DEFINING THE FUNCTION OF EXTRACELLULAR ATP SENSING FOR MEMORY CD8+ T CELL GENERATION AND LONGEVITY

项目总结 细胞外三磷酸腺苷(ATP)是一种进化保守的“危险信号”，用于感知细胞 损坏。在小鼠和人类中，细胞外ATP(EATP)是由嘌呤能受体识别的。其中包括 受体，P2RX7特别相关，因为它优先在免疫细胞中表达，能够 激活先天免疫反应和获得性免疫反应。功能性适应性免疫反应--尤其是T细胞 记忆--对控制病毒感染至关重要。值得注意的是， 我们最近出版的作品 显示出P2RX7 对于病毒特异性长寿命记忆CD8+T细胞的产生和维持至关重要。P2RX7似乎 控制CD8+T细胞的代谢适合性，特别是线粒体功能和活性。 免疫反应。尽管这些发现表明在不同的时间点需要P2RX7 效应器免疫反应，尚不清楚在免疫反应过程中何时需要P2RX7/eATP信号 为充分发育记忆性CD8+T细胞。另一个未探索的问题是eATP的来源 P2RX7在CD8+T细胞的整个免疫反应中被激活。EATP可以起源于周围环境 微环境(CD8+T细胞-外源性)，很可能在初级或次级抗原期间发生 也可以由自身的CD8+T细胞通过PAnnexin 1(Panx1)通道(即CD8+T细胞- 在长期记忆中，当炎症消退时，这一点尤其相关。在目标1中，我们 将使用P2RX7和Panx1消融工具来阐明在整个手术过程中是否需要P2RX7/eATP传感 效应器阶段或仅在早期激活期间-以及该阶段eATP的来源。目前也不清楚 记忆性CD8+T细胞的长期存活是否需要持续的P2RX7/eATP信号。在AIM 2 我们将在内存建立后使用工具敲除P2RX7和Panx1，以回答此问题并 阐明eATP来源可能与长期生存维持有关。最后，在目标3中，我们将 评估记忆CD8+T细胞在二次抗原遭遇时的回忆反应(以及 随后的保护性免疫反应)需要P2RX7介导的eATP信号。这些研究将会有所帮助 阐明eATP感应在记忆性CD8+T细胞动态平衡中的作用，并将对如何 “危险信号”和对细胞损伤的感知不仅有助于建立短期免疫，也有助于建立长期免疫。 对抗病原体。这将为今后疫苗和抗病毒免疫疗法的改进提供依据。 设计。

Project summary Extracellular adenosine triphosphate (ATP) is an evolutionary conserved “danger signal” used to sense cellular damage. In mice and humans, extracellular ATP (eATP) is recognized by purinergic receptors. Among those receptors, P2RX7 is particularly relevant since it is preferentially expressed in immune cells, being able to activate both innate and adaptive immune responses. Functional adaptive immune responses – especially T cell memory – are crucial for the control of viral infections. Notably, our recently published work shows that P2RX7 is crucial for the generation and maintenance of virus-specific long-lived memory CD8+ T cells. P2RX7 seems to control the metabolic fitness – in particular, mitochondrial function and viability – of CD8+ T cells throughout the immune response. Although these findings indicate that P2RX7 is required at different time points during an effector immune response, it is not clear when during an immune response P2RX7/eATP signaling is required for the full development of memory CD8+ T cells. Another unexplored question lies on the source of eATP for P2RX7 activation in CD8+ T cells throughout the immune response. eATP can originate from the surrounding microenvironment (being CD8+ T cell-extrinsic), which is likely to happen during primary or secondary antigen responses, or can be released by the own CD8+ T cell via Pannexin 1 (Panx1) channels (being CD8+ T cell- intrinsic) – this can be particularly relevant during long-term memory, when inflammation recedes. In Aim 1, we will use P2RX7 and Panx1 ablation tools to elucidate whether P2RX7/eATP sensing is required throughout the effector phase or only during early activation – as well as the source of eATP for this stage. It is also unclear whether sustained P2RX7/eATP signaling is required for long-term survival of memory CD8+ T cells. In Aim 2 we will use tools to knockout P2RX7 and Panx1 after memory establishment to answer this question and to elucidate the eATP source potentially involved in long-term survival maintenance. Finally, in Aim 3, we will evaluate if the recall responses of memory CD8+ T cells in response to a secondary antigen encounter (and the subsequent protective immune response) requires P2RX7-mediated eATP signaling. These studies will help elucidate the role of eATP sensing for memory CD8+ T cell homeostasis and will provide key insights on how “danger signals” and the sensing of cellular damage help build not only short-term but also long-term immunity against pathogens. This will provide the basis for the improvement of future vaccine and antiviral immunotherapy designs.