Three distinct antigen systems on human B cell subpopulations as defined by monoclonal antibodies.
Three distinct antigen systems on human B cell subpopulations as defined by monoclonal antibodies.
复制标题
由单克隆抗体定义的人类 B 细胞亚群的三种不同抗原系统。
作者：
T. Takami;Y. Ishii;H. Yuasa;K. Kikuchi
用Tb1-2C3、Tb1-2B3和Tb1-3c1单抗分别鉴定了人B细胞亚群表达的三个新的抗原系统(L22、L23和L24)。L22在人淋巴组织和外周血中的一小部分B细胞亚群上表达。这些与L22相关的B细胞是静息小B细胞，主要分布在淋巴滤泡的套层带，其中大部分细胞的细胞膜上也表达IgM和IGD。除B细胞型慢性淋巴细胞白血病和毛细胞白血病外，所有培养的造血细胞系包括B细胞来源的细胞系以及所有人类B细胞恶性肿瘤都不存在该抗原。另一方面，L23和L24存在于血液和淋巴组织中约三分之二的B细胞上。这些L23和L24抗原主要表达在淋巴滤泡外套膜带的小淋巴细胞上，在淋巴生发中心内的大母细胞上表达较少。L23和L24和L22一样，在分化为抗体分泌细胞的过程中似乎从B细胞中消失了，因为它们在正常和肿瘤浆细胞上不表达。观察到L23和L24在商陆丝裂原激活和Epstein-Barr病毒转化的B细胞上很少或根本不表达，这进一步证实了这一点，并且在一些被认为对应于B细胞发育后期的B细胞恶性肿瘤中没有表达。成熟粒细胞和单核细胞表达L23，但不表达L22和L24；人胸腺和T细胞不表达L22、L23和L24。免疫沉淀研究表明，L23和L24是由单一糖蛋白组成的不同分子物种。分别为20.5万和14.5万。L22抗原目前正在研究中。
Three novel antigen systems (L22, L23, and L24) expressed on human B cell subpopulations were identified by using TB1-2C3, TB1-2B3, and TB1-3C1 monoclonal antibodies, respectively. L22 was expressed on a minor subpopulation of B cells in human lymphoid tissues and in the peripheral blood. These B cells associated with L22 were resting small B cells mainly located in the mantle zone of lymphoid follicles, most of which also expressed IgM and IgD on their cell membrane. This antigen was absent from all cultured hemopoietic cell lines including B cell-derived cell lines as well as from all human B cell malignancies, except for B cell-type chronic lymphocytic leukemia and hairy cell leukemia. L23 and L24, on the other hand, existed on approximately two-third of B cells in blood and lymphoid tissues. These L23 and L24 antigens were expressed largely on small lymphocytes located in the mantle zone of lymphoid follicles and to a lesser extent on large blastic cells within lymphoid germinal centers. L23 and L24, like L22, seem to disappear from B cells during their differentiation into antibody-secreting cells, because they were not expressed on normal and neo-plastic plasma cells. This is additionally confirmed by the observation that L23 and L24 were expressed little or not at all on pokeweed mitogen-activated and Epstein-Barr virus-transformed B cells, and were absent from some of B cell malignancies that have been thought to correspond to the later stages of B cell development. Although L23, but not L22 and L24, was faintly expressed on mature granulocytes and monocytes, none of L22, L23, or L24 existed on human thymus and T cells. Immunoprecipitation studies showed that L23 and L24 were different molecular species consisting of a single glycoprotein with m.w. of 205,000 and 145,000, respectively. L22 antigen is presently under study.