Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA.
J Immunol. 2012 Dec 1;189(11):5206-11. doi: 10.4049/jimmunol.1200137. Epub 2012 Oct 22.
In response to pathogen insult, CD8 T cells undergo expansion and a dynamic differentiation process into functionally different subpopulations. In this study, we show that during the effector response to influenza virus infection lung CD8 T cell subsets expressing killer cell lectin-like receptor G1 (KLRG1)(high) or KLRG1(low) had similar effector functions and immediate recall efficacy. The KLRG1 expression profile of lung CD8 T cells was not permanent after adoptive transfer and recall. Airway CD8 T cells exhibited a unique phenotype expressing low levels of KLRG1 together with high levels of markers of cellular activation. We investigated the functional characteristics of these cells by analyzing their capacity to survive and to respond to a secondary challenge outside of the airway environment. KLRG1(high) CD8 T cells isolated from the lung during the peak of the effector T cell response could survive for more than a month in the absence of cognate viral Ags after systemic adoptive transfer, and these "rested" CD8 T cells proliferated and participated in a recall response to influenza virus infection. These data highlight the unique phenotype and plasticity of effector CD8 T cell responses in the lung.
针对病原体的侵袭，CD8 T 细胞经历扩增和动态分化过程，形成具有不同功能的亚群。在这项研究中，我们发现，在流感病毒感染的效应应答过程中，肺脏 CD8 T 细胞亚群中表达杀伤细胞凝集素样受体 G1（KLRG1）（高）或 KLRG1（低）的子集具有相似的效应功能和即时记忆效果。肺脏 CD8 T 细胞的 KLRG1 表达谱在过继转移和回忆后并不是永久性的。气道 CD8 T 细胞表现出独特的表型，表达低水平的 KLRG1，同时高水平表达细胞激活标志物。我们通过分析这些细胞在气道环境之外对二次挑战的存活和反应能力来研究这些细胞的功能特征。在效应 T 细胞应答高峰期从肺部分离出的 KLRG1（高）CD8 T 细胞，在全身过继转移后，在没有同源病毒抗原的情况下，可存活超过 1 个月，这些“静息”CD8 T 细胞增殖并参与流感病毒感染的回忆应答。这些数据突出了肺部效应 CD8 T 细胞应答的独特表型和可塑性。
