Birkeland M L, Metlay J, Sanders V M, Fernandez-Botran R, Vitetta E S, Steinman R M, Puré E
Rockefeller University Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235.
J Mol Cell Immunol. 1988;4(2):71-85.
In the course of isolating hybridomas from rats that had been immunized with anti-Ig activated murine B lymphoblasts, we have identified three new mAb reactive with the T200 or leukocyte common antigen family (CD45). One, MB4B4, reacts with T200 on all leukocytes, and immunoprecipitates all the molecules that are recognized by an existing mAb to this family. Two others, MB23G2 and MB15C11, react with a subset of T200 molecules that has a unique tissue and cellular distribution. By FACS analysis and by immunocytochemical labeling of tissue sections, MB23G2/15C11 bind to most, if not all, small B and T lymphocytes, but react weakly with macrophages and dendritic cells. Expression of the MB23G2/15C11 T200 epitope exhibits four distinct features on lymphocytes: 1) activation of CD4+ cells in the mixed leukocyte reaction results in a decreased expression of MB23G2/15C11, on a subset of 30-60% of the T-cell blasts; 2) of 16 T-helper clones examined, clones of the TH2 phenotype express moderate to high levels of MB23G2/15C11 (2.5-19-fold increase in median fluorescence over control) while the TH1 clones express low to moderate levels (1.2-6.4-fold increase in median fluorescence over control) of the antigen recognized by these mAb; 3) The MB23G2/15C11 mAb do not react with germinal center cells in tissue sections of spleen, lymph node, and Peyer's patches; 4) MB23G2/15C11 reacts primarily with a subset of large thymocytes localized to the medulla. Therefore, MB23G2/15C11 define a subset-restricted form of T200 (CD45R) on murine lymphocytes. The tissue distribution of this T200 associated epitope is distinct from previously defined CD45 antigens and suggests a role during several pathways of lymphocyte development.
在从用抗Ig激活的鼠B淋巴母细胞免疫的大鼠中分离杂交瘤的过程中，我们鉴定出三种与T200或白细胞共同抗原家族（CD45）反应的新单克隆抗体。一种是MB4B4，它与所有白细胞上的T200反应，并免疫沉淀该家族现有单克隆抗体所识别的所有分子。另外两种，MB23G2和MB15C11，与具有独特组织和细胞分布的T200分子亚群反应。通过流式细胞术分析和组织切片的免疫细胞化学标记，MB23G2/15C11与大多数（如果不是全部）小B淋巴细胞和T淋巴细胞结合，但与巨噬细胞和树突状细胞反应较弱。MB23G2/15C11 T200表位在淋巴细胞上表现出四个不同特征：1）混合淋巴细胞反应中CD4+细胞的激活导致30%-60%的T细胞母细胞亚群上MB23G2/15C11表达降低；2）在所检测的16个T辅助克隆中，TH2表型的克隆表达中等至高水平的MB23G2/15C11（中位荧光比对照增加2.5-19倍），而TH1克隆表达低至中等水平（中位荧光比对照增加1.2-6.4倍）的这些单克隆抗体所识别的抗原；3）MB23G2/15C11单克隆抗体不与脾脏、淋巴结和派尔集合淋巴结组织切片中的生发中心细胞反应；4）MB23G2/15C11主要与位于髓质的大胸腺细胞亚群反应。因此，MB23G2/15C11在鼠淋巴细胞上定义了一种亚群限制性形式的T200（CD45R）。这种与T200相关的表位组织分布与先前定义的CD45抗原不同，并提示其在淋巴细胞发育的几种途径中发挥作用。
