Boursalian T E, Bottomly K
Section of Immunobiology, Yale University School of Medicine, Howard Hughes Medical Institute, New Haven, CT 06511, USA.
J Immunol. 1999 Jan 1;162(1):9-16.
The reliable identification of naive and memory CD4 T cells is critical to understanding the cellular basis of immunological memory. However, it has long been a controversial issue whether naive and memory phenotypes are stable among resting CD4 T cells in the absence of overt stimulation or whether the proposed memory phenotype is a transient, reversible one that represents recently activated cells. In this study, adoptively transferred, purified populations of naive or memory phenotype CD4 T cells are monitored over time to assess the stability of phenotypes and the functional capabilities of transferred cells. Studying both TCR transgenic and nontransgenic CD4 T cell populations allows one to control for the capacity to respond to environmental Ags in vivo. Several findings are reported. The first is that in the absence of Ag, both naive and memory phenotypes remain unchanged over time. Second, when changes are seen in populations of transferred naive phenotype CD4 T cells, they take place only when there is a potential for antigenic challenge, suggesting that it is an Ag-driven event. Furthermore, when a change from naive to memory phenotype is observed, these transferred donor cells also function as memory cells. Third, the ability of memory CD4 T cells to retain the memory phenotype is independent of specific Ag.
准确识别初始和记忆性CD4 T细胞对于理解免疫记忆的细胞基础至关重要。然而，在没有明显刺激的情况下，初始和记忆表型在静息CD4 T细胞中是否稳定，或者所提出的记忆表型是否是一种代表最近活化细胞的短暂、可逆表型，长期以来一直是一个有争议的问题。在本研究中，对过继转移的纯化初始或记忆表型CD4 T细胞群体进行长期监测，以评估表型的稳定性和转移细胞的功能能力。研究TCR转基因和非转基因CD4 T细胞群体能够控制体内对环境抗原的反应能力。报告了几个发现。第一个发现是，在没有抗原的情况下，初始和记忆表型随时间保持不变。其次，当在过继转移的初始表型CD4 T细胞群体中观察到变化时，只有在存在抗原挑战的可能性时才会发生，这表明这是一个由抗原驱动的事件。此外，当观察到从初始表型向记忆表型转变时，这些过继转移的供体细胞也发挥记忆细胞的功能。第三，记忆性CD4 T细胞保留记忆表型的能力与特定抗原无关。
