A Helminth-Derived Immune Potentiator for Biodefense

用于生物防御的蠕虫衍生免疫增强剂

• 批准号: 7140427
• 负责人: Sara Lustigman
• 金额: $ 19.75万
• 依托单位: NEW YORK BLOOD CENTER
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7140427
• 关键词: Escherichia coli; Filarioidae; Francisella tularensis; Freund' s adjuvant; SARS virus; active immunization; bacterial antigens; biotechnology; bioterrorism /chemical warfare; cellular immunity; clinical research; drug design /synthesis /production; drug screening /evaluation; expression cloning; helminthic antigen; humoral immunity; immune response; immunologic substance development /preparation; immunomodulators; laboratory mouse; molecular site; nonhuman therapy evaluation; ovalbumin; protein structure function; recombinant proteins; virus antigen; yeasts

DESCRIPTION (provided by applicant): With the ultimate goal of developing a safe and effective human immune potentiator against pathogens that may be used as bioweapons, we will characterize the immune mechanisms initiated in mice by a strongly immunostimulant protein cloned from the human parasite, Onchocerca volvulus. In our proof-of-principle studies, the LPS-free recombinant O. volvulus activation-associated protein-1 (rOv-ASP-1) acted as a powerful adjuvant for antibody responses in mice vaccinated with: 1) ovalbumin; 2) a peptide from the spike region of the SARS-CoV; 3) an HIV-1 polypeptide. Antibody titers to the antigens augmented by the protein exceeded those adjuvanted by optimal doses of alum or Ribi adjuvants and mice tolerated the protein well. Cellular responses in mice receiving ovalbumin with the parasite protein were predominantly Th1-type. The protein also stimulated high levels of pro-inflammatory cytokine (IFN-gamma, TNF-alpha and GM-CSF) and IL-10 secretion from naive human leukocytes in vitro. rOv-ASP-1 binds to > 94% of human of human B cells and monocytes, 29% of NK cells and 14.5% of CD8+ T cells. To maximize the possible therapeutic applications of the adjuvant protein, it is now important to first establish in detail the humoral and cellular responses it initiates against well-defined, coadministered pathogen antigens. To achieve this we propose two specific aims. Firstly, to define the types of humoral and cellular responses initiated by the rOv-ASP-1 protein adjuvant in mice immunized with human pathogen antigens known to be targets of protective immunity. Specifically, we will use recombinant SARS-CoV receptor binding domain which stimulates potent neutralizing antibodies in mice when combined with Freund's adjuvant and recombinant TUL4 antigen of Francisella tularensis, a proven target of cell-mediated immunity in immunized mice. Secondly, to perform structure-function studies on subunits of rOv- ASP-1, based on what we know about the molecular structure of the protein (including a putative chemokine-like domain), with the goal of identifying possible active sites with optimal adjuvanticity. Based on the preliminary data, we hypothesize that rOv-ASP-1 will be able to stimulate both antibody and Th1/CD8+ T cell responses relevant to protection against SARS-CoV and F. tularensis. Furthermore, studying the bioactivities of rationally-selected subunits of rOv-ASP-1 will help determine the mode of action of the protein and aid in the design of a molecule with optimal adjuvanticity and/or defined ability to elicit particular effector pathways.

描述（由申请人提供）： 我们的最终目标是开发一种安全有效的人类免疫增强剂来对抗可用作生物武器的病原体，我们将表征从人类寄生虫盘尾丝虫中克隆的强免疫刺激蛋白在小鼠中启动的免疫机制。在我们的原理验证研究中，不含 LPS 的重组盘旋丝虫激活相关蛋白 1 (rOv-ASP-1) 在接种以下疫苗的小鼠中充当抗体反应的强大佐剂： 1) 卵清蛋白； 2）来自SARS-CoV刺突区域的肽； 3)HIV-1多肽。经该蛋白质增强的抗原的抗体滴度超过了最佳剂量的明矾或Ribi佐剂所佐剂的抗体滴度，并且小鼠对该蛋白质具有良好的耐受性。接受卵清蛋白和寄生虫蛋白的小鼠的细胞反应主要是 Th1 型。该蛋白还在体外刺激初始人类白细胞分泌高水平的促炎细胞因子（IFN-γ、TNF-α和GM-CSF）和IL-10。 rOv-ASP-1 与超过 94% 的人类 B 细胞和单核细胞、29% 的 NK 细胞和 14.5% 的 CD8+ T 细胞结合。为了最大限度地发挥佐剂蛋白可能的治疗应用，现在重要的是首先详细确定它针对明确的、共同施用的病原体抗原引发的体液和细胞反应。为了实现这一目标，我们提出了两个具体目标。首先，确定在用已知为保护性免疫目标的人类病原体抗原免疫的小鼠中由 rOv-ASP-1 蛋白佐剂引发的体液和细胞反应的类型。具体来说，我们将使用重组 SARS-CoV 受体结合结构域，当与弗氏佐剂和土拉弗朗西斯菌的重组 TUL4 抗原结合使用时，该结构域会在小鼠体内刺激有效的中和抗体，土拉弗朗西斯菌是免疫小鼠中细胞介导免疫的已被证明的靶标。其次，根据我们对蛋白质分子结构（包括假定的趋化因子样结构域）的了解，对 rOv-ASP-1 亚基进行结构功能研究，目的是识别具有最佳佐剂性的可能活性位点。根据初步数据，我们假设 rOv-ASP-1 将能够刺激抗体和 Th1/CD8+ T 细胞反应，从而预防 SARS-CoV 和土拉热镰刀菌。此外，研究合理选择的 rOv-ASP-1 亚基的生物活性将有助于确定蛋白质的作用模式，并有助于设计具有最佳佐剂性和/或确定的引发特定效应途径能力的分子。