MOLECULAR GENETIC ANALYSIS OF MALARIA ANTIGENS

疟疾抗原的分子遗传学分析

• 批准号: 6689626
• 负责人: Kim C Williamson
• 金额: $ 26.6万
• 依托单位: LOYOLA UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6689626
• 关键词: Plasmodium falciparum; communicable disease transmission; developmental genetics; disease vectors; gene complementation; gene expression; gene targeting; genetic transcription; malaria; molecular cloning; nuclear runoff assay; protein structure function; protozoal antigen; sex differentiation; transfection

DESCRIPTION: Malaria is one of the major causes of mortality and morbidity worldwide. To continue to formulate new, more effective control strategies, a detailed understanding of the parasite life cycle on the molecular level is critical. The transition from the asexual cycle to sexual differentiation is required for malaria transmission in the field. Once sexual development is initiated, the parasite no longer undergoes asexual replication and dies several days after reaching maturity if not taken up in a blood meal by a mosquito. Once ingested by a mosquito, gametocytes are triggered to emerge from the RBC and, if fertilized, develop into infectious sporozoites. The molecular mechanisms involved in this complex differentiation pathway are largely unknown, although it has been characterized morphologically and several sexual-stage specific proteins have been identified. Antibodies specific for sexual-stage surface molecules, including Pfs230 and Pfs48/45, have been shown to block the ability of the parasite to infect mosquitoes, thus blocking, malaria transmission. These proteins have been studied for many years as vaccine candidates but their actual functions remain unknown. Both Pfs230 and Pfs48/45 are expressed only during sexual differentiation in the human host and through the transition of the parasite into the mosquito midgut. Our hypothesis is that Pfs230 & Pfs48/45 play a significant role in the development of gametocytes into viable fertilized zygotes and that the regulation of their expression is important to their function. As a first step toward the elucidation of the function of Pfs230 & Pfs48/45, their expression will be inhibited by targeted-gone disruption (Specific aim 1) and the effects this has on gametocyte & gamete differentiation will be evaluated (Specific aim 2). Transformed parasites will be selected by drug- resistance, cloned, and analyzed for disruption of each targeted gene. The morphology and gene expression pattern of transformants and wild-type parasites will be compared throughout sexual differentiation. To confirm that any changes observed are due to disruption of the targeted-gene, expression will be restored by complementation and the phenotype reanalyzed. The biological role of Pfs230 & Pfs48/45 is also affected by the time course and level of their expression. To begin to evaluate this, the elements regulating their transcription will be analyzed (Specific aim 3). The time course of MRNA production will be evaluated and the 5' regulatory elements that are involved in stage- specific regulation will be mapped by testing their ability to drive stage-specific expression of chloramphenicol acetyltransferase. The regulatory regions identified will be used to test for nuclear factor binding, to identify similar regions in other genes, and to construct transformation plasmids containing stage-specific, inducible promoters.

描述：疟疾是死亡率和发病率的主要原因之一 全世界。继续制定新的，更有效的控制策略，一个 对分子水平上寄生虫生命周期的详细理解是 批判的。从无性周期到性别差异的过渡是 在现场传播疟疾所必需的。一旦性发展是 寄生虫不再经历无性复制并死亡 如果不在血液中吸收成熟后的几天， 蚊子。一旦被蚊子摄入，配子细胞就会触发 加拿大皇家银行（RBC），如果受精，则会发展为传染性的孢子菌。分子 这种复杂分化途径涉及的机制在很大程度上是 未知，尽管它在形态学上已经表征了，有几个 已经确定了性阶段的特定蛋白质。特定的抗体 已经显示了包括PFS230和PFS48/45在内的性阶段表面分子 阻止寄生虫感染蚊子的能力，从而阻止，阻塞， 疟疾传播。这些蛋白质已经研究了多年 候选疫苗但其实际功能仍然未知。 PFS230和PFS48/45均仅在性别差异期间表达 人类宿主，通过寄生虫向蚊子过渡 Midgut。我们的假设是PFS230＆PFS48/45在 将配子细胞开发为可行的受精zygotes，并 调节其表达对其功能很重要。作为第一步 为了阐明PFS230和PFS48/45的功能，它们的表达 将受到靶向基因破坏（特定的目标1）和影响的影响 将评估这对配子细胞和配子差异化（具体目的 2）。转化后的寄生虫将通过耐药性，克隆和 分析了每个靶向基因的破坏。形态和基因 将比较转化体和野生型寄生虫的表达模式 整个性别差异。确认观察到的任何变化应到期 为了破坏目标基因，表达将由 互补和重新分析的表型。 PFS230＆ PFS48/45也受其表达的时间过程和水平的影响。到 开始评估这一点，调节其转录的要素将是 分析（特定目标3）。将评估mRNA产生的时间过程 以及涉及分期特定调节的5'调节元素 通过测试其驱动特定阶段特异性表达的能力来映射 氯霉素乙酰转移酶。确定的监管区将是 用于测试核因子结合，以识别其他区域 基因，并构建包含特定阶段的转化质粒， 诱导启动子。

项目成果

Approaches to malaria vaccine development using the retrospectroscope.

使用回顾镜开发疟疾疫苗的方法。

• DOI: 10.1128/iai.00122-09
• 发表时间: 2009
• 期刊: Infection and immunity
• 影响因子: 3.1
• 作者: Sardá,Vanessa;Kaslow,DavidC;Williamson,KimC
• 通讯作者: Williamson,KimC

Author Correction: The Plasmodium falciparum male gametocyte protein P230p, a paralog of P230, is vital for ookinete formation and mosquito transmission.

作者更正：恶性疟原虫雄配子体蛋白 P230p 是 P230 的旁系同源物，对于动合子的形成和蚊子传播至关重要。

• DOI: 10.1038/s41598-019-43505-y
• 发表时间: 2019
• 期刊: Scientific reports
• 影响因子: 4.6
• 作者: Marin-Mogollon,Catherin;vandeVegte-Bolmer,Marga;vanGemert,Geert-Jan;vanPul,FionaJA;Ramesar,Jai;Othman,AhmadSyibli;Kroeze,Hans;Miao,Jun;Cui,Liwang;Williamson,KimC;Sauerwein,RobertW;Janse,ChrisJ;Khan,ShahidM
• 通讯作者: Khan,ShahidM

Malaria parasites form filamentous cell-to-cell connections during reproduction in the mosquito midgut.

• DOI: 10.1038/cr.2010.176
• 发表时间: 2011-04
• 期刊: Cell research
• 影响因子: 44.1