ASSOCIATION CONSTANTS OF ANTIHAPTEN MONOCLONAL IGG1 WITH MOUSE FC-GAMMA-RII IN THE PRESENCE AND ABSENCE OF HAPTEN

The binding of five different mouse monoclonal anti-dinitrophenyl (DNP ) IgG1 monomers, in the presence and absence of DNP-glycine, to Fcgamm aRII on the mouse macrophage-like cell line J774 has been investigated . Membrane association constants were estimated using a competitive ra dioimmunoassay in which the ability of the IgG1 monomers to block the binding of I-125-labelled Fabs of the anti-FcgammaRII monoclonal antib ody 2.4G2 was monitored. The IgG1-FcgammaRII association constants ran ged from (8 +/-1) x 10(4) M-1 to (6 +/- 2) x 10(5) M-1. No large diffe rences in the IgG1-FcgammaRII association constants were measured for different IgG1 antibodies or for any single IgG1 antibody in the prese nce and absence of DNP-glycine.