Hathcock K S, Laszlo G, Dickler H B, Sharrow S O, Johnson P, Trowbridge I S, Hodes R J
Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
J Immunol. 1992 Jan 1;148(1):19-28.
A mAb (I/24) has been generated that is specific for a determinant on mouse CD45 molecules. Reactivity of this mAb with a panel of CD45 transfected cell lines demonstrated that the determinant recognized is dependent upon expression of one or more CD45 variable exons and that exon C is sufficient for its expression. The exon C-specific epitope detected by I/24 is expressed at high density on essentially all B lymphocytes and at an intermediate density on the vast majority of CD8+ splenic T cells. Two distinct subpopulations of CD4+ splenic T cells were detected, a minor subpopulation that expresses this exon determinant at high density and a major subpopulation that expresses it at a much lower density. This first identification of a CD45RC-specific reagent allowed a comparison of the expression of exon A-, exon B-, and exon C-specific determinants on peripheral and thymic lymphoid populations. When splenic lymphocytes were analyzed for expression of CD45RA (reactive with mAb 14.8), CD45RB (reactive with mAb 23G2 or mAb 16.A), and CD45RC (reactive with mAb I/24) determinants, it was found that each of these CD45 determinants had a distinct pattern of expression on CD4+ and CD8+ T cells and B cells. CD45RB and RC epitopes were also detected at high density on a small proportion (0.7 to 4.1%) of thymocytes. Both CD45RB and RC epitopes were found predominantly on CD4-CD8- and CD4-CD8+ thymocytes but were also found on small numbers of CD4+CD8+ and CD4+CD8- cells. The population of thymocytes that expressed CD45RB and CD45RC determinants displayed a novel TCR CD3 phenotype characterized by a level of expression that was intermediate between that seen in the larger CD3 bright and CD3 dull populations of thymocytes.
已产生一种针对小鼠CD45分子上一个决定簇的单克隆抗体（I/24）。该单克隆抗体与一组CD45转染细胞系的反应性表明，所识别的决定簇依赖于一个或多个CD45可变外显子的表达，并且外显子C足以使其表达。I/24检测到的外显子C特异性表位在基本上所有B淋巴细胞上高密度表达，在绝大多数CD8+脾T细胞上中等密度表达。检测到CD4+脾T细胞有两个不同的亚群，一个小亚群高密度表达该外显子决定簇，一个大亚群以低得多的密度表达。首次鉴定出CD45RC特异性试剂后，得以比较外周和胸腺淋巴群体中外显子A、外显子B和外显子C特异性决定簇的表达情况。当分析脾淋巴细胞中CD45RA（与单克隆抗体14.8反应）、CD45RB（与单克隆抗体23G2或单克隆抗体16.A反应）和CD45RC（与单克隆抗体I/24反应）决定簇的表达时，发现这些CD45决定簇在CD4+和CD8+T细胞及B细胞上各有独特的表达模式。在一小部分（0.7%至4.1%）胸腺细胞上也检测到高密度的CD45RB和RC表位。CD45RB和RC表位主要见于CD4-CD8-和CD4-CD8+胸腺细胞，但也见于少量CD4+CD8+和CD4+CD8-细胞。表达CD45RB和CD45RC决定簇的胸腺细胞群体表现出一种新的TCR CD3表型，其表达水平介于较大的CD3明亮和CD3暗淡胸腺细胞群体之间。
