Fce RECEPTOR AND ISOTYPE SWITCHING
نویسندگان
چکیده
B lymphocytes originate from pluripotent hematopoietic stem cells and differentiate into antibody-secreting cells through multistep differentiation stages, such as pre-B cells, immature B cells with surface IgM, and mature B cells with surface IgM and IgD . A number of human B cell antigens have been defined by in Abs (I-10) . However, most B cell-specific mAbs, except for antibodies against plasma cells (5) and activated B cells (9, 10), are known to recognize cells of the B lineage at a wide range of differentiation stages from pre-B cells to mature B cells . It has therefore been difficult to identify B cells at a specific differentiation stage by using such B cell-specific mAbs. Several previous studies (11-14) have shown the expression of FcER on a certain percentage (1-5%) of circulating B or T cells using the rosette method with IgE-conjugated ox red blood cells (ORBC). t Our previous study (15) with FcER-specific mAbs with several different epitope specificities showed that >50% of circulating B cells express FcER on their surface, while T cells do not display this receptor, even with T cells from patients with hyper-IgE syndrome . The discrepancy in the results may be due to the difference in the sensitivity of the assay system and the antibodies used. In the present study, the distribution of FcER+ cells was studied in various lymphoid tissues, and the results show that FcER is a B cell-specific phenotype marker, the expression of which is strictly correlated with the differentiation stage of B cells, especially with the isotype switching in B cells .
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تاریخ انتشار 2003