantly. There was a drop in total antidinitrophenylated (DNP) immunoglobulin G1 (IgG1) antibody production and an increase in asymmetric antibody percentage, correlating with placental supernatant concentration. CONCLUSIONS: Rat placental culture supernatants inhibit cell proliferation in all cases, diminish total antibody production, and increase the percentage of asymmetric antibodies by the hybridoma, and they increase antibody production by rat splenocytes.
Subject(s)
Antibody Formation , Immunity, Cellular , Placenta/immunology , Animals , Culture Techniques , Cytotoxicity, Immunologic , Female , Hybridomas/cytology , Hybridomas/immunology , Lymphocyte Activation , Lymphocyte Culture Test, Mixed , Male , Mice , Mice, Inbred BALB C , Pregnancy , Rats , Rats, Inbred F344 , Rats, Wistar , Spleen/cytology , Spleen/immunologyABSTRACT
PROBLEM: To investigate how the factors secreted by human placenta modify the quality and the quantity of the antibody produced by the hybridoma as well as its cellular proliferation. METHOD: Supernatants of cultures of human placenta (PS) were added to a mouse IgG1 hybridoma culture producing anti-DNP antibodies. The quantity of monoclonal antibody produced, the nature of these antibodies and the proliferation of the hybridoma cells were studied. RESULT: It was found that PS augmented by 40-50% the quantity of total antibody produced, increased the proportion of asymmetric (blocking) antibodies from 15% to 30%, and diminished the cellular proliferation, as measured by 3H-thymidine incorporation. CONCLUSION: These results, together with other similar observations already described in human, rat and mouse pregnancies, suggest that secretory factors produced by the placenta do modify the immune response of the mother against paternal antigens and participate in the mechanisms that make possible the survival of the allogenic fetus.
