ENHANCEMENT OF ADENOVIRUS INDUCED ANTIMALARIA PROTECTION

本项目的主要目的是增强和延长表达环孢子子（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，并阐明这种保护的分子机制。我们早期的研究表明，用Ade （CS）皮下免疫小鼠可诱导大量CS特异性T细胞，显著抑制疟疾寄生虫的肝内细胞发育，并在大约40%的免疫小鼠中产生无菌免疫。这种保护主要是由CD8+ T细胞介导的，而不是由干扰素介导的。我们目前计划阐明某些细胞溶解性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（Specific Aim number 1）。我们还计划通过使用共表达荧光绿色蛋白（Specific Aim number 2）的Ade (CS)，确定吸收这种病毒、处理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CD8+ T细胞表位的单个或多个重复序列的腺病毒在诱导抗疟疾免疫方面是否与Ade （CS）一样有效或更有效（Specific Aim number 3）。为了提高表达CS蛋白的重组腺病毒的免疫原性，增加保护性免疫反应的持续时间，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（Specific Aim number 4）。细胞因子（如GM-CSF或其他）以及趋化因子的选择将基于其已知的对疟疾或其他微生物抗原的反应增强活性。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，事实证明这更迅速。

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.