Properties of human pre- and post-implantation embryo-associated immunosuppressor factor(s).
Embryo-associated immunosuppressor factor (EASF), a factor detected by its suppressive property on the concanavalin A (ConA) stimulated lymphocyte proliferation assay, was purified from human embryo growth media of in vitro fertilized ova (pre-implantation source) and from pregnancy sera (post-implantation source) as 3 fractions, CM-1, CM-3 and CM-6, the immunosuppressive properties of which were studied. The results show that, (i) the 3 fractions of EASF from both sources suppressed ConA- and pokeweed mitogen (PWM)-induced lymphocyte proliferation, suggesting that they have suppressive effects on both T and B cells; (ii) all 3 EASFs were suppressive when added at the early phase of ConA-supplemented cultures; (iii) CM-1 of both sources were suppressive when added to PWM-supplemented cultures between 24 and 48 h; and (iv) CM-6 of both sources showed an irreversible immunosuppressive effect on PWM-induced lymphocyte proliferation, demonstrating that some similarities exist in the immunosuppressive property of EASF from the 2 sources. On the other hand, (i) CM-6 of pre- and post-implantation EASF were immunosuppressive when added to the PWM-supplemented cultures at 24-48 h and 0-16 h, respectively; and (ii) the CM-6 fraction of pregnancy sera, but not the CM-6 fraction of embryo growth media, possessed an irreversible immunosuppressive effect on ConA-supplemented cultures. This active process by which EASF affects T cell and B cell functions directly may be one of several responses by which the maternal immune response against the fetus is prevented.
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Department of Obstetrics, Gynecology and Reproductive Sciences, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
D001402:B-Lymphocytes / Q000187:drug effects; D001755:Blastocyst / Q000737:chemistry* / Q000276:immunology; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D003470:Culture Media / Q000737:chemistry; D003864:Depression, Chemical; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D008213:Lymphocyte Activation / Q000187:drug effects*; D011043:Pokeweed Mitogens; D011247:Pregnancy / Q000097:blood* / Q000276:immunology; D013491:Suppressor Factors, Immunologic / Q000302:isolation & purification* / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects
D003470:Culture Media; D011043:Pokeweed Mitogens; D013491:Suppressor Factors, Immunologic; D003208:Concanavalin A