Aida Y, Okada K, Amanuma H
Laboratory of Gene Technology and Safety, Tsukuba Life Science Center, Institute of Physical and Chemical Research (RIKEN), Ibaraki, Japan.
Cancer Res. 1993 Jan 15;53(2):429-37.
The phenotype and ontogeny of cells carrying the tumor-associated antigen (TAA), identified in tumors of cattle with enzootic bovine leukosis (EBL) by use of the monoclonal antibody (MAb) c143, were analyzed by flow cytometry and immunohistochemistry. The TAA recognized by the c143 MAb (c143 TAA) was mainly expressed on B-cells, macrophages, reticular cells, and a minor population of BoCD4-positive T-cells in bovine leukemia virus (BLV)-free normal cattle. When the peripheral blood mononuclear cells from normal cattle were activated in vitro, some populations of BoCD8-positive T- and non-T/non-B-cells also showed expression. Moreover, B-cells expressed the c143 TAA until the antigen was lost from cells at the final stage of B-cell differentiation, namely, the plasma cell stage. The c143 MAb-positive cells in blood of BLV-free normal cattle form heterologous subpopulations, and these cells coexpress other surface markers such as BoCD2, BoCD5, BoCD6, and B-cell-specific molecules B1 low, B1 bright, and B2. In BLV-infected cattle, the proportion of peripheral blood mononuclear cells that express the c143 TAA increased with the progression of EBL, and, in addition, BLV-infected cattle that had no lymphosarcomas showed increased proportions of c143 MAb-positive cells that coexpressed surface IgM (sIgM), BoCD5, B1 low, and B2 but not BoCD2, BoCD4, or BoCD6. Furthermore, most of the c143 MAb-positive tumors from all cattle with EBL appeared to be a monoclonal population derived from a single B-cell and to be divided into two types, c143 TAA+BoCD5+B1 low+ B2+ sIgM+ or sIgM-. Collectively, these results show that the c143 TAA is not only a useful surface marker for identification of EBL but also a marker of differentiation of lymphoid cells.
利用单克隆抗体（MAb）c143，对在地方流行性牛白血病（EBL）患牛肿瘤中鉴定出的携带肿瘤相关抗原（TAA）的细胞的表型和个体发生进行了流式细胞术和免疫组织化学分析。在无牛白血病病毒（BLV）的正常牛中，c143单克隆抗体识别的TAA（c143 TAA）主要表达于B细胞、巨噬细胞、网状细胞以及一小部分BoCD4阳性T细胞。当正常牛的外周血单个核细胞在体外被激活时，一些BoCD8阳性T细胞和非T/非B细胞群体也表现出表达。此外，B细胞在B细胞分化的最后阶段，即浆细胞阶段，在细胞失去抗原之前一直表达c143 TAA。无BLV的正常牛血液中的c143单克隆抗体阳性细胞形成异源亚群，这些细胞共表达其他表面标志物，如BoCD2、BoCD5、BoCD6以及B细胞特异性分子B1 low、B1 bright和B2。在感染BLV的牛中，表达c143 TAA的外周血单个核细胞比例随着EBL的进展而增加，此外，没有淋巴肉瘤的感染BLV的牛中，共表达表面IgM（sIgM）、BoCD5、B1 low和B2但不表达BoCD2、BoCD4或BoCD6的c143单克隆抗体阳性细胞比例增加。此外，所有患有EBL的牛的大多数c143单克隆抗体阳性肿瘤似乎是源自单个B细胞的单克隆群体，并分为两种类型，c143 TAA+BoCD5+B1 low+ B2+ sIgM+或sIgM-。总体而言，这些结果表明，c143 TAA不仅是鉴定EBL的有用表面标志物，也是淋巴细胞分化的标志物。
