Immunosuppressive effect of early pregnancy factor on early expression of cell surface membrane IgG.
We have adopted a new assay to investigate the influence of early pregnancy factor (EPF) on the modulation of lymphocyte activity. Lymphocytes were attached to the plastic surfaces of microplates in serum-free medium in the presence of Sepharose-Con A. After 2-3 days incubation with EPF, and ELISA assay was used to detect the expression of surface membrane IgG (smIgG); this was done in the same microplates used for the culture, thus avoiding cell manipulation. Using only a few picograms of EPF a significant inhibition (in the range 26-40%) was obtained. The variation in the inhibition observed was mainly due to the different sources of lymphocytes used. Unrelated proteins and hormones, tested at the same concentration as EPF, did not show any inhibitory activity. Using the F(ab)2 fragment of anti-human IgG instead of the whole molecule the same levels of inhibition were obtained, suggesting that the observed inhibition by EPF was not due to a non-specific interaction between the anti-human IgG and the Fc receptors on the cell. Such inhibitory activity detected in vitro by this method provides additional support for a suppressive role for EPF during pregnancy.
D000328:Adult; D000469:Alkaline Phosphatase; D000906:Antibodies; D000954:Antigens, Surface / Q000276:immunology*; D002478:Cells, Cultured; D018835:Chaperonin 10; D003208:Concanavalin A / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D007108:Immune Tolerance / Q000187:drug effects*; D007074:Immunoglobulin G / Q000276:immunology*; D007166:Immunosuppressive Agents / Q000276:immunology*; D008214:Lymphocytes / Q000276:immunology*; D010455:Peptides; D011257:Pregnancy Proteins; D012685:Sepharose / Q000494:pharmacology; D013491:Suppressor Factors, Immunologic
D000906:Antibodies; D000954:Antigens, Surface; D018835:Chaperonin 10; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents; D010455:Peptides; D011257:Pregnancy Proteins; D013491:Suppressor Factors, Immunologic; C025124:early pregnancy factor; D003208:Concanavalin A; D012685:Sepharose; D000469:Alkaline Phosphatase