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.

新生隐球菌（C. neo）是世界上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，仍有很多未知数。 在这里，我们建议研究阻断海藻糖糖生物合成途径的生物学效应， 我们的数据表明，影响隐球菌与多种宿主防御系统的相互作用， 真菌的致命弱点海藻糖-6-磷酸合酶（TPS 1）催化的第一步， 生物合成途径产生海藻糖，一种二糖，典型地保护C。neo（及其他） 微生物）对抗应激，这不是哺乳动物细胞合成或需要的。TPS 1已经被描述为 作为C. neo在多种动物感染模型中，但机制基础是 未定义。我们建议从机制上揭示TPS 1缺失如何改变真菌-宿主相互作用， 这增加了真菌控制。 我们的初步数据显示，在肺部感染的小鼠模型中，海藻糖缺陷型C。neo (tps1Δ）由于改善的免疫保护而被非常迅速地清除。因此，我们假设隐球菌 需要TPS 1来保护真菌抵抗肺部宿主防御的所有3条线，通过（1）干扰 局部固有防御;（2）先天免疫细胞的募集/激活用于早期真菌控制， 以及（3）适应性记忆反应的调制。我们认为海藻糖是保护C. neo 对抗肺泡腔中的先天因素，如表面活性剂。我们的初步数据支持的作用， 海藻糖缺乏C. neo对照（Aim 1）。我们还建议， 海藻糖促进固有免疫细胞，特别是嗜中性粒细胞（Aim 2）快速清除真菌。 此外，我们的初步数据表明，隐球菌Tps 1功能的丧失导致了 免疫刺激，支持保护性偏斜和适应性免疫记忆的发展 响应（目标3）。这提高了免疫保护水平，支持靶向TPS途径， 从直接帮助真菌清除，可以诱导长期的保护性免疫记忆效应。最后， 了解海藻糖如何改变隐球菌与宿主防御的相互作用， 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 真菌感染总之，这项工作将为C。neo避免肺部 主机防御以及如何利用这些交互。 上述研究为VA CDA-2项目提供了科学依据， Kristie Goughenour博士的培训和职业发展成为独立的VA调查员。博士 Goughenour在多学科T32研究培训中完成了博士后培训的第三年 在肺部疾病的计划。她的主要研究重点是病原真菌的宿主-病原体相互作用， 肺部感染她的培训为她提供了技术能力和理论框架， 剖析人类宿主因素和相互作用的微生物毒力机制， 感染的结果。这一建议建立在她的技能在分子机制的真菌发病机制 和宿主对真菌病原体的反应，使之联合收割机成为宿主免疫控制肺部感染的独特专长。 真菌病原体和真菌免疫逃避的新机制。古格诺医生会让她恢复体力 在免疫过程的不同方面的专业知识，并学习一些新技术。她的导师团队 5名各自领域的顶尖专家被精心培养，提供专业知识和职业支持 同时，她过渡到独立，并提供援助的建议研究。