Lactoferrin as an Adjuvant for Cellular Immunity

描述（由申请人提供）： 本项目的总体目标是开发人重组乳铁蛋白作为卡介苗的佐剂，以增强细胞介导的免疫力（CMI），并在感染结核分枝杆菌后保护肺泡完整性。改进的无毒佐剂，特别是能够诱导CMI的佐剂，是免疫学研究和人用和兽用疫苗开发所需要的。这对于防治结核病的疫苗的开发尤其如此，其中M.牛卡介苗（BCG）作为疫苗未能成功地减少世界范围内的发病率。其他诱导CMI的佐剂毒性太大，不能用于人类，因此在动物中逐渐受到限制。乳铁蛋白不同于微生物佐剂和细胞因子佐剂;它是直接参与宿主防御和诱导细胞介导的免疫应答的天然效应分子。I期研究表明，乳铁蛋白作为佐剂与BCG一起给予，以剂量依赖性方式增强小鼠的迟发型超敏反应（DTH），且无明显毒性。从机制上讲，它诱导巨噬细胞产生IL-12和TNF-α，从而产生可能将免疫应答推向CMI发展和维持的局部环境。我们的I期数据表明乳铁蛋白增强BCG疫苗接种，如通过增加的淋巴细胞增殖以及针对BCG抗原的IFN-γ、IL-2和IL-12（p40）产生所证明的。此外，乳铁蛋白疫苗接种后用毒性结核分枝杆菌（MTB）进行的气溶胶激发证明了向脾脏的微生物传播减少，并显著改善了肺病理学，与完全弗氏佐剂对照相当。第II阶段将专门解决在巴斯德毕赤酵母中产生的重组乳铁蛋白的新型、完全人源化糖型作为佐剂以增强BCG疫苗接种对随后用毒性MTB攻击的功效的效用和功效。

DESCRIPTION (provided by applicant): The overall goal of this project is to develop human recombinant Lactoferrin as an adjuvant to BCG to augment cell mediated immunity (CMI) and protect alveolar integrity upon infection with Mycobacterium tuberculosis. Improved nontoxic adjuvants, especially adjuvants capable of inducing CMI, are needed for research in immunology and for development of human and veterinary vaccines. This is especially true for development of vaccines to combat tuberculosis, where efficacy of the bacille Calmette-Guerin strain of M. bovis (BCG) as a vaccine has been unsuccessful to curtail worldwide incidence. Other adjuvants that do induce CMI are much too toxic for use in humans and are being progressively restricted in animals. Lactoferrin is different from microbial adjuvants and from cytokine adjuvants; it is a natural effector molecule that directly participates in host defenses and in the induction of cell mediated immune responses. Phase I studies demonstrate that Lactoferrin as an adjuvant given with BCG enhances delayed type hypersensitivity (DTH) in mice in a dose dependent fashion with no apparent toxicity. Mechanistically, it induces IL-12 and TNF-alpha production by macrophages thereby generating a local environment likely to push immune responses towards development and maintenance of CMI. Our Phase I data indicates Lactoferrin augments BCG vaccination as demonstrated by increased lymphocytic proliferation, and IFN-gamma, IL-2 and IL-12(p40) production towards BCG antigens. Furthermore, aerosol challenge with virulent Mycobacterium tuberculosis (MTB) following Lactoferrin vaccination demonstrated reduction in organism dissemination to spleen, and markedly improved lung pathology that was comparable to Complete Freund's Adjuvant controls. Phase II will specifically address the utility and efficacy of a novel, fully humanized glycoform of recombinant Lactoferrin produced in Pichia pastoris as an adjuvant to augment efficacy of BCG vaccination to subsequent challenge with virulent MTB.