TRAP AS A CANDIDATE MALARIA VACCINE

描述(改编自调查人员摘要)：大量证据 在啮齿动物模型和人类志愿者身上显示出对 由疟疾子孢子感染可通过含有 环子孢子蛋白是子孢子的主要表面蛋白。 CS蛋白通过其区域II-+基序参与附着 寄生虫侵入肝细胞的步骤。调查员 发现另一种子孢子膜蛋白与凝血酶原蛋白相关 匿名蛋白(TRAP)，也是传染性所必需的 (-)寄生虫不表现出典型的滑行运动 不会感染蚊子的唾液腺或蚊子 哺乳动物宿主的肝脏。TRAP基因编码一种典型的膜 具有多肽锚定和细胞质结构域的蛋白质。N端子 陷阱区域包含大约220个残基模块，该模块 与在一个或多个中发现的A结构域(或整合素的I结构域)同源 复制在大量蛋白质中参与细胞-细胞、细胞-基质 互动。A区的高分辨晶体结构 整合素揭示了表面暴露的金属离子的存在 参与蛋白质识别的粘附点(MIDAS) 配基。长期目标是分析结构/功能 属性，并利用这些信息来提高陷阱的有效性 CS疫苗。其具体目的是：1)通过基因打靶获得 伯氏疟原虫品系在氨基酸陷阱中存在微妙突变 推测是为了配位金属离子，以及带有缺失的P.berghei线 TRAP的细胞质结构域。2)研究这些突变体的表型。 蚊媒和哺乳动物宿主中的寄生虫。3)表达原汁原味 和伯氏假单胞菌A区的突变形式，研究它们的能力 结合金属离子，抑制子孢子体外侵袭肝细胞。 4)开发可诱导特异性抗体的合成疫苗 表面暴露的环路可能位于A的MIDAS的边缘 约氏拟青霉圈闭的属性域。

DESCRIPTION (adapted from investigators abstract): A large body of evidence in rodent models and in human volunteers shows that protection against infection by malaria sporozoites can be obtained by vaccines containing the circumsporozoite (CS) protein, the major surface protein of sporozoites. Through its region II-plus motif, CS protein participates in the attachment step of the invasion of hepatocytes by the parasites. The investigator finds that another sporozoite membrane protein, the thrombospondin-related anonymous protein (TRAP), is additionally required for infectivity: TRAP (-) parasites do not exhibit the characteristic gliding motility of Apicomplexa, and do not infect the salivary glands of mosquitoes or the liver of the mammalian host. The TRAP gene encodes a typical membrane protein with a peptide anchor and a cytoplasmic domain. The N-terminal region of TRAP contains an approximately 220 residue module that is homologous to the A domains (or I domain of integrins) found in one or more copies in a large number of proteins involved in cell-cell, cell-matrix interactions. The high resolution crystal structure of A domains of integrins reveals the presence of a surface exposed metal ion dependent adhesion site (MIDAS) that participates in the recognition of the protein ligands. The long term objectives are to analyze the structural/functional properties of TRAP, and to use this information to improve the efficacy of CS vaccines. The specific aims are 1) to obtain by gene targeting Plasmodium berghei lines with subtle mutations in TRAP of amino acids that are presumed to coordinate metal ion, and P. berghei lines with deletions in the cytoplasmic domain of TRAP. 2) to study the phenotype of these mutant parasites in the mosquito vector and mammalian host. 3) to express native and mutant forms of the A domain of P. berghei TRAP, study their ability to bind metal ions, and to inhibit sporozoite invasion of hepatocytes in vitro. 4) to develop synthetic vaccines that elicit specific antibodies against surface-exposed loops presumably located at the edges of the MIDAS of the A domain of P. yoelii TRAP.