In vitro modulation of protective antibody responses by estrogen, progesterone and interleukin-6.
OBJECTIVE
We have previously demonstrated that the addition of placental interleukin-6 (IL-6) to murine hybridomas increased asymmetric antibody synthesis. Here we analyze whether progesterone (Pg) and estrogen (E2) affect asymmetric antibody synthesis by modulating IL-6 production in hybridoma cells.


METHODS
Hybridoma 112D5 B cells were cultured with E2, Pg or recombinant IL-6. Cell proliferation was assessed by 3H-thymidine incorporation, and asymmetric antibodies were measured in culture supernatants by Con A fixation and enzyme-linked immunusorbant assay (ELISA). E2 and Pg-receptors (ER and PR) were evaluated in whole cell extracts by Western blot. IL-6 was measured in culture supernatants by ELISA.


RESULTS
112D5 expressed both PR and ER, which were differentially regulated. At 48 hr, Pg and E2 slightly decreased cell proliferation whereas IL-6 did not. As well as IL-6, 10(-10) M Pg but not E2 induced asymmetric antibody production. Interestingly, Pg at 10(-6) M decreased asymmetric antibody synthesis by hybridoma cells. Finally, mainly Pg but also E2 increased IL-6 synthesis, although IL-6 levels did not correlate with asymmetric antibodies synthesized in the presence of E2 or Pg.


CONCLUSIONS
In cells expressing both ER and PR, we could demonstrate that steroids participate in humoral immune responses by modulating asymmetric antibody synthesis. IL-6 proved to be only partially involved. Other possible mechanisms involved in the effect of Pg on blocking antibody responses and their contribution to a successful pregnancy are discussed in the paper.
Canellada
Andrea
A
Instituto de Estudios de la Inmunidad Humoral-Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad de Buenos Aires, Buenos Aires, Argentina. acanell@ffyb.uba.ar
Blois
Sandra
S
Gentile
Teresa
T
Margni Idehu
Ricardo A
RA
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D004967:Estrogens / Q000276:immunology* / Q000494:pharmacology; D006825:Hybridomas / Q000187:drug effects / Q000276:immunology; D066298:In Vitro Techniques; D015850:Interleukin-6 / Q000276:immunology*; D051379:Mice; D011374:Progesterone / Q000276:immunology* / Q000494:pharmacology; D011960:Receptors, Estrogen / Q000096:biosynthesis / Q000276:immunology; D011980:Receptors, Progesterone / Q000096:biosynthesis / Q000276:immunology
D004967:Estrogens; D015850:Interleukin-6; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D011374:Progesterone