ENHANCEMENT OF ADENOVIRUS INDUCED ANTIMALARIA PROTECTION

本研究的主要目的是增强和延长表达环子孢子（CS）蛋白的重组腺病毒[Ads（CS）]诱导的抗疟疾保护性免疫的持续时间，并阐明这种保护性免疫的分子机制。 我们早期的研究表明，Ade（CS）皮下免疫小鼠可诱导大量CS特异性T细胞，显著抑制疟原虫在肝细胞内的发育，并在约40%的免疫小鼠中产生无菌免疫。 这种保护作用主要由CD 8 + T细胞介导，但不受干扰素-γ介导。 我们目前计划阐明某些溶细胞性T细胞衍生分子在这种保护中的可能作用，如穿孔素、Fas-Fas配体等（具体目标编号1）。 我们还计划通过使用共表达荧光绿色蛋白（特异性目标编号2）的Ade（CS）来确定摄取该病毒、加工疟原虫抗原并将其呈递给T细胞的细胞的性质。我们将确定仅表达约氏疟原虫CS蛋白的相同CD 8 + T细胞表位的单个重复或多个重复的腺病毒在引发抗疟疾免疫性方面是否与Ade（CS）一样有效或比Ade（CS）更有效（具体目标编号3）。为了增加表达CS蛋白的重组腺病毒的免疫原性，并增加保护性免疫应答的持续时间，我们计划在病毒载体中与疟原虫蛋白共表达某些细胞因子或趋化因子（特定目的编号4）。 细胞因子如GM-CSF或其它以及趋化因子的选择将基于其已知的对疟疾或其它微生物抗原的应答的增强活性。 所有用于拟议研究的重组腺病毒都是在我的实验室里构建的，结果证明这更快。

The major goal of this project is to enhance and prolong the duration of the protective anti-malaria immunity elicited by a recombinant adenovirus expressing the circumsporozoite (CS) protein [Ads (CS)], and clarify the molecular mechanism of this protection. Our earlier studies had shown that the subcutaneous immunization of mice with Ade (CS) elicited a large number of CS specific T cells and a striking inhibition of the intrahepatocytic development of the malaria parasites, as well as sterile immunity in approximately 40 percent of the immunized mice. This protection was mediated primarily by CD8+ T cell, but was not mediated by interferon-gamma. We currently plan to clarify the possible role of certain cytolytic T cell derived molecules in this protection, such as perforin, Fas-Fas ligand, etc. (Specific Aim number 1). We also plan to determine the nature of the cells which take up this virus, process the plasmodial antigen and present it to T cells, by using Ade (CS) co-expressing the fluorescent green protein (Specific Aim number 2). We will determine whether adenovirus expressing only a single, or multiple repeats of the same CD8+ T cell epitopes of the CS protein of P. yoelii, are as effective or more than Ade (CS) in eliciting anti-malaria immunity (Specific Aim number 3). In order to increase the immunogenicity of the recombinant adenovirus expressing the CS protein, and increase the duration of the protective immune response, we plan to co-express certain cytokines or chemokines with the plasmodial protein in the viral vectors (Specific Aim number 4). The selection of a cytokine such as GM-CSF or others, as well as of a chemokine will be based on its known enhancing activity of the response to malaria or other microbial antigens. All the recombinant adenoviruses to be used in the proposed research are being constructed in my laboratory, which is turning out to be more expeditious.