Suppression of mitogen-induced lymphoproliferation by soluble IgG Fc receptors in retroplacental serum in normal human pregnancy.
A competitive ELISA was used to quantify soluble IgG Fc receptors (FcR) in retroplacental serum (RPS) and peripheral serum (PS) from 10 women after uncomplicated full-term deliveries. The RPS contained significantly higher amounts of soluble FcR than did PS from the same individuals. RPS suppressed phytohaemagglutinin-stimulated lymphoproliferation as compared with PS, and a positive correlation (r = 0.66) was found between the degree of suppression and the difference in soluble FcR level between RPS and PS. Absorption of sera with Sepharose 4B coupled with heat-aggregated IgG strongly reduced the immunosuppressive activity, whereas absorption with Sepharose coupled with IgG F(ab')2 fragments did not. When IgG-binding material was eluted from Sepharose beads and added to cell cultures, the immunosuppressive activity was restored. The data indicate that soluble FcR at physiological levels have immunosuppressive properties. FcR-mediated immunosuppression may be of importance for maintenance of local immunosuppression during pregnancy.
Aarli
A
A
Broegelmann Research Laboratory for Microbiology, University of Bergen, Norway.
Skeie Jensen
T
T
Ulvestad
E
E
Matre
R
R
D005260:Female; D005312:Fetal Blood / Q000166:cytology* / Q000276:immunology; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology; D007070:Immunoglobulin A / Q000097:blood; D007141:Immunoglobulin Fc Fragments / Q000378:metabolism*; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008213:Lymphocyte Activation / Q000187:drug effects*; D011247:Pregnancy / Q000097:blood*; D011961:Receptors, Fc / Q000032:analysis / Q000502:physiology*; D012995:Solubility
D007070:Immunoglobulin A; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011961:Receptors, Fc