CD8+ T细胞的CD45RA+和CD45RA-亚群均包含淋巴细胞功能相关抗原-1表达水平高的细胞，这是致敏T细胞的一种表型。

Both CD45RA+ and CD45RA- subpopulations of CD8+ T cells contain cells with high levels of lymphocyte function-associated antigen-1 expression, a phenotype of primed T cells.

作者信息

Okumura M, Fujii Y, Inada K, Nakahara K, Matsuda H

机构信息

First Department of Surgery, Osaka University Medical School, Japan.

出版信息

J Immunol. 1993 Jan 15;150(2):429-37.

PMID:7678274

Abstract

Expression of CD45 isoforms and some adhesion molecules on T cells change during T cell activation. In CD4+ T cells, it has been reported that CD45RA is lost and CD45RO is up-regulated when CD4+ T cells are stimulated. This change seemed to be irreversible and thus CD45RA may serve as a marker for virgin T cells and CD45R0 as a marker for memory T cells in CD4+ T cells. In CD8+ T cells, however, the expression of CD45 isoform has been less well understood. We have previously reported the switching of CD45 isoform expression may be reversible and CD8+CD45RA+ T cells may contain preactivated T cells. We present further evidence to support this notion by investigating the expression of lymphocyte function-associated Ag (LFA-1) in relation to CD45 isoform expression in various T cell populations in the human. In the thymus and umbilical cord blood, more than 97% of both CD4+ and CD8+ single positive T cells expressed LFA-1 at a low level. In CD4+ peripheral blood T cells, a high level of LFA-1 expression was found only in the CD45RA- population: 98% of CD45RA+ cells were LFA-1low. In CD8+ peripheral blood T cells, in contrast, a distinct population of LFA-1high cells was found in CD45RA+ subset, comprising about 45% of this subset in a 32-yr-old donor. In 7 days after stimulation with PHA, all CD4+ and CD8+ T cells, irrespective of their CD45 isoform expression, were LFA-1high. The proportion of CD45RA+ cells decreased in CD4+ but slightly increased in CD8+ T cells after the stimulation. These results support the notion that CD45RA and CD45R0 mark virgin and memory T cells respectively in the CD4+ T cells, and that CD8+CD45RA- T cells are primed. However, the validity of CD45RA as a marker of virgin cells in CD8+ T cells is seriously questioned.

摘要

T细胞活化过程中，T细胞上CD45异构体及一些黏附分子的表达会发生变化。在CD4⁺T细胞中，有报道称当CD4⁺T细胞受到刺激时，CD45RA会丢失，CD45RO会上调。这种变化似乎是不可逆的，因此在CD4⁺T细胞中，CD45RA可作为初始T细胞的标志物，CD45R0可作为记忆T细胞的标志物。然而，在CD8⁺T细胞中，CD45异构体的表达情况尚不太清楚。我们之前报道过CD45异构体表达的转换可能是可逆的，CD8⁺CD45RA⁺T细胞可能包含预激活的T细胞。我们通过研究人不同T细胞群体中与CD45异构体表达相关的淋巴细胞功能相关抗原（LFA-1）的表达，进一步提供证据支持这一观点。在胸腺和脐带血中，超过97%的CD4⁺和CD8⁺单阳性T细胞低水平表达LFA-1。在CD4⁺外周血T细胞中，仅在CD45RA⁻群体中发现高水平的LFA-1表达：98%的CD45RA⁺细胞LFA-1低表达。相比之下，在CD8⁺外周血T细胞中，在CD45RA⁺亚群中发现了一个明显的LFA-1高表达细胞群体，在一名32岁供体中约占该亚群的45%。用PHA刺激7天后，所有CD4⁺和CD8⁺T细胞，无论其CD45异构体表达如何，均为LFA-1高表达。刺激后，CD4⁺T细胞中CD45RA⁺细胞的比例下降，而CD8⁺T细胞中则略有增加。这些结果支持以下观点：在CD4⁺T细胞中，CD45RA和CD45R0分别标记初始T细胞和记忆T细胞，并且CD8⁺CD45RA⁻T细胞已被启动。然而，CD45RA作为CD8⁺T细胞中初始细胞标志物的有效性受到严重质疑。