The adherence of human Fc receptor bearing lymphocytes to immobilized antigen—Antibody complexes I. Specificity and use as preparative separation technique

The surfaces of polystyrene tissue culture vessels were coated with antigen—antibody complexes by trinitrophenylation of an adsorbed layer of protein followed by treatment with rabbit anti-hapten antibody. A subpopulation of human peripheral blood lymphocytes bearing Fc receptors adheres to such immobilized antigen—antibody complexes. This adhesion is antibody-dependent, requires an intact antibody Fc, and can be inhibited by preincubation of the cells with antigen—antibody complexes. Used as a preparative procedure, human lymphocytes can be fractioned with good yields into a non-adherent population depleted of cells bearing easily detectable Fc receptors and of cells mediating ADCC. This non-adherent population contains a slightly greater proportion of lymphocytes bearing surface immunoglobulin and complement receptors (i.e. B cells) than the original population and is enriched for E rosette-forming cells. After removal from the antigen—antibody complex coated surface, the adherent lymphocytes retain rabbit antibody from the substrate on their surfaces. These cells do not bear surface immunoglobulin nor complement receptors, although about half form E rosettes. After 24 hours of culture, rabbit antibody is no longer detected on the cell surfaces and the cells are able to bind new antigen—antibody complexes to their Fc receptors. Although the non-adherent fraction is always depleted of cells mediating ADCC when compared to the unnseparated population, the adherent population recovered from the substrate is variable in its ADCC activity. However, if trypsin is used to remove the adherent cells, after culture this population shows enhanced ADCC activity.