The expression of receptors for IgA on human monocytes and calcitriol-treated HL-60 cells.
In this study, we investigated the expression of IgA Fc receptors (FcR alpha) by human myeloid cells. By using a sensitive cytofluorometric IgA binding assay, we found that approximately 85% of peripheral blood monocytes bound IgA in an isotype-specific fashion. The HL-60 human promyelocytic leukemia cell line failed to express FcR alpha; however, treatment of HL-60 cells with the differentiating agent calcitriol induced the expression of FcR alpha on greater than 90% of these cells. Monocytes and calcitriol-treated HL-60 cells were capable of ingesting IgA-coated erythrocyte targets, suggesting that phagocytosis could be mediated through FcR alpha. The induced HL-60 cell system represents a useful model for further studies on FcR alpha expression and function.
D015703:Antigens, CD; D002117:Calcitriol / Q000494:pharmacology*; D002460:Cell Line; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism*; D009000:Monocytes / Q000276:immunology / Q000378:metabolism*; D010587:Phagocytosis / Q000187:drug effects; D011961:Receptors, Fc / Q000378:metabolism*
D015703:Antigens, CD; C036832:Fc(alpha) receptor; D007070:Immunoglobulin A; D011961:Receptors, Fc; D002117:Calcitriol