Effect of rat placental culture supernatants on cellular and humoral immune responses.
OBJECTIVE
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.


METHODS
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.
Malan Borel
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I
Instituto de Estudios de la Inmunidad Humoral (CONICET-UBA), Facultad de Farmacia y Bioquímica de la Universidad de Buenos Aires, Argentina.
Menezes Freire
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S
Canellada
A
A
Margni
R A
RA
D000818:Animals; D000917:Antibody Formation; D046508:Culture Techniques; D003602:Cytotoxicity, Immunologic; D005260:Female; D006825:Hybridomas / Q000166:cytology / Q000276:immunology; D007111:Immunity, Cellular; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010920:Placenta / Q000276:immunology*; D011247:Pregnancy; D051381:Rats; D011916:Rats, Inbred F344; D017208:Rats, Wistar; D013154:Spleen / Q000166:cytology / Q000276:immunology