title: Fc epsilon receptor, a specific differentiation marker transiently expressed on mature B cells before isotype switching.
abstract: The expression of Fc epsilon R on human lymphocytes was studied with the anti-Fc epsilon R mAbs. Fc epsilon R was expressed on most mu+,delta+ circulating B cells, whereas T cells did not express Fc epsilon R even in patients with hyper-IgE syndrome. B cells with gamma, alpha, or epsilon phenotype did not express Fc epsilon R, moreover its expression could not be induced, suggesting that the Fc epsilon R expression was correlated with isotype switching. mu+delta+ B cells in bone marrow did not express Fc epsilon R, but PHA-sup (supernatant from PHA-stimulated cell cultures) could induce its expression, and the addition of IgE augmented this induction. Recombinant IL-2, IL-1, IFN-gamma or -beta, or purified B cell differentiation factor (BSF-2 B cell-stimulatory factor 2) could not induce Fc epsilon R expression in bone marrow B cells. IFN-gamma inhibited the Fc epsilon R expression induced by PHA-sup, suggesting that the human counterpart of BSF-1 may be responsible for Fc epsilon R expression in bone marrow B cells. B cells from patients with common variable immunodeficiency and ataxia telangiectasia did not express Fc epsilon R, but PHA-sup could induce its expression, indicating that circulating B cells of these patients are at a differentiation stage similar to B cells in bone marrow. The study showed that Fc epsilon R is a B cell-specific differentiation marker, the expression of which is restricted to a defined stage of B cell differentiation.
mesh_terms: D001402:B-Lymphocytes / Q000032:analysis* / Q000276:immunology; D001853:Bone Marrow / Q000032:analysis; D002454:Cell Differentiation; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007132:Immunoglobulin Isotypes / Q000032:analysis*; D007153:Immunologic Deficiency Syndromes / Q000378:metabolism; D008222:Lymphokines / Q000494:pharmacology; D014066:Palatine Tonsil / Q000032:analysis; D010835:Phytohemagglutinins / Q000494:pharmacology; D011961:Receptors, Fc / Q000032:analysis* / Q000096:biosynthesis; D017455:Receptors, IgE
chemical_list: D007132:Immunoglobulin Isotypes; D008222:Lymphokines; D010835:Phytohemagglutinins; D011961:Receptors, Fc; D017455:Receptors, IgE; D007073:Immunoglobulin E