CD8⁺ T cell immunosurveillance dynamics influence the outcome of intracellular infections and cancer. Here we used two-photon intravital microscopy to visualize the responses of CD8⁺ resident memory T cells (T_RM cells) within the reproductive tracts of live female mice. We found that mucosal T_RM cells were highly motile, but paused and underwent in situ division after local antigen challenge. T_RM cell reactivation triggered the recruitment of recirculating memory T cells that underwent antigen-independent T_RM cell differentiation in situ. However, the proliferation of pre-existing T_RM cells dominated the local mucosal recall response and contributed most substantially to the boosted secondary T_RM cell population. We observed similar results in skin. Thus, T_RM cells can autonomously regulate the expansion of local immunosurveillance independently of central memory or proliferation in lymphoid tissue.

中文翻译：

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CD8+ 驻留记忆 T 细胞的活体粘膜成像显示出组织自主回忆反应，可增强次级记忆。


CD8 ⁺ T 细胞免疫监视动态影响细胞内感染和癌症的结果。在这里，我们使用双光子活体显微镜观察活体雌性小鼠生殖道内 CD8 ⁺常驻记忆 T 细胞（ _TRM细胞）的反应。我们发现粘膜_TRM细胞具有高度运动性，但在局部抗原攻击后暂停并进行原位分裂。 T _RM细胞重新激活触发了再循环记忆 T 细胞的募集，这些 T RM 细胞在原位进行了抗原非依赖性 T _RM细胞分化。然而，预先存在的 T _RM细胞的增殖主导了局部粘膜回忆反应，并对二次 T _RM细胞群的增强贡献最大。我们在皮肤中观察到类似的结果。因此， _TRM细胞可以自主调节局部免疫监视的扩展，独立于中枢记忆或淋巴组织的增殖。