Immunosuppressive activity of rhesus monkey pregnancy serum.
Normal pregnancy serum from the rhesus monkey was found to have immunosuppressive activity. Using two-way stimulation, the mixed lymphocyte response was suppressed as much as 80%. Control serum from nonpregnant females was not suppressive. The inhibiting factor was found to have the following characteristics: (1) it was nonspecific in activity; (2) it inhibited the mixed lymphocyte response 20% at in vitro concentrations of 1%; (3) it was heat stable (56 degrees C for 30 minutes) and nondialyzable; (4) it was present in both the IgM- and IgG-containing fractions of pregnancy serum; (5) it was detected in postpartum and second and third trimester serum; and (6) it was at low levels or absent from the serum of two pregnancies which terminated in unexplained stillbirths.
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D005260:Female; D005333:Fetus / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D007166:Immunosuppressive Agents / Q000097:blood*; D007959:Lymphocyte Culture Test, Mixed; D008253:Macaca mulatta; D011247:Pregnancy; D011270:Pregnancy, Animal
D007075:Immunoglobulin M; D007166:Immunosuppressive Agents