Regulation of cyst formation in the AIDS opportunistic pathogen Toxoplasma

艾滋病机会病原体弓形虫包囊形成的调节

• 批准号: 10515665
• 负责人: William J Sullivan
• 金额: $ 23.01万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-11-01 至 2024-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10515665
• 关键词: Acetylation; Acetyltransferase; Acquired Immunodeficiency Syndrome; Address; Binding; Biological Assay; Biological Models; Brain; Cells; Chronic; Clinical; Co-Immunoprecipitations; Complex; Cyst; Data; Development; Differentiation and Growth; EIF-2alpha; Eukaryotic Initiation Factor-2; Felis catus; Food Contamination; Genes; HIV/AIDS; Human; Immune; Immune response; In Vitro; Individual; Infection; Knowledge; Life; Lysine; Messenger RNA; Molecular; Mus; Muscle; Mutation Analysis; Myocardium; Open Reading Frames; Opportunistic Infections; Parasites; Patients; Pharmaceutical Preparations; Phosphorylation; Play; Polyribosomes; Population; Post-Transcriptional Regulation; Post-Translational Protein Processing; Process; Proliferating; Proteins; Recurrence; Regulation; Regulatory Element; Reporter; Reporting; Role; Skeletal Muscle; Testing; Therapeutic Intervention; Tissues; Toxoplasma; Toxoplasma gondii; Toxoplasmosis; Transcript; Transcription Coactivator; Translations; Water; Yeasts; chromatin remodeling; clinically relevant; gene network; insight; mRNA Translation; microbial; novel; opportunistic pathogen; posttranscriptional; promoter; recruit; response; transcription factor; transmission process; yeast two hybrid system

PROJECT SUMMARY Toxoplasma gondii is an intracellular protozoan parasite that poses a major threat to patients with HIV/AIDS. The replicative stage (tachyzoite) develops into a latent stage (bradyzoite) that resides inside host cells as cysts in brain, heart, and skeletal muscle tissues. Tissue cysts remain in the host for life, as they are impervious to the immune response and currently approved drugs, and give rise to recurrent reactivation of infection in immune compromised patients. Despite its clinical importance, little is known about the complex transition from the tachyzoite to bradyzoite stage. A key transcription factor called BFD1 was recently discovered that is necessary and sufficient for cyst formation in vitro and in mice, but we currently know nothing about the regulation this factor. We will fill this gap in our knowledge building from our strong preliminary findings that BFD1 is subject to tight regulatory control at the post- transcriptional level. We have shown that translation of BFD1 mRNA is enhanced more than 30- fold in response to TgIF2α phosphorylation. Consistent with this observation is the presence of numerous upstream open reading frames (uORFs) in the 5’-leader of BFD1 mRNA. Aim 1 will test our hypothesis that these uORFs play a key role in the preferential translation of BFD1 that occurs in response to bradyzoite induction. In addition to translational control, we have additional preliminary data suggesting that BFD1 is regulated at the protein level through lysine acetylation. Our acetylome analysis of tachyzoites found that BFD1 is acetylated at lysine 1720 (K1720) and that BFD1 was the top hit in a yeast two-hybrid screen performed with the lysine acetyltransferase TgGCN5a. Aim 2 will test our hypothesis that TgGCN5a regulates BFD1 through K1720 acetylation using co-immunoprecipitation assays and mutational analysis. Completion of these two aims will reveal critical new insights into the post-transcriptional mechanisms that govern BFD1 activity, which promise to serve as novel points of therapeutic intervention to treat this devastating opportunistic infection in HIV/AIDS patients.

项目概要 弓形虫是一种细胞内原生动物寄生虫，对患者构成重大威胁 艾滋病毒/艾滋病的复制阶段（速殖子）发展为潜伏阶段（缓殖子）。 组织囊肿存在于宿主细胞内，如脑、心脏和骨骼肌组织中的囊肿。 终生留在宿主体内，因为它们不受免疫反应的影响，目前 批准，并引起免疫受损患者感染反复再激活的药物 尽管它具有临床重要性，但人们对这一复杂的转变知之甚少。 最近发现了一种称为 BFD1 的关键转录因子。 这对于体外和小鼠体内囊肿的形成是必要且充分的，但我们目前知道 我们将通过我们的知识建设来填补这一空白。 强有力的初步调查结果表明，BFD1 在上市后受到严格的监管控制 我们已经表明 BFD1 mRNA 的翻译增强超过 30- 响应 TgIF2α 磷酸化的折叠与此观察一致的是存在 BFD1 mRNA 的 5’-前导序列中存在大量上游开放阅读框 (uORF)。 检验我们的假设，即这些 uORF 在 BFD1 的优先翻译中发挥关键作用 除了翻译控制之外，我们还有对缓殖子诱导的反应。 其他初步数据表明 BFD1 通过赖氨酸在蛋白质水平上受到调节 我们对速殖子的乙酰化分析发现 BFD1 在赖氨酸 1720 处被乙酰化。 (K1720) 并且 BFD1 是用赖氨酸进行的酵母双杂交筛选中的最佳选择 目标 2 将检验我们的假设：TgGCN5a 调节 BFD1。 使用免疫共沉淀分析和突变分析通过 K1720 乙酰化。 这两个目标的完成将揭示对转录后的重要新见解 控制 BFD1 活性的机制有望成为治疗的新点 干预措施来治疗艾滋病毒/艾滋病患者中这种毁灭性的机会性感染。

项目成果

mRNA cap-binding protein eIF4E1 is a novel regulator of Toxoplasma gondii latency.

mRNA 帽结合蛋白 eIF4E1 是弓形虫潜伏期的新型调节因子。

• 发表时间: 2023-10-09
• 作者: Holmes, Michael J;Bastos, Matheus S;Dey, Vishakha;Severo, Vanessa;Wek, Ronald C;Sullivan Jr, William J
• 通讯作者: Sullivan Jr, William J