Molecular Role of Bruton’s Tyrosine Kinase (BTK) in NLRP3 Inflammasome Activation

NLRP 3炎性体已经出现在感染、组织损伤或细胞应激期间的外源性和内源性（无菌）损伤后形成的关键多蛋白复合物，并且其组装被认为是引发炎症的关键过程。例如，人类的多种疾病，从葡萄球菌感染到糖尿病到缺血性中风或心脏病发作，都与NLRP 3炎性小体有关。阐明（i）其作用的分子机制，（ii）调节分子;和（iii）药理学抑制剂是当前免疫学和炎症研究的关键挑战。我们已经鉴定出众所周知的信号分子布鲁顿的酪氨酸激酶（BTK）在小鼠和人类的NLRP 3炎性体活化中出乎意料地起关键作用。希望靶向NLRP 3炎性体的策略可能需要数年才能达到临床意义;然而，BTK作为NLRP 3调节剂的发现提供了独特的机会，通过有效且耐受性良好的FDA批准的抑制剂，例如伊曲替尼（PCI-32765），以众所周知的药理学靶标BTK的水平靶向NLRP 3炎性体。为了安全地这样做，需要首先解决进一步的重要开放问题：1）BTK在炎性小体激活中的机制分子和细胞作用是什么？具体而言，BTK的酪氨酸激酶活性和与NLRP 3修饰、激活和组装中涉及的其他蛋白结构域相关的潜在额外功能如何？2)在涉及NLRP 3炎性小体的无菌和非无菌炎症状态中，BTK参与炎性小体活化的体内意义和治疗潜力是什么？我们在这里描述了我们如何在鼠和人原代细胞中采用体外分析，新型和细胞特异性鼠体内模型和患者离体分析，以全面解决这些问题，详见工作计划。我们的愿景是阐明BTK-NLRP 3炎性体的分子工作机制，使其能够安全地利用BTK作为靶向NLRP 3调节剂的巨大翻译潜力。

The NLRP3 inflammasome has emerged a critical multi-protein complex formed upon exogenous and endogenous (sterile) insults during infection, tissue damage or cellular stress and its assembly has been considered a key process in initiating inflammation. For example, multiple diseases in humans, ranging from Staphylococcal infections to diabetes to ischemic stroke or heart attack, have been linked to the NLRP3 inflammasome. The elucidation of (i) its molecular mechanism of action, (ii) regulatory molecules; and (iii) pharmacological inhibitors are key challenges in immunology and inflammation research at current. We have identified the well-known signaling molecule Bruton’s Tyrosine Kinase (BTK) to unexpectedly play a critical role in NLRP3 inflammasome activation in both mice and humans. Strategies hoping to target the NLRP3 inflammasome are probably years from reaching clinical significance; however, the discovery of BTK as an NLRP3 regulator offers the unique opportunity to target the NLRP3 inflammasome at the level of a well-known pharmacological target, BTK, via efficacious and well-tolerated FDA-approved inhibitors, e.g. ibrutinib (PCI-32765). To safely do so, further vital open questions need to be addressed first: 1) What is the mechanistic molecular and cellular role of BTK in inflammasome activation? Specifically, how are the tyrosine kinase activity of BTK and potential additional functions related to its other protein domains involved in NLRP3 modification, activation and assembly? 2) What is the in vivo significance and therapeutic potential of BTK’s involvement in inflammasome activation in sterile and non-sterile inflammatory states involving the NLRP3 inflammasome? We describe here how we would like to employ in vitro analyses in murine and human primary cells, novel and cell-specific murine in vivo models and patient ex vivo analyses to comprehensively address these questions as detailed in the work program. Our vision is to elucidate the molecular workings of the BTK-NLRP3 inflammasome to a level that will allow for safely harnessing the considerable translational potential of BTK as a targetable NLRP3 regulator.