Affinity column purified goat anti-mouse immunoglobulin antibodies specific for the Fc portion of IgG increased an in vitro antibody response to a T-dependent antigen when T cells were limiting. Picogram amounts of specific anti-Fc antibody at culture initiation and nanogram quantities up to 3 days were required to demonstrate this effect. The demonstration of reconstitution by anti-Fc antibodies requires that the cultures be T-cell depleted and stimulated by antigen. These results support the concept that anti-Fc antibody and T cells block endogenously generated negative Fc signals.
Bibliographical noteFunding Information:
’ This work was supported by the Medical Research Council of Canada ’ To whom all correspondence should be addressed. 3 Abbreviations used: PFC, plaque-forming cells; Ig, immunoglobulin.