LcrV Plague Vaccine with Altered Immune Modulatory Properties

性状（由申请方提供）：鼠疫耶尔森菌是鼠疫的病原体，在感染过程中分泌LcrV（低钙反应V或V抗原）。LcrV触发宿主免疫细胞释放白细胞介素10（IL-10）并抑制促炎细胞因子如肿瘤坏死因子α（TNF-α）和干扰素-γ（IFN-α）以及对抗鼠疫发病机制所需的先天防御机制。此外，LcrV在Yop毒力因子作为对抗先天性免疫应答的细菌手段向宿主细胞中的III型分泌机器依赖性递送中起重要作用。虽然用LcrV免疫动物可增强保护性免疫，但相关的宿主防御机制抑制可能妨碍全长LcrV作为人鼠疫疫苗的使用。在此，我们表明，LcrV内的短缺失可以降低其免疫调节特性。缺失氨基酸残基271-300的LcrV变体（rV 10）引发免疫应答，其保护小鼠免受完全毒性Y的致死性攻击。鼠疫CO 92菌株。当与全长LcrV相比时，rV 10免疫在肺鼠疫的鼠模型中提供更高水平的疫苗保护。与全长LcrV相比，rVlO显示出从小鼠和人巨噬细胞释放IL-10的能力降低。此外，LPS刺激的人或小鼠巨噬细胞释放促炎细胞因子被全长LcrV抑制，但不被rV 10变体抑制。因此，由于rV 10变体显示出显著降低的免疫调节特性和上级免疫原性，因此rV 10可能用作安全的人疫苗以产生针对鼠疫的保护性免疫。这一假设将由芝加哥大学、五大湖生物防御和新发传染病研究中心、Cambrex公司的一个跨学科科学家小组进行研究。SRI国际产品开发研究的结构是为了实现四个连续的里程碑。在开发rV 10的GLP大规模生产（里程碑1）和GMP级疫苗制备（里程碑2）后，将确定rV 10疫苗的免疫应答和安全性（里程碑3）。使用免疫动物的鼠疫攻毒，将遵循FDA-CBER动物规则条例检查疫苗有效性（里程碑4）。研究方案将与FDA-CBER密切合作设计，获得的全部信息将用于开发rV 10疫苗作为研究性新药，允许其未来用于人体临床试验。

DESCRIPTION (provided by the applicant): Yersinia pestis, the causative agent of plague, secretes LcrV (low calcium response V or V antigen) during infection. LcrV triggers release of interleukin 10 (IL-10) by host immune cells and suppresses pro- inflammatory cytokines such as tumor necrosis factor alpha (TNF-a) and interferon-gamma (IFN-Q) as well as innate defense mechanisms required to combat the pathogenesis of plague. Further, LcrV plays an important role in the type III secretion machinery-dependent delivery of Yop virulence factors into host cells as a bacterial means to combat innate immune responses. Although immunization of animals with LcrV elicits protective immunity, the associated suppression of host defense mechanisms may preclude the use of full length LcrV as a human plague vaccine. Herein we show that short deletions within LcrV can reduce its immune modulatory properties. An LcrV variant lacking amino acid residues 271-300 (rV10) elicited immune responses that protected mice against a lethal challenge with fully virulent Y. pestis strain CO92. When compared to full-length LcrV, rV10 immunization afforded greater levels of vaccine protection in a murine model of pneumonic plague. In contrast to full length LcrV, rV10 displayed reduced ability to release IL-10 from mouse and human macrophages. Further, LPS-stimulated release of pro-inflammatory cytokines by human or mouse macrophages was inhibited by full length LcrV but not by the rV10 variant. Thus, because the rV10 variant displays significantly reduced immune-modulatory properties and superior immunogenicity, rV10 can likely be used as a safe human vaccine to generate protective immunity against plague. This hypothesis will be pursued by an inter-disciplinary team of scientists at the University of Chicago, the Great Lakes RCE for Biodefense & Emerging Infectious Diseases, Cambrex Inc. and SRI International. Product development research is structured to achieve four successive milestones. Following development of GLP large scale production of rV10 (Milestone 1) and GMP grade vaccine preparation (Milestone 2), rV10 vaccine immune responses and safety will be determined (Milestone 3). Using plague challenge of immunized animals, FDA-CBER Animal Rule regulations will be followed to examine vaccine efficacy (Milestone 4). Research protocols will be designed in close collaboration with FDA-CBER and the entire body of acquired information will be used to develop rV10 vaccine as an Investigative New Drug, permitting its future use in human clinical trials.