Evolutionary lead optimization for immunotherapy of Marburg & Ebola viruses

描述（由申请方提供）：本提案旨在开发一种新型免疫制剂，用于预防和治疗丝状病毒科马尔堡和埃博拉病毒的危及生命的感染，这些病毒可能被用作生物武器，造成严重的公共威胁。该提议基于甘露糖结合凝集素（MBL）是一种广谱的先天免疫分子的事实。这种血清蛋白识别广泛的病原体，如细菌、寄生虫和病毒，包括丝状病毒。初步数据表明，重组人MBL（rHuMBL）识别埃博拉病毒和马尔堡病毒的包膜糖蛋白。该观察结果连同MBL在第一线宿主防御中的作用，使其成为在暴露于丝状病毒之前和/或之后用作免疫抑制剂的强有力候选物。该项目的一个关键目标是评估已用于第一阶段临床研究的临床级rHuMBL，以及包含另一种凝集素样蛋白L-纤维胶凝蛋白的一部分的MBL的第二代衍生物。初步研究表明，这些新的凝集素嵌合体结合甘露聚糖，甘露聚糖是装饰丝状病毒的相同碳水化合物。这项拨款提案将利用马萨诸塞州总医院发育免疫学实验室的基础设施、研究人员在先天免疫领域的广泛科学经验、开发治疗性rHuMBL的丹麦生物技术公司Natlmmune的产品开发专长，以及美国陆军传染病医学研究所的高度专业化资源，感染已经建立。我们将评估rHuMBL和凝集素嵌合体激活凝集素补体途径和使用丝状病毒糖蛋白假型化的HIV颗粒调节体外吞噬功能的功效。此外，我们将研究这些凝集素在MBL、补体成分3、纤维胶凝蛋白-A（鼠形式的L-纤维胶凝蛋白）或其组合缺陷的遗传修饰小鼠品系中的保护功效，以阐明每种先天免疫分子在用天然丝状病毒致命攻击的啮齿动物中的相对作用。该提案的最终目标是开发rHuMBL或其衍生物的制剂，其可以由暴露于丝状病毒的士兵或平民在预防和/或治疗上使用。

DESCRIPTION (provided by applicant): This proposal is aimed at developing a novel immunotherapeutic that will prevent and treat life-threatening infections with Marburg and Ebola viruses of the filovirus family that might be manipulated as bioweapons posing grave public threats. The proposal builds on the fact that the mannose-binding lectin (MBL) is a broad-spectrum molecule of innate immunity. This serum protein recognizes a wide range of pathogens, such as bacteria, parasites and viruses including filoviruses. Preliminary data indicate that recombinant human MBL (rHuMBL) recognizes the envelope glycoproteins of Ebola and Marburg viruses. This observation, together with the role of MBL in first line host defense, makes it a strong candidate as an immunotherapeutic agent for use before and/or after exposure to filoviruses. A key goal of this project is to evaluate clinical grade rHuMBL that has been used in Phase 1 clinical studies in the first instance, and second generation derivatives of MBL that incorporate a part of L-ficolin, another lectin-like protein. Preliminary studies demonstrated that these novel lectin chimeras bind mannan, the same carbohydrate that adorns filoviruses. This grant proposal will leverage the infrastructure of the Laboratory of Developmental Immunology at Massachusetts General Hospital, the extensive scientific experience of the investigators in the field of innate immunity, the product development expertise of Natlmmune, a Danish biotechnology company that developed therapeutic rHuMBL, and the highly specialized resources of the United States Army Medical Research Institute for Infectious Diseases where mouse and guinea pig models of filovirus infection have been established. We will evaluate the efficacy of rHuMBL and lectin chimeras to activate the lectin complement pathway and to modulate phagocytic function in vitro using HIV particles pseudotyped with filovirus glycoproteins. Furthermore, we will investigate the protective efficacy of these lectins in strains of genetically modified mice deficient in MBL, complement component 3, ficolin-A (murine form of L-ficolin) or combinations thereof to elucidate the relative roles of each innate immune molecule in rodents fatally challenged with native filoviruses. The ultimate goal of this proposal is to develop a formulation of rHuMBL or a derivative thereof that could be used prophylactically and/or therapeutically by soldiers or civilians exposed to filoviruses.