Koulova L, Yang S Y, Dupont B
Laboratory of Human Immunogenetics, Sloan-Kettering Institute for Cancer Research, New York, NY 10021.
J Immunol. 1990 Oct 1;145(7):2035-43.
The majority of peripheral CD4+ T lymphocytes proliferate in vitro in response to anti-CD3 in presence of autologous APC. The present study describes a subpopulation of CD4+ T cells that cannot be activated and progress into cell cycle by stimulation with anti-CD3 plus APC or with mitogenic combinations of anti-CD2. The in vitro responses of these anti-CD3-unresponsive CD4+ T cells were investigated with a panel of mAb to CD2, CD3, and CD28, and found to be similar to those previously observed for mature thymocytes: only the combination of anti-CD2 plus anti-CD28 produced cell proliferation. Anti-CD3-unresponsive T cells were CD45RA+, but represented only 14 to 22% of the CD4+, CD45RA+ T cell population. Activation with anti-CD2 plus anti-CD28 mAb resulted in major changes in the cell surface phenotype and functional properties: a loss of CD45RA+ occurred and an increased expression of CD45RO, CD29, and CD58 (LFA3), as well as a gain in responsiveness to anti-CD3 and anti-CD2. This change in CD45 phenotype from CD45RA to CD45RO occurs in both the anti-CD3-responsive and in the anti-CD3-unresponsive subsets of the CD45RA+, CD4+ cells after cell proliferation. The anti-CD3-unresponsive subset may represent a pool of not yet fully differentiated peripheral T cells. The acquisition of anti-CD3 responsiveness could occur as a consequence of Ag priming or by an Ag-independent mechanism. Involvement of the CD28 Ag in this process is suggested from the present study.
大多数外周血CD4+ T淋巴细胞在自体抗原呈递细胞（APC）存在的情况下，体外可因抗CD3刺激而增殖。本研究描述了一个CD4+ T细胞亚群，该亚群不能被抗CD3加APC刺激或抗CD2的促有丝分裂组合激活并进入细胞周期。用一组针对CD2、CD3和CD28的单克隆抗体研究了这些抗CD3无反应性CD4+ T细胞的体外反应，发现其与先前观察到的成熟胸腺细胞相似：只有抗CD2加抗CD28的组合能产生细胞增殖。抗CD3无反应性T细胞为CD45RA+，但仅占CD4+、CD45RA+ T细胞群体的14%至22%。用抗CD2加抗CD28单克隆抗体激活导致细胞表面表型和功能特性发生重大变化：CD45RA+丧失，CD45RO、CD29和CD58（淋巴细胞功能相关抗原3，LFA3）表达增加，以及对抗CD3和抗CD2的反应性增强。细胞增殖后，CD45RA+、CD4+细胞的抗CD3反应性和抗CD3无反应性子集均发生从CD45RA到CD45RO的CD45表型变化。抗CD3无反应性子集可能代表一组尚未完全分化的外周T细胞。抗CD3反应性的获得可能是抗原致敏的结果，也可能是通过非抗原依赖机制。本研究提示CD28抗原参与了这一过程。
