Surface-Bound Immunoglobulin on Lymphocytes from Normal and Immunodeficient Humans

By means of immunofluorescence technique, lymphocytes with surface-bound immunoglobulin were detected in the blood of normal humans F(ab')2, IgM, IgG, IgA, the four IgG subclasses, and the Gm markers Gm(f) and Gm(Z) were demonstrated on cells. IgM was the dominating class, and IgG2 the dominating IgG subclass. The data suggest that the Ig on any one cell belongs to a single class and IgG subclass. Very few lymphocytes stained for antigens on the C-terminal half of ihe IgG molecule. Ig-positive lymphocytes were also demonstrated in cord blood and in spleen cell suspensions. An almost total lack of Ig-positive lymphocytes was demonstrated in the blood of 8 patients with severe hypogammaglobulinemia. The Ig-positive lymphocytes are thought to be analogous to B-lymphocytes in other species.