Perforin 2 controls unconventional cytokine release from mucosal APC

穿孔素2抑制粘膜APC非常规细胞因子的释放 项目摘要 专业抗原提呈细胞(APC)群体如何向T细胞集中递送细胞因子以塑造 粘膜组织的促炎和抗炎状态仍不完全清楚。特别是， 缺乏N端肽序列的细胞因子，如IL-1家族细胞因子IL-33，不能获得常规的 蛋白质分泌途径，这导致了流行的观点，即细胞死亡是IL-33释放的原因。 这个项目建立在一组令人兴奋的初步数据上，表明粘膜常规树突状细胞 在人类和小鼠的细胞(CDC)亚群中，都表达跨膜孔形成蛋白穿孔素-2，该蛋白 至少在小鼠身上，促进了IL-33的分泌。而在人类CDC中，我们发现穿孔素-2主要在 干扰素调节因子4(IRF4)亚群指示cDC2谱系，在小鼠CDC中，我们发现穿孔素-2在 CD103+cDC1亚群表达转录因子IRF8和BATF3。不管这种血统 经鉴定，人和小鼠呼吸道粘膜中的CD11c+细胞均含有胞浆IL-33蛋白。 我们的数据表明，抑制穿孔素-2活性可以阻止CDC释放IL-33，并抑制CDC 鲜为人知的ST2+GATA3+Foxp3+Treg亚群的增殖性扩张。鉴于穿孔素-2已经被 显示还通过控制IFNAR反应性来调节1型干扰素信号，我们提出了一个重要的 在人类和小鼠中存在依赖于黏膜APC表达穿孔素-2的调节机制。 该项目验证了APC需要穿孔素-2作为可诱导质膜的中心假设 非常规细胞因子在粘膜界面输送的管道。三个具体目标(SA)将是 调查过了。SA1将决定穿孔素-2+APC是否可预测鼻腔粘膜Treg亚群的丰度 并确定了穿孔素-2+APC的转录图谱。SA2将定义所需的穿孔素-2结构域 IL-33的释放、依赖穿孔素-2的分泌分子的多样性以及必要的细胞内转运 在APC-T细胞相互作用过程中负责穿孔素-2质膜定位的机制。SA3将 直接检测cDC1和/或cDC2亚群是否优先使用穿孔素-2驱动病原体特异性T细胞 呼吸道病毒或蠕虫感染小鼠模型的反应。总而言之，这个迷雾项目站得住脚 揭示一种新的范式，以了解疾控中心如何在呼吸道粘膜内指导免疫。

Perforin 2 controls unconventional cytokine release from mucosal APC Project Summary How professional antigen presenting cell (APC) populations focally deliver cytokines to T cells for shaping the pro-inflammatory vs. anti-inflammatory status of mucosal tissue remains incompletely understood. In particular, cytokines that lack N-terminal peptide sequence such as the IL-1 family cytokine IL-33 can't access conventional protein secretion pathways, which has led to the prevailing view that cell death is responsible for IL-33 release. This project is built upon an exciting set of preliminary data demonstrating that mucosal conventional dendritic cell (cDC) subsets, in both humans and mice, express the transmembrane pore-forming protein Perforin-2, which at least in mice, facilitates IL-33 secretion. While in human cDC, we find Perforin-2 expression primarily in an interferon regulatory factor 4 (IRF4) subset indicating the cDC2 lineage, in mouse cDC, we find Perforin-2 in the CD103+ cDC1 subset known to express the transcription factors Irf8 and Batf3. Irrespective of this lineage distinction, both human and mouse CD11c+ cells in the respiratory mucosa contain cytoplasmic IL-33 protein. Our data demonstrate that inhibition of Perforin-2 activity prevents IL-33 release from cDC and inhibits the proliferative expansion of a poorly understood ST2+GATA3+Foxp3+Treg subset. Given that Perforin-2 has been shown to also regulate Type 1 IFN signaling through controlling IFNAR responsiveness, we propose an important regulatory mechanism exists in humans and mice that is dependent upon mucosal APC that express Perforin-2. This project tests the central hypothesis that APC require Perforin-2 as an inducible plasma membrane conduit for unconventional cytokine delivery at the mucosal interface. Three specific aims (SA) will be investigated. SA1 will determine whether Perforin-2+ APC predict Treg subset abundance in sinonasal mucosa and define the transcriptional landscape of Perforin-2+ APC. SA2 will define the Perforin-2 domains required for IL-33 release, the diversity of Perforin-2-dependent secreted molecules, and the requisite intracellular trafficking machinery responsible for Perforin-2 plasma membrane localization during APC-T cell interactions. SA3 will directly test whether cDC1 and/or cDC2 subsets preferentially use Perforin-2 for driving pathogen-specific T cell responses in mouse models of respiratory virus or helminth infection. Taken together, this MIST project stands to uncover a new paradigm for understanding how cDC instruct immunity within the respiratory mucosa.