MONOCLONAL-ANTIBODY DEFINED FUNCTIONAL EPITOPES ON THE ADHESION-PROMOTING GLYCOPROTEIN COMPLEX (CDW18) OF HUMAN-NEUTROPHILS

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  • 1 April 1986
    • journal article
    • research article
    • Vol. 67  (4) , 1007-1013
Abstract
We have evaluated the functional and immunochemical activities of three monoclonal antibodies (MoAbs) minimally reactive with adherence-defective neutrophils (PMN) from a patient with recurrent bacterial infections. In studies with normal PMN, MoAbs OKM1 and 60.1 both precipitate the same 165 kd .alpha.-subunit (.alpha.M) within an .alpha.-.beta. heterodimer complex (CD11). The CD11 complex is part of a larger complex composed of four glycoproteins (CDw18) precipitated by MoAb 70.3, with properties suggesting that the CDw18 complex is equivalent to the Mac-1, LFA-1, p150, 95 glycoprotein family implicated in adherence-dependent leukocyte functions. PMN aherence to endothelium, spreading on surfaces, aggregation, and phagocytosis of zymosan particles were all inhibited in a dose-dependent fashion by MoAb 60.1 (analogous to previous studies with MoAb 60.3) while MoAb OKM1 had no effect. These findings unify previously disparate observations and suggest that a functionally active site on the adherence promoting glycoprotein complexes CD11 and CDw18 is distant from the .alpha.M epitope recognized by MoAb OKM1 but closely associated with the .alpha.M epitope recognized by MoAb 60.1 and the .beta.-epitope (or epitope created by alpha-beta quarternary structure) recognized by MoAb 60.3.