A primary immune response is initiated in secondary lymphoid organs. Virtual memory CD8⁺ T (T_VM) cells are antigen-inexperienced T cells of a central memory phenotype, acquired through self-antigen–driven homeostatic proliferation. Unexpectedly, we find that T_VM cells are composed of CCR2⁺ and CCR2⁻ subsets that differentially elaborate a spectrum of effector- and memory-poised functions directly in the tissue. During a primary influenza infection, T_VM cells rapidly infiltrate the lungs in the first day after infection and promote early viral control. T_VM cells that recognize viral antigen are retained in the tissue, clonally expand independent of secondary lymphoid organs, and give rise to tissue-resident memory cells. By orchestrating an extralymphoid primary response, heterogenous T_VM cells bridge innate reaction and adaptive memory directly in the infected tissue.

初级免疫反应在次级淋巴器官中启动。虚拟记忆 CD8 ⁺ T (T _VM ) 细胞是具有中枢记忆表型的未经历抗原的 T 细胞，通过自身抗原驱动的稳态增殖获得。出乎意料的是，我们发现 T _VM细胞由 CCR2 ⁺和 CCR2 ^-亚群组成，它们直接在组织中以不同的方式详细阐述一系列效应器和记忆平衡功能。在原发性流感感染期间，T _VM细胞在感染后的第一天迅速浸润肺部并促进早期病毒控制。虚拟_机识别病毒抗原的细胞保留在组织中，独立于次级淋巴器官进行克隆扩增，并产生组织驻留记忆细胞。通过协调淋巴外初级反应，异源性 T _VM细胞直接在受感染组织中连接先天反应和适应性记忆。