Normal human serum restores the expression of Fc gamma receptors in immune complex-blocked human mononuclear cells.
A progressive inhibition of both antibody-dependent cellular cytotoxicity (ADCC) and Fc gamma R expression was observed when peripheral blood mononuclear cells (PBMC) were incubated with soluble immune complexes (IC) at 37 degrees. Treatment of these IC-blocked PBMC with normal human serum (NHS) reversed both effects and increased the release of attached IC from the cell surface when compared to heat-inactivated serum (HI-NHS) or culture medium (TCM) treatments. Immunofluorescence studies demonstrated a redistribution of IC, predominantly in the form of caps in IC-blocked cells treated with HI-NHS (56%) or TCM (51%). However, when these IC-blocked cells were treated with NHS, only 11% of them showed caps redistribution. We propose that NHS regulation of Fc gamma R expression may be a physiological way of modulating the different immunological events triggered by IC.
D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity; D000936:Antigen-Antibody Complex / Q000276:immunology*; D001769:Blood; D003167:Complement Activation; D005455:Fluorescent Antibody Technique; D006358:Hot Temperature; D066298:In Vitro Techniques; D009000:Monocytes / Q000276:immunology*; D011961:Receptors, Fc / Q000032:analysis*; D017452:Receptors, IgG
D000936:Antigen-Antibody Complex; D011961:Receptors, Fc; D017452:Receptors, IgG