Lactoferrin as an Adjuvant for Cellular Immunity

描述(申请人提供)：该项目的总体目标是开发重组人乳铁蛋白作为卡介苗的佐剂，以增强细胞免疫(CMI)，并在感染结核分枝杆菌时保护肺泡完整性。免疫学研究以及人类和兽医疫苗的开发需要改进的无毒佐剂，特别是能够诱导CMI的佐剂。对于抗击结核病的疫苗的开发尤其如此，卡介苗(BCG)作为疫苗的效力一直未能成功地减少全球发病率。其他确实会导致CMI的佐剂毒性太大，不能在人类身上使用，正在逐步限制在动物身上使用。乳铁蛋白不同于微生物佐剂和细胞因子佐剂，它是一种天然的效应分子，直接参与宿主防御和诱导细胞介导的免疫反应。I期研究表明，乳铁蛋白作为卡介苗的佐剂，以剂量依赖的方式增强小鼠的迟发性超敏反应(DTH)，没有明显的毒性。在机制上，它诱导巨噬细胞产生IL-12和TNF-α，从而产生一个局部环境，可能推动免疫反应向CMI的发展和维持发展。我们的第一阶段数据显示，乳铁蛋白增加了卡介苗的接种，表现为增加了淋巴细胞的增殖，以及针对卡介苗抗原产生的干扰素-γ、IL-2和IL-12(P40)。此外，在接种乳铁蛋白后，用强毒结核分枝杆菌(MTB)进行气雾剂攻击，显示出机体向脾扩散的减少，并显著改善了与完全弗氏佐剂对照组相当的肺部病理。第二阶段将专门讨论在毕赤酵母中生产的一种新型的、完全人源化的重组乳铁蛋白糖型作为佐剂的实用性和有效性，以增强卡介苗接种的效力，以应对随后的毒力结核杆菌的挑战。

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.