Targeting T3SA proteins as protective antigens against Yersinia

摘要 鼠疫耶尔森氏菌引起腺鼠疫、败血症鼠疫和肺鼠疫，死亡率高。 没有立即得到治疗。尽管鼠疫杆菌对许多抗生素敏感，而且暴发的 在今天，鼠疫在鼠疫流行的地区继续造成致命的人类感染 已经在野生啮齿动物中建立了持续的地方病循环。2015年，中国报告了15例鼠疫病例。 美国，有几起发生在国家公园，病死率约为33%。这突显了 与这一毁灭性疾病作斗争的相关挑战。此外，鼠疫杆菌已被部署为 一种生物武器，具有其遗传易操纵性，自然获得的抗生素耐药性和亲缘关系 鼠疫杆菌很容易从自然中获得，已被归类为一种可武器化的病原体，具有 造成了广泛的人类死亡。耶尔森氏菌(Yersinia spp.)对人类有致病作用的人拥有III型 对毒力至关重要的分泌系统(T3SS)。这种T3SS将蛋白质效应器注入宿主细胞以 为了细菌的利益而操纵功能。T3SS装置(T3SA)为 将这些效应物从细菌转移到宿主细胞细胞质的管道。外在的 T3SA的一部分是针、尖端蛋白和两个转位蛋白中的第一个。对于叶尔西尼亚来说， LcrV是针尖蛋白，YopB是第一转位蛋白。这些蛋白质是高度保守的 耶尔森氏菌(Yersinia Spp)是致病所必需的。我们已经证明，当给药时， 鼻腔注射(IN)在适当佐剂的存在下，这两种蛋白质可保护小鼠免受致死性 鼠疫耶尔森氏菌和小肠结肠炎耶尔森菌的挑战。我们已经融合了LCrV和YopB来产生YerF，并且已经融合了 产肠毒素大肠杆菌DmLT(双突变不稳定毒素)的活性部分LTA1至N-末端 这些融合产生了L-耶尔菲。在这项建议中，我们打算将L-耶尔菲作为一个自我 佐剂保护性亚单位疫苗。我们假设L-耶夫将提供体液和细胞 免疫反应，将保护小鼠免受引起肺炎和腺鼠疫的感染。

Summary Yersinia pestis causes bubonic, septicemic and pneumonic plague with high rates of mortality in the absence of immediate treatment. Although Y. pestis is susceptible to many antibiotics and outbreaks have been contained in present day, plague continues to cause lethal human infections in areas where Y. pestis has established persistent enzootic cycles in wild rodents. In 2015, 15 plague cases were reported in the United States, several occurring in National Parks, with a case fatality rate of ~33%. This underscores the challenges associated with combatting this devastating disease. Additionally, Y. pestis has been deployed as a biological weapon and with its genetic tractability, natural acquisition of antibiotic resistance and relative ease of acquisition from nature, Y. pestis has been classified as a weaponizable pathogen with the potential for inflicting widespread human death. Yersinia spp. that are pathogenic for humans possess a type III secretion system (T3SS) that is essential for virulence. This T3SS injects protein effectors into host cells to manipulate functions for the benefit of the bacterium. The T3SS apparatus (T3SA) provides the energized conduit for translocation of these effectors from the bacterium and into the host cell cytoplasm. The external portions of the T3SA are the needle, the tip protein and the first of two translocator proteins. For Yersinia, LcrV is the needle tip protein and YopB is the first translocator protein. These proteins are highly conserved among Yersinia spp. and are required for pathogenesis. We have demonstrated that, when administered intranasally (IN) in the presence of the appropriate adjuvant, these two proteins protect mice against a lethal challenge by Y. pestis and Y. enterocolitica. We have fused LcrV and YopB to produce YerF and have fused LTA1, the active moiety of dmLT (double mutant labile toxin) from enterotoxigenic E. coli, to the N-terminus of these fusions to produce L-YerF. Within this proposal, we intend to assess the L-YerF as a self- adjuvanting protective subunit vaccine. We hypothesize that L-YerF will provide humoral and cellular immune responses that will protect mice against infections causing pneumonic and bubonic plague.