Department of Hematopoiesis, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.
Department of Experimental Immunology, Amsterdam UMC, Amsterdam, Netherlands.
Sci Immunol. 2018 Dec 14;3(30). doi: 10.1126/sciimmunol.aau1022.
Tissue-resident memory T cells (T) are noncirculating immune cells that contribute to the first line of local defense against reinfections. Their location at hotspots of pathogen encounter frequently exposes T to tissue damage. This history of danger-signal exposure is an important aspect of T-mediated immunity that has been overlooked so far. RNA profiling revealed that T from liver and small intestine express P2RX7, a damage/danger-associated molecular pattern (DAMP) receptor that is triggered by extracellular nucleotides (ATP, NAD). We confirmed that P2RX7 protein was expressed in CD8 T but not in circulating T cells (T) across different infection models. Tissue damage induced during routine isolation of liver lymphocytes led to P2RX7 activation and resulted in selective cell death of T P2RX7 activation in vivo by exogenous NAD led to a specific depletion of T while retaining T The effect was absent in P2RX7-deficient mice and after P2RX7 blockade. TCR triggering down-regulated P2RX7 expression and made T resistant to NAD-induced cell death. Physiological triggering of P2RX7 by sterile tissue damage during acetaminophen-induced liver injury led to a loss of previously acquired pathogen-specific local T in wild-type but not in P2RX7 KO T cells. Our results highlight P2RX7-mediated signaling as a critical pathway for the regulation of T maintenance. Extracellular nucleotides released during infection and tissue damage could deplete T locally and free niches for new and infection-relevant specificities. This suggests that the recognition of tissue damage promotes persistence of antigen-specific over bystander T in the tissue niche.
组织驻留记忆 T 细胞(T)是循环免疫细胞,有助于针对再感染的第一道局部防御。它们位于病原体遭遇的热点部位,经常暴露于组织损伤中。这种危险信号暴露的历史是 T 介导免疫的一个重要方面,迄今为止一直被忽视。RNA 谱分析显示,来自肝脏和小肠的 T 表达 P2RX7,这是一种损伤/危险相关的分子模式(DAMP)受体,可被细胞外核苷酸(ATP、NAD)触发。我们证实,P2RX7 蛋白在 CD8 T 中表达,但在不同感染模型的循环 T 细胞(T)中不表达。在常规分离肝淋巴细胞过程中诱导的组织损伤导致 P2RX7 激活,并导致 T 选择性细胞死亡。体内外源性 NAD 诱导的 P2RX7 激活导致 T 的特异性耗竭,同时保留 T。在 P2RX7 缺陷小鼠和 P2RX7 阻断后,该效应不存在。TCR 触发下调 P2RX7 表达,使 T 对 NAD 诱导的细胞死亡具有抗性。在乙酰氨基酚诱导的肝损伤期间,无菌组织损伤对 P2RX7 的生理性触发导致先前获得的病原体特异性局部 T 在野生型中丢失,但在 P2RX7 KO T 细胞中不丢失。我们的结果强调了 P2RX7 介导的信号作为调节 T 维持的关键途径。感染和组织损伤期间释放的细胞外核苷酸可能会局部耗竭 T,并为新的和与感染相关的特异性提供游离的生态位。这表明组织损伤的识别促进了抗原特异性 T 在组织龛中的持久性。