Human peripheral lymphocytes bearing surface immunoglobulin do not have readily detectable Fc receptors

The question of whether human peripheral B lymphocytes have Fc receptors was examined directly by double-label immunofluorescent techniques utilizing assays for detection of Fc receptors, surface immunoglobulin, and complement receptors. Fc receptors were detected by indirect immunofluorescence after incubation with soluble antigen-antibody complexes. Complement receptors were detected by the binding of fluoresceinated bacteria coated with complement. It was demonstrated that most surface immunoglobulin-bearing, complement-receptor positive lymphocytes did not bind soluble antigen-antibody complexes. Conversely, most cells which readily bound soluble complexes did not have surface immunoglobulin or complement receptors. Therefore, most peripheral B lymphocytes do not have easily detectable Fc receptors and most Fc receptor-bearing lymphocytes do not have B cell markers.