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.