The role of SERPINB1 in T cell function and its contribution to human diseases

项目总结 摘要原发性免疫缺陷是由先天性免疫缺陷引起的一组单基因疾病。 (IEI)会带来严重感染、自身免疫和癌症的风险。IEI的遗传学和免疫学研究 有助于了解人类免疫机制以及管理和治疗PIDs患者。他们的 研究对于了解与同一基因变异相关的更多常见疾病也是重要的 基因。然而，尽管从基础科学和临床研究PID的相关性和重要性 有观点认为，一半的PID患者缺乏基因诊断。通过研究一名患有不明原因的PID的患者 易患严重分枝杆菌病的遗传病因学，我们发现了一种无义突变 在serpinB1中。利用群体遗传学、生物化学和分子生物学的组合，我们表明 这是第一例被描述为serpinB1完全缺陷的病例。SerpinB1是一种胞内丝氨酸 蛋白水解酶自杀抑制剂。在小鼠体内缺乏它会导致细胞内蛋白酶活性失控，导致 中性粒细胞死亡和随后的中性粒细胞减少。有趣的是，我们的病人没有表现出任何中性粒细胞 异常，但相反，我们的深入免疫学特征显示， 活化的T细胞和CD4记忆T细胞。我们的发现表明，serpinB1具有一种以前未知的 T细胞功能与抗分枝杆菌免疫。我们的数据还表明，serpinB1编排了一个 细胞内蛋白水解酶介导的T细胞活化和存活所必需的途径。根据我们的发现，这一点 应用程序将检验serpinB1对人类T细胞激活至关重要的假设，并通过控制 细胞内蛋白水解酶活性，对人类疾病的影响。利用这位患者提供的独特机会 为了了解人类serpinB1的功能，我们提出了三种互补的方法。在目标1中，我们 将描述SerpinB1缺乏对T细胞激活和CD4T细胞的免疫学后果 差异化。我们还将研究丝氨酸B1缺失在T细胞中的转录后果。有了这个， 我们将揭示人类T细胞中一种以前未知的serpinB1功能。在目标2中，我们将确定和 描述由SerpinB1在T细胞中编排的通路。SerpinB1的缺失释放了 胞内蛋白酶的作用。这种罕见的pid机制将允许对这些蛋白酶的化学抑制。 用于治疗目的。此外，表征依赖于serpinB1的抗分枝杆菌机制 将导致在缺乏基因诊断的患者中在其途径中识别出额外的IEI。在目标3中，我们 将进行全表型关联研究(Phewas)，以确定遗传变异之间的关联 SerpinB1途径和其他人类疾病。这种反向遗传方法将扩大我们将 从一种罕见疾病的研究中学习，以造福更广泛的患者群体。我们提出的研究已经- 了解serpinB1介导的免疫、PID、抗-HBs的临床和生物学意义 分枝杆菌免疫，以及serpinB1途径对人类疾病的贡献。

PROJECT SUMMARY Primary immunodeficiencies (PIDs) are a group of monogenic diseases caused by inborn errors of immunity (IEI) that confer risk of severe infection, autoimmunity, and cancer. The genetic and immunological study of IEI is instrumental to understand mechanisms of human immunity and to manage and treat patients with PIDs. Their study is also important to understand more common diseases associated with genetic variants in the same genes. However, despite the relevance and importance of studying PIDs from the basic science and clinical points of view, half of the PID patients lack a genetic diagnosis. By studying a patient with a PID of unknown genetic etiology that confers susceptibility to severe mycobacterial disease, we identified a nonsense mutation in SERPINB1. Using a combination of population genetics, biochemistry, and molecular biology, we showed that this is the first case of SERPINB1 complete deficiency ever described. SERPINB1 is an intracellular serine protease suicide inhibitor. Its absence in mice causes uncontrolled intracellular protease activity, leading to neutrophil death and subsequent neutropenia. Interestingly, our patient does not display any neutrophil abnormality, but instead, our in-depth immunological characterization showed a reduction in the frequency of activated T cells and CD4+ memory T cells. Our findings suggest that SERPINB1 has a previously unknown function in T cells and antimycobacterial immunity. Our data also indicates that SERPINB1 orchestrates an intracellular protease-mediated pathway essential for T cell activation and survival. Given our findings, this application will test the hypothesis that SERPINB1 is critical for human T cell activation and, by controlling intracellular protease activity, to human diseases. Capitalizing on the unique opportunity that this patient offers to understand the function of human SERPINB1, we propose three complementary approaches. In Aim 1, we will characterize the immunological consequences of SERPINB1 deficiency on T cell activation and CD4+ T cell differentiation. We will also study the transcriptional consequences of SERPINB1 deficiency in T cells. With this, we will uncover a previously unknown function of SERPINB1 in human T cells. In Aim 2, we will identify and characterize the pathways orchestrated by SERPINB1 in T cells. The absence of SERPINB1 unleashes the action of intracellular proteases. This rare mechanism of PID will allow for chemical inhibition of these proteases for therapeutic purposes. Furthermore, characterizing the SERPINB1-dependent antimycobacterial mechanisms will lead to the identification of additional IEI in its pathway in patients lacking a genetic diagnosis. In Aim 3, we will perform phenome-wide association studies (pheWAS) to identify associations between genetic variants in the SERPINB1 pathway and additional human diseases. This reverse genetic approach will expand what we will learn from the study of a rare disease to benefit a broader group of patients. Our proposed research has far- reaching clinical and biological implications for understanding SERPINB1 mediated immunity, PIDs, anti- mycobacterial immunity, and the contribution of the SERPINB1 pathway to human disease.