LYMPHOCYTE RECEPTORS .1. RECEPTORS FOR FC OF IGG AND COMPLEMENT (C3B) ON IMMUNOGLOBULIN-BEARING, ANTIGEN-BINDING AND ANTIBODY-SECRETING CELLS

Abstract

Immunoglobulin(Ig)-bearing, antigen-binding and antibody-secreting [mouse] cells were investigated for the presence of membrane receptors for the Fc part of IgG and for C3b [b fragment of the 3rd complement component] on their surface. Fc and C3b receptors were detected on the surface of most Ig-bearing and of most antigen-binding cells. Fc receptors were detected on IgM antibody-secreting cells, but not on IgG-secreting cells. C3b receptors were not detected on any antibody-secreting cells. These receptors are lost from the B [bone marrow-derived] cell surface as they differentiate into antibody-secreting cells or are blocked in vivo by immune complexes or C3b.