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: 6966960
• 负责人: Sara Lustigman
• 金额: $ 23.7万
• 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/6966960
• 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）： 以最终的目的是针对可能用作生物武器的病原体开发安全有效的人类免疫增强剂，我们将通过从人类寄生虫OnChocerca volvulus中克隆的强烈免疫刺激蛋白在小鼠中引发的免疫机制。在我们的原则研究中，无LPS的重组O. volvulus活化相关蛋白-1（ROV-ASP-1）充当了疫苗接种的小鼠中抗体反应的有力佐剂：1）卵形蛋白； 2）来自SARS-COV的尖峰区域的肽； 3）HIV-1多肽。蛋白质增强抗原的抗体滴度超过了最佳剂量的明矾或核糖佐剂和小鼠良好耐受蛋白质的抗体。接受寄生虫蛋白接受卵蛋白的小鼠的细胞反应主要是Th1型。该蛋白质还刺激了高水平的促炎细胞因子（IFN-Gamma，TNF-Alpha和GM-CSF）和IL-10分泌，从天真的人类白细胞中分泌。 ROV-ASP-1与> 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。为了最大程度地提高辅助蛋白的可能治疗应用，现在重要的是要详细建立其针对明确定义的，共同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，定义由ROV-ASP-1蛋白辅助剂在用已知是保护性免疫靶标的人类病原体抗原免疫的小鼠中引发的体液和细胞反应的类型。具体而言，我们将使用重组SARS-COV受体结合结构域，当与Francisella toluaremenis的Freund辅助和重组TUL4抗原结合使用时，可以刺激小鼠中和小鼠的有效中和抗体，这是一种经过证实的免疫小鼠细胞介导的免疫的靶标。其次，根据我们对蛋白质的分子结构的了解（包括假定的趋化因子样结构域），对ROV-ASP-1的亚基进行结构 - 功能研究，目的是识别具有最佳辅助性的可能的活性位点。基于初步数据，我们假设ROV-ASP-1将能够刺激抗体和TH1/CD8+ T细胞反应与针对SARS-COV和F. tularensis的保护相关的TH1/CD8+ T细胞反应。此外，研究ROV-ASP-1的合理选择亚基的生物活性将有助于确定蛋白质的作用方式，并有助于具有最佳辅助性和/或定义能力引起特定效应途径的分子的设计。