Kvbeta2 and the host response to cyclic dinucleotides

项目总结 C-di-GMP、c-di-AMP和3‘3’-cGAMP等是调节品种的细菌第二信使 诱导宿主免疫的细菌生理和病原体相关分子模式(PAMP)方面 在感染过程中的反应。这些CDN广泛由细菌产生，更重要的是，对 人类病原体包括B组链球菌、结核分枝杆菌、 金黄色葡萄球菌、沙眼衣原体和单核细胞增多性李斯特菌。CDN还具有重要的 由于它们能够增强I型干扰素和适应性，因此有可能作为传染病的疫苗佐剂 免疫反应。识别PAMP的模式识别受体(PRR)是 细菌感染。因此，CDN PRR的鉴定和特征对于研究CDN PRR至关重要 传染病的发病机制及CDN作为疫苗佐剂的应用。在这里，我们识别了Kvb2， 电压依赖性钾通道KV1的胞浆b亚基，作为c-diAMP-相互作用蛋白通过 C-二-AMP亲和下拉试验。Kvb2是一种功能性的醛酮还原酶(AKR)，它调节细胞内 兴奋性取决于其NADPH辅因子的氧化和氧化还原状态。KVβ2广泛表达于 人类的大脑、心脏和淋巴器官。然而，Kvb2功能障碍的主要后果是 导致记忆障碍和癫痫发作的神经损伤。我们假设Kvb2是与生俱来的 神经免疫系统中通过检测CDN和潜在的CDN来感知细菌感染的免疫保护 氧化应激。我们的目标是(I)表征Kvb2与CDN结合的特异性和动力学，以及 Kvb2对CDN结合调节Kv通道的机制：(Ii)研究Kvb2在 利用小胶质细胞系和L. 单核细胞增多性脑膜炎小鼠模型。我们的研究将把细胞的兴奋性与检测 细菌感染，这将拓宽我们对CDN介导的中枢抗菌免疫的理解 神经系统。

PROJECT SUMMARY C-di-GMP, c-di-AMP, and 3′3′-cGAMP, among others, are bacterial second messengers that regulate a variety aspects of bacterial physiology and pathogen-associated molecular patterns (PAMPs) that elicit host immune responses during infection. These CDNs are widely produced by bacteria, and more importantly, crucial for the pathogenesis of human pathogens including Group B Streptococcus, Mycobacterium tuberculosis, Staphylococcus aureus, Chlamydia trachomatis and Listeria monocytogenes. CDNs also have significant potential as vaccine adjuvants for infectious diseases due to their capability to boost type I IFN and adaptive immune responses. Pattern recognition receptors (PRRs) that recognize PAMPs are the first line defense for bacterial infection. Identification and characterization of CDN PRRs are therefore critical to the study of pathogenesis of infectious diseases and the application of CDNs as vaccine adjuvants. Here, we identified Kvb2, the cytosolic b subunit of voltage-dependent potassium channel Kv1, as a c-di-AMP-interacting protein through c-di-AMP affinity pull-down assay. Kvb2 is a functional aldo-keto reductase (AKR) which modulates the cellular excitability depending on the oxidative and redox status of its NADPH cofactor. Kvβ2 is widely expressed in human brain, heart and lymphoid organs. However, the dominating consequence of Kvb2 dysfunction is causing neurological impairments that leads to memory impairments and seizures. We hypothesize that Kvb2 is an innate immune guard in the neuroimmune system that senses bacterial infection by detecting CDNs and potential oxidative stresses. We aim to (i) characterize the specificity and dynamics of Kvb2 for CDN binding, as well as the mechanisms of Kv channel modulation by Kvb2 response to CDN binding; (ii) investigate the role of Kvb2 in restricting bacterial growth and modulating innate immune responses using a microglia cell line and L. monocytogenes meningitis mouse model. Our studies will couple the excitability of cells with detection of bacterial infection, which will broaden our understanding of CDN-mediated antibacterial immunity in the central nervous system.