A Novel MAPK family in T. gondii

弓形虫中一个新的 MAPK 家族

• 批准号: 7408234
• 负责人: Tyler J. Curiel
• 金额: $ 6.14万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7408234
• 关键词: RNA interference; SDS polyacrylamide gel electrophoresis; Toxoplasma gondii; autoradiography; drug discovery /isolation; drug resistance; enzyme activity; enzyme inhibitors; gene expression; gene targeting; genetically modified animals; laboratory mouse; microorganism growth; mitogen activated protein kinase; parasite infection mechanism; pharmacology; polymerase chain reaction; virulence; western blottings

DESCRIPTION (provided by applicant): We recently cloned the first T. gondii MAP kinase, MAPK1-Tg, which acts as a stress MAPK and has 40% homology to human p38 MAPK. MAPK1-Tg is expressed as the full-length 58 kDa protein in tachyzoites, and is the first member of a novel MAPK family. T. gondii tachyzoites expressing a dominant-negative MAPK1-Tg replicated significantly more slowly than parental parasites in vitro, and expressed significantly more bradyzoite antigens. Most strikingly, these tachyzoites were remarkably attenuated in mouse virulence. These data implicate MAPK1-Tg in control of tachyzoite proliferation, stage differentiation and virulence. We previously showed that pyridinylimidazole drugs designed to block human p38 MAPK activation also blocked T. gondii replication in vitro, cured T. gondii-infected mice, and induced stage differentiation in vitro. Human p38 MAPK inhibitors block MAPK1-Tg activity in vitro. We hypothesize that p38 MAPK inhibitors treat T. gondii infection through inhibition of MAPK1-Tg. This proposal will study MAPK1-Tg with two fundamental objectives: i) to exploit MAPK1-Tg as a novel drug discovery target, and ii) to use MAPK1-Tg as a tool to increase our understanding of T. gondii biology. 67657 is the prototypical p38 MAPK inhibitor used. It was safe in human Phase I trials in arthritis, and could be translated into a human clinical trial as an anti-parasitic agent rapidly. MAPK homologues with structural features of MAPK1-Tg were identified in genomic databases for Plasmodium, Leishmania and Trypanosoma. We hypothesize that parasite MAPKs represent novel, broad spectrum drug development target. Finally, T. gondii is a category B bioterror agent. Thus, these discoveries could lead to novel treatment approaches to combating bioterror. Our Specific aims are: 1 Test hypotheses regarding how MAPK1-Tg regulates replication and stage differentiation. The development of reagents to detect endogenously produced total and active MAPK1-Tg in wild-type parasites, and the development of recombinant parasites with dominant-negative MAPK1-Tg now permit definitive testing of hypotheses regarding how MAPK1-Tg activation regulates tachyzoite replication and stage differentiation, and effects on the cell cycle regulation. Test the hypothesis that 67657 blocks MAPK1-Tg activation. These studies help elucidate factors controlling parasite virulence. 2 Test the hypothesis that blocking MAPK1-Tg activation is a mechanism of therapeutic action of p38 MAPK inhibitors. 3 Test the hypothesis that blocking MAPK1-Tg augments efficacy of anti-Toxoplasma therapies in vivo.

描述（由申请人提供）：我们最近克隆了第一个T. gondii Map激酶MAPK1-TG，它充当压力MAPK，与人P38 MAPK具有40％同源性。 MAPK1-TG表示为tachyzoites中的全长58 kDa蛋白，并且是新型MAPK家族的第一个成员。表达显性阴性MAPK1-TG的Gondii tachyzoites复制的复制明显较慢，比父母的寄生虫在体外慢得多，并且表达明显更多的曲霉剂抗原。最引人注目的是，这些速二鼠在小鼠毒力中明显减弱。 这些数据暗示MAPK1-TG控制了速氮岩增殖，阶段分化和毒力。 我们先前表明，旨在阻断人p38 MAPK激活的吡啶基咪唑药在体外还阻断了gondii的复制。人p38 MAPK抑制剂在体外阻断MAPK1-TG活性。我们假设p38 MAPK抑制剂通过抑制MAPK1-TG治疗T. gondii感染。该提案将以两个基本目标研究MAPK1-TG：i）利用MAPK1-TG作为一种新的药物发现靶标，ii）使用MAPK1-TG作为一种工具来增强我们对T. gondii生物学的理解。 67657是使用的原型p38 MAPK抑制剂。它在人类I期关节炎试验中是安全的，可以迅速将人类临床试验转化为人类临床试验。 MAPK同源物具有MAPK1-TG的结构特征，在疟原虫，利什曼原虫和锥虫瘤的基因组数据库中鉴定出来。我们假设寄生虫MAPK代表了新型，广泛的药物开发目标。最后，T。Gondii是B类Bioterror剂。因此，这些发现可能会导致对抗生物eRROR的新型治疗方法。我们的具体目的是：1个关于MAPK1-TG如何调节复制和分阶段分化的检验假设。目前，野生型寄生虫中检测内源性产生的总和MAPK1-TG的试剂的开发，以及具有显性阴性​​MAPK1-TG的重组寄生虫的开发允许对MAPK1-TG激活如何调节Tachyzoite的重复和阶段分化和对细胞的效果的假设进行明确测试。检验67657阻断MAPK1-TG激活的假设。这些研究有助于阐明控制寄生虫毒力的因素。 2检验以下假设：阻断MAPK1-TG激活是p38 MAPK抑制剂的治疗作用机制。 3检验以下假设：阻止MAPK1-TG增强体内抗氧化杀菌疗法的功效。