Functional characterization of human B cells carrying the lymphocyte large sialoglycoprotein gp150.
Human B cell-enriched populations were prepared from buffy coats of healthy donors. By means of affinity chromatography, the B cells were separated into two fractions, one enriched in and the other depleted of cells expressing gp150, the large sialoglycoprotein of lymphocytes. In the presence of autologous T cells, monocytes and pokeweed mitogen B cell populations enriched for gp150+ cells gave rise to significantly more plasma cells (cIg+ cells) and secreted significantly more IgG than gp150-depleted populations. In contrast, more or an equal amount of IgM was secreted in cultures containing gp150-depleted cells. The differences between the fractions could not be ascribed to uneven distribution of T3+ cells, OKM1+ cells or B1+ (CD20) cells. However, the gp150-enriched population contained significantly more B2+ (CD21) cells than the gp150-depleted population. These results suggest that the gp150+ B cells differ from gp150- B cells, not only in their responsiveness to T cell differentiation signals but also in their commitment to Ig heavy chain isotype secretion.
D000954:Antigens, Surface / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology*; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism; D008213:Lymphocyte Activation; D012795:Sialoglycoproteins / Q000032:analysis* / Q000276:immunology; D013154:Spleen / Q000276:immunology
D000954:Antigens, Surface; D007136:Immunoglobulins; D012795:Sialoglycoproteins