Bell E B, Sparshott S M
Department of Cell and Structural Biology, Medical School, University of Manchester, UK.
Nature. 1990 Nov 8;348(6297):163-6. doi: 10.1038/348163a0.
T lymphocytes express multiple forms of the leukocyte common antigen CD45, transcribed by alternative usage of leukocyte-common antigen exons 4-6. Species-specific monoclonal antibodies against restricted epitopes (CD45R) of the antigen subdivide CD4 T cells into reciprocal subsets expressing either the high molecular weight isoforms CD45RA or RB or a molecule in which exons 4-6 have been spliced out (CD45R0). CD45R+ or RB+ CD4 T cells are potent in graft-versus-host reactions, and interleukin-2 related activities, whereas the CD45R0+ subset responds in vitro to recall antigens and provides help for antibody synthesis. It is unclear whether CD45R subsets derive from separate lineages, or are products of unidirectional or reversible differentiation. We show by transferring CD45R+ or CD45R- allotype-marked CD4 T cells into athymic nude rats that both subsets routinely generate cells of the opposite phenotype with a function that follows phenotype, not parentage. The recent equation of CD45R subsets as maturation stages representing 'naive' and 'memory' T cells is difficult to reconcile with this finding.
T淋巴细胞表达多种形式的白细胞共同抗原CD45，它是通过白细胞共同抗原外显子4 - 6的交替使用进行转录的。针对该抗原受限表位（CD45R）的种属特异性单克隆抗体将CD4 T细胞细分为相互对应的亚群，这些亚群分别表达高分子量同种型CD45RA或RB，或者是已剪接掉外显子4 - 6的分子（CD45R0）。CD45R +或RB + CD4 T细胞在移植物抗宿主反应以及白细胞介素 - 2相关活性方面表现活跃，而CD45R0 +亚群在体外对回忆抗原作出反应，并为抗体合成提供帮助。目前尚不清楚CD45R亚群是源自不同的谱系，还是单向或可逆分化的产物。我们通过将带有CD45R +或CD45R -同种异型标记的CD4 T细胞转移到无胸腺裸鼠体内发现，这两个亚群通常都会产生具有相反表型的细胞，其功能遵循表型而非亲本来源。最近将CD45R亚群视为代表“幼稚”和“记忆”T细胞的成熟阶段的观点难以与这一发现相协调。
