Granzyme and Granulysin Mediated Death of Trypanosoma cruzi

颗粒酶和颗粒溶素介导的克氏锥虫死亡

• 批准号: 9104713
• 负责人: RICARDO TOSTES GAZZINELLI
• 金额: $ 64.57万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-01 至 2021-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9104713
• 关键词: Acute; Affect; Apoptosis; Arrhythmia; Bacteria; Blood Transfusion; CD8-Positive T-Lymphocytes; CD8B1 gene; Cardiac; Cardiomyopathies; Cause of Death; Cell Death; Cell membrane; Cells; Cessation of life; Chagas Disease; Cholesterol; Chronic; Cleaved cell; Complex; Country; Cytoplasmic Granules; Cytotoxic T-Lymphocytes; Data; Electron Transport; Enzymes; Goals; Granzyme; Host resistance; Human; Immigration; Immune; Immune response; Infection; Inflammatory Response; Interferons; Killer Cells; Latin America; Leishmania major; Life; Listeria monocytogenes; Lymphocyte; Mammalian Cell; Mammals; Mediating; Membrane; Modeling; Mus; Natural Immunity; Natural Killer Cells; Organ Transplantation; Outcome; Parasites; Pathology; Pathway interactions; Patients; Peptide Hydrolases; Phagocytosis; Pharmaceutical Preparations; Plasma; Play; Principal Investigator; Process; Proteins; Public Health; Rodent; Role; Serine Protease; Severities; Staging; Superoxides; Surrogate Markers; Synapses; T cell response; T-Lymphocyte; Testing; Time; Tissues; Toxic Megacolon; Toxoplasma gondii; Transgenes; Transgenic Mice; Trypanosoma cruzi; VDAC1 gene; Vaccinated; Vaccination; Vaccine Therapy; Vaccines; Virulence Factors; Wild Type Mouse; adaptive immunity; base; cell killing; cytotoxic; disorder risk; drug development; fungus; granulysin; human disease; in vivo; insight; killings; macrophage; neglect; novel; pathogen; perforin; prevent; programs; prophylactic; public health relevance; transmission process; vaccine development; vaccine-induced immunity

 DESCRIPTION (provided by applicant): When killer lymphocytes recognize cells infected with intracellular pathogens, they release their cytotoxic granule contents to induce apoptosis of the infected target cell. However, what happens to intracellular parasites during this process is unclear. Host cell apoptosis is triggered by cytotoxic granule proteases (granzymes, Gzm), delivered into the target cell by the cholesterol-dependent membrane perturbing protein, perforin (PFN). Cytotoxic granules of humans and some other mammals, but not rodents, contain another pore-forming protein, granulysin (GNLY), which preferentially disrupts cholesterol-poor bacterial, fungal and parasite membranes. We recently found that when human killer lymphocytes recognize bacteria-infected cells, they rapidly kill intracellular bacteria. GNLY delivers Gzms into bacteria where they proteolytically attack bacterial electron transport chain complex I to generate toxic superoxide anion and also proteolytically destroy bacterial oxidative defense enzymes. Preliminary data show that GNLY also delivers Gzms into protozoan parasites (Trypanosoma cruzi, Toxoplasma gondii, Leishmania major), which are rapidly killed, also in a superoxide-dependent manner. Destruction of intracellular parasites relies on the concerted action of all three cytotoxic effector molecules - Gzms, PFN and GNLY. Mice that express a GNLY transgene in killer lymphocytes are able to survive a T. cruzi challenge that is lethal to wild-type (WT) mice. This proposal uses T. cruzi as a model to investigate the hypothesis that GNLY, Gzm and PFN-mediated killing of intracellular protozoan parasites provides strong immune protection against intracellular parasites. We hypothesize that T. cruzi amastigotes are killed before the host cell, which limits the spread of infection. We also hypothesize that killer cells rapidly induce programs of cell death in T. cruzi that share some features with death pathways activated by Gzms in mammalian cells or bacteria. We also hypothesize that direct parasite killing helps control acute infection, enhance vaccine protection and reduce the chagasic pathology of chronic infection. This proposal joins the expertise of two principal investigators, who are leaders in studying (1) how killer cells destroy infected host cels and their pathogens and (2) the immune response to T. cruzi. The aims of the proposal are to define the features of killer cell-mediated parasite death, identify T. cruzi Gzm substrates that are important in causing death and explore how direct parasite killing contributes to immune defense by comparing infection in WT mice that do not express GNLY with GNLY-transgenic mice.

 描述（由申请方提供）：当杀伤淋巴细胞识别被细胞内病原体感染的细胞时，它们释放其细胞毒性颗粒内容物以诱导感染的靶细胞凋亡。然而，在这个过程中细胞内寄生虫会发生什么尚不清楚。宿主细胞凋亡由细胞毒性颗粒蛋白酶（颗粒酶，Gzm）触发，通过胆固醇依赖性膜扰动蛋白穿孔素（PFN）递送到靶细胞中。人类和一些其他哺乳动物的细胞毒性颗粒，但不是啮齿动物，含有另一种成孔蛋白，颗粒溶素（GNLY），它优先破坏胆固醇贫乏的细菌，真菌和寄生虫膜。我们最近发现，当人类杀伤淋巴细胞识别细菌感染的细胞时，它们会迅速杀死细胞内的细菌。GNLY将Gzms递送到细菌中，在那里它们蛋白水解攻击细菌电子传递链复合物I以产生有毒的超氧阴离子，并且还蛋白水解破坏细菌氧化防御酶。初步数据显示，GNLY还将Gzms递送到原生动物寄生虫（克氏锥虫、刚地弓形虫、硕大利什曼原虫）中，这些寄生虫也以超氧化物依赖的方式被迅速杀死。细胞内寄生虫的破坏依赖于所有三种细胞毒性效应分子- Gzms、PFN和GNLY的协同作用。在杀伤淋巴细胞中表达GNLY转基因的小鼠能够在T. cruzi攻击，其对野生型（WT）小鼠是致命的。该建议使用T. cruzi作为模型来研究GNLY、Gzm和PFN介导的细胞内原生动物寄生虫的杀伤提供针对细胞内寄生虫的强免疫保护的假设。我们假设T.克氏无鞭毛体在宿主细胞之前被杀死，这限制了感染的传播。我们还假设，杀伤细胞迅速诱导T细胞死亡程序。cruzi，与哺乳动物细胞或细菌中Gzms激活的死亡途径有一些共同的特征。我们还假设，直接杀死寄生虫有助于控制急性感染，增强疫苗的保护作用，减少慢性感染的chagerous病理。这一建议结合了两位主要研究者的专业知识，他们是研究（1）杀伤细胞如何摧毁受感染的宿主及其病原体和（2）对T。克鲁兹该提案的目的是定义杀伤细胞介导的寄生虫死亡的特征，鉴定T。cruzi Gzm底物在导致死亡中起重要作用，并通过比较不表达GNLY的WT小鼠与GNLY转基因小鼠的感染，探索直接杀死寄生虫如何有助于免疫防御。