Barber Daniel L, Wherry E John, Ahmed Rafi
Emory Vaccine Center and Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322, USA.
J Immunol. 2003 Jul 1;171(1):27-31. doi: 10.4049/jimmunol.171.1.27.
In this study, we examined the cytotoxic activity of effector and memory CD8 T cells in vivo. At the peak of the CTL response following an acute lymphocytic choriomeningitis virus infection, effector CD8 T cells exhibited extremely rapid killing and started to eliminate adoptively transferred target cells within 15 min by a perforin-dependent mechanism. Although resting memory CD8 T cells are poorly cytolytic by in vitro (51)Cr release assays, there was rapid elimination (within 1-4 h) of target cells after transfer into immune mice, and both CD62L(high) and CD62L(low) memory CD8 T cells were able to kill rapidly in vivo. Strikingly, when directly compared on a per cell basis, memory CD8 T cells were only slightly slower than effector cells in eliminating target cells. These data indicate that virus specific memory CD8 T cells can rapidly acquire cytotoxic function upon re-exposure to Ag and are much more efficient killers in vivo than previously appreciated.
在本研究中，我们检测了效应性和记忆性CD8 T细胞在体内的细胞毒性活性。在急性淋巴细胞性脉络丛脑膜炎病毒感染后的CTL反应高峰期，效应性CD8 T细胞表现出极其快速的杀伤作用，并通过穿孔素依赖机制在15分钟内开始清除过继转移的靶细胞。尽管静息记忆性CD8 T细胞通过体外（51）Cr释放试验显示出较弱的细胞溶解能力，但在转移至免疫小鼠体内后，靶细胞能被快速清除（1 - 4小时内），并且CD62L（高表达）和CD62L（低表达）记忆性CD8 T细胞在体内均能快速杀伤。引人注目的是，当以单个细胞为基础直接比较时，记忆性CD8 T细胞在清除靶细胞方面仅比效应性细胞稍慢。这些数据表明，病毒特异性记忆性CD8 T细胞在再次接触抗原后可迅速获得细胞毒性功能，并且在体内是比之前所认识到的更高效的杀伤细胞。
