Mechanism of cryptococcal fitness, innate defense subversion, and the adaptive immune skewing in lungs

隐球菌适应性机制、先天防御颠覆和肺部适应性免疫偏差

• 批准号: 10696521
• 负责人: Kristie D Goughenour
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2028-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10696521
• 关键词: Affect; Alveolar; Alveolar Macrophages; Anabolism; Animals; Antifungal Agents; Bacteria; Biological; Cells; Collectins; Cryptococcus; Cryptococcus neoformans; Cryptococcus neoformans infection; Data; Development; Disaccharides; Excision; Exposure to; Future; Goals; Health; Host Defense; Human; Iatrogenesis; Immune; Immune Evasion; Immune response; Immune system; Immunologic Memory; Immunologic Stimulation; In complete remission; Infection; Innate Immune Response; Integration Host Factors; Intercept; Kinetics; Laboratories; Learning; Lung; Lung diseases; Lung infections; Mammalian Cell; Mediating; Memory; Mentors; Microbe; Modeling; Molecular; Morbidity - disease rate; Mus; Mycoses; Outcome; Pathogenesis; Pathway interactions; Phagocytosis; Process; Production; Pulmonary Surfactant-Associated Protein A; Pulmonary Surfactant-Associated Protein D; Research; Research Personnel; Research Training; Risk; Role; Stress; T-Lymphocyte; Training; Training Programs; Trehalose; Veterans; Virulence; Virulence Factors; Work; antimicrobial; arm; cancer therapy; career; career development; fitness; fungicide; fungus; high risk; improved; inhibitor; inorganic phosphate; insight; microbial; mortality; mouse model; multidisciplinary; neutrophil; new technology; novel; opportunistic pathogen; pathogen; pathogenic fungus; post-doctoral training; programs; recruit; response; skills; sugar; surfactant

Cryptococcus neoformans (C. neo), is one of the most significant fungal pathogens worldwide. However, much is still unknown on how it interacts with the host to evade and subvert the immune response. Here we propose to study the biological effects of intercepting the trehalose sugar biosynthetic pathway, which our data suggest affects interactions of cryptococcus with multiple lines of host defenses and could serve as an “Achilles heel” for the fungus. Trehalose-6-phosphate synthase (TPS1) catalyzes the first step in the biosynthetic pathway to generate trehalose, a disaccharide that canonically protects C. neo (and other microbes) against stress, which is not synthesized or required by mammalian cells. TPS1 has been described as a virulence factor for C. neo in multiple animal infection models, but the mechanistic underpinnings are undefined. We propose to mechanistically uncover how TPS1-deletion alters fungal-host interactions to drive this increased fungal control. Our preliminary data show that in murine models of pulmonary infection, trehalose-deficient C. neo (tps1Δ) is very rapidly cleared due to improved immune protection. As such, we hypothesize that cryptococcal TPS1 is required to protect the fungus against all 3 lines of pulmonary host defenses via (1) interference with the local resident defenses; (2) the recruitment/activation of the innate immune cells for early fungal control, and (3) modulation of the adaptive memory responses. We propose that trehalose is required to protect C. neo against innate factors in the alveolar space, such as surfactants. Our preliminary data support a role for the surfactant proteins A and D in trehalose-deficient C. neo control (Aim 1). We also propose that the loss of trehalose facilitates rapid fungal clearance by resident innate immune cells, specifically neutrophils (Aim2). Further, our preliminary data suggest that the loss of Tps1-function by Cryptococcus results in an immunostimulation that supports the development of protective skewing and an adaptive immune memory response (Aim 3). This improved the level of immunoprotection supports that targeting the TPS pathway, apart from directly aiding the fungal removal, can induce long-term protective immune memory effects. Eventually, understanding how trehalose alters cryptococcal interactions with host defenses could support the development of a future class of broad antifungal inhibitors that could aid the treatment of multiple types of fungal infections. In summary, this work will provide novel context for how C. neo avoids pulmonary host defenses and how these interactions can be exploited. The studies proposed above make up the scientific basis for the VA CDA-2 program that will provide training and career development for Dr. Kristie Goughenour into an independent VA investigator. Dr. Goughenour completes the third year of her postdoctoral training in the Multidisciplinary T32 Research Training Program in Lung Disease. Her primary research focus is on host-pathogen interactions of pathogenic fungi in pulmonary infections. Her training has provided her with both the technical ability and theoretical framework to dissect both the human host factors and the microbial virulence mechanisms that interact to determine the outcomes of infections. This proposal builds upon her skills in molecular mechanisms of fungal pathogenesis and host responses to fungal pathogens to combine into unique expertise in host immune control of pulmonary fungal pathogens and novel mechanisms of fungal immune evasion. Dr. Goughenour will strengthen her expertise in different aspects of immune processes and learn several new technologies. Her mentoring team of 5 top experts in their respective fields has been carefully developed to provide expertise and career support while she transitions towards independence and to provide aid on the proposed studies.

新型隐球菌（C. neo）是全世界最重要的真菌病原体之一。 然而，关于它如何与宿主相互作用以逃避和破坏免疫反应，目前仍不清楚。 在这里，我们建议研究拦截海藻糖生物合成途径的生物学效应，该途径 我们的数据表明影响隐球菌与多道宿主防御线的相互作用，并且可以作为 真菌的“致命弱点”是海藻糖-6-磷酸合酶 (TPS1) 催化第一步。 产生海藻糖的生物合成途径，海藻糖是一种典型地保护新梭菌（和其他 微生物）对抗压力，TPS1 不是哺乳动物细胞合成或需要的。 在多种动物感染模型中作为 C. neo 的毒力因子，但其机制基础是 我们建议机械地揭示TPS1删除如何改变真菌-宿主相互作用以驱动。 这增加了真菌控制。 我们的初步数据表明，在肺部感染的小鼠模型中，海藻糖缺乏的 C. neo 由于免疫保护的改善，(tps1Δ) 被非常迅速地清除，因此，我们对隐球菌进行了研究。 TPS1 需要通过以下方式保护真菌免受肺部宿主防御的所有 3 条防线：(1) 干扰 (2) 招募/激活先天免疫细胞以进行早期真菌控制， (3) 适应性记忆反应的调节我们提出需要海藻糖来保护 C. neo。 对抗肺泡腔中的先天因素，例如表面活性剂，我们的初步数据支持了其作用。 海藻糖缺陷 C. neo 对照中的表面活性蛋白 A 和 D（目标 1）。 海藻糖促进固有先天免疫细胞（特别是中性粒细胞）快速清除真菌 (Aim2)。 此外，我们的初步数据表明，隐球菌 Tps1 功能的丧失会导致 支持保护性偏差和适应性免疫记忆发展的免疫刺激 反应（目标 3），这提高了免疫保护水平，支持靶向 TPS 途径。 直接帮助去除真菌，最终可以诱导长期的保护性免疫记忆效应。 了解海藻糖如何改变隐球菌与宿主防御的相互作用可以支持 开发未来一类广泛的抗真菌抑制剂，可以帮助治疗多种类型的真菌 总之，这项工作将为 C. neo 如何避免肺部感染提供新的背景。 宿主防御以及如何利用这些相互作用。 上述研究构成了 VA CDA-2 计划的科学基础，该计划将提供 将 Kristie Goughenour 博士培养为一名独立的 VA 调查员。 Goughenour 在多学科 T32 研究培训中完成了第三年的博士后培训 她的肺部疾病项目主要研究病原真菌的宿主与病原体的相互作用。 她的培训为她提供了处理肺部感染的技术能力和理论框架。 剖析相互作用的人类宿主因素和微生物毒力机制，以确定 该提案建立在她在真菌发病机制分子机制方面的技能基础上。 和宿主对真菌病原体的反应，结合成肺部宿主免疫控制的独特专业知识 真菌病原体和真菌免疫逃避的新机制将增强她的能力。 她的指导团队在免疫过程的不同方面拥有专业知识，并学习多种新技术。 精心培养了5位各自领域的顶尖专家，提供专业知识和职业支持 同时她向独立过渡并为拟议的研究提供援助。