The role of sex in the life cycle of Pneumocystis

性在肺孢子虫生命周期中的作用

• 批准号: 10047702
• 负责人: Melanie T Cushion
• 金额: --
• 依托单位: CINCINNATI VA MEDICAL CENTER RESEARCH
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-10-01 至 2022-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10047702
• 关键词: 3-Dimensional; Address; Aftercare; Anidulafungin; Arthritis; Aspergillus; Biological; Bone Marrow; Candida albicans; Caring; Caspofungin; Cell Cycle; Cell Wall; Cells; Chronic; Chronic Obstructive Airway Disease; Clinical; Data; Environment; Exposure to; Female; Gene Expression; Gene Expression Profile; Gene Expression Profiling; Genes; Goals; HIV; Human; Immune; Immunocompromised Host; Immunosuppression; Immunotherapy; Infection; Infection prevention; Knowledge; Length; Life Cycle Stages; Link; Lung; Malignant Neoplasms; Metabolic; Methods; Microscopic; Modeling; Mus; Partner in relationship; Patients; Pharmaceutical Preparations; Phase; Phenotype; Pneumocystis; Pneumocystis Infections; Pneumocystis carinii; Pneumonia; Population; Proliferating; Property; Reporting; Rheumatoid Arthritis; Role; Sexual Reproduction; Signal Transduction; Stress; Time; United States; Up-Regulation; Veterans; Withdrawal; Withholding Treatment; asexual; base; cancer diagnosis; chronic inflammatory disease; clinically relevant; coping mechanism; fungus; genetic signature; high risk; immunological status; immunosuppressed; infected vector rodent; male; military veteran; novel therapeutics; pathogenic fungus; polyglucosan; prevent; prophylactic; sex; sexual debut; targeted treatment; therapy duration; transcriptome; transcriptome sequencing; transmission process; treatment duration; tumor necrosis factor-alpha inhibitor

Pneumocystis spp. are obligate fungal pathogens that cause a fatal pneumonia (PCP) in immunocompromised hosts. Few drugs are effective against PCP and there have been no new therapies for its treatment in decades. Typically, PCP has been associated with patients infected with HIV, however, the fulminate pneumonia, PCP, and colonization with Pneumocystis jirovecii (the species infecting humans) are emerging clinical problems in newly susceptible populations in the general and veterans’ populations including bone marrow recipients; patients receiving chronic immunotherapy for rheumatoid arthritis and other chronic inflammatory diseases; and cancer chemo- and immunotherapies. The life cycle of Pneumocystis is suggested to contain both an asexual replication cycle and a sexual cycle involving mating with subsequent formation of asci containing 8 ascospores (1). During the previous Merit Review, we showed that echinocandin treatment of rodents infected with P. murina and P. carinii, which target β-1,3-D-glucan synthesis (BG), depleted the asci which contain BG but large numbers of non-BG expressing life cycle stages remained in the lungs and were unable to proliferate. We further demonstrated that anidulafungin and caspofungin could prevent infection in a prophylactic model, suggesting that formation of asci via the sexual cycle may be required for a productive infection (2). Analysis of gene expression profiles of P. murina in mice treated with anidulafungin, showed strong upregulation of genes associated with sexual replication, though the resulting infections were devoid of asci, the product of sexual reproduction, suggesting that P. murina attempted to undergo sexual replication, but could not due to a lack of BG. Based on these data, we posit that asci, and thus sexual replication, is required to facilitate progression through the life cycle leading to a productive infection. We further posit that presence of asci is required for transmission of Pneumocystis infection. In the present proposal, we will explore 2 critical, but unanswered questions that will lead to a deeper knowledge of the life cycle of Pneumocystis, and also suggest potential vulnerabilities for targeted treatment concomitant with anidulafungin therapy: (1) Is sexual replication required for completion of the life cycle of Pneumocystis? Tracking of the replication status of P. murina during prolonged treatment with anidulafungin by global gene analysis, BG content, and microscopic methods will reveal whether the non-BG expressing forms numbers remain: 1) static over time, 2) increase, or 3) decrease; suggesting: 1) the lack of BG blocks replication; 2) that an asexual or alternative replication phase permits survival of the fungi; or 3) the lack of sexual replication results in elimination of the infection. (2) Can sexual replication rebound after cessation of prolonged anidulafungin treatment? Mice will be treated with anidulafungin for up to 8 weeks, with 2 cessation time points. Mice in the cessation groups will be tracked for microscopic, BG content, and gene expression evidence of asci formation and return of the pneumonia while remaining under immunosuppression. Mice in the treated and cessation groups will be evaluated for their ability to transmit the infection and the critical number of asci needed for transmission. All studies will be conducted in male and female mice, recognizing sex as a biological variable. The echinocandins are clinically available in the United States. Current monotherapy with any echinocandin for PCP is not warranted as withdrawal can result in return of the pneumonia. The results of the proposed studies will have immediate clinical relevance by determining the length of time viable Pneumocystis can remain in the lungs with concurrent anidulafungin treatment, providing a rationale for duration of therapy with eradication as the goal. They will also identify whether immunosuppressed mice can transmit the infection after withdrawal of anidulafungin and if there is a critical number of asci needed. The studies will also elaborate the life cycle of Pneumocystis and suggest new target strategies.

气囊属。是在引起致命性肺炎（PCP）的强制性真菌病原体 免疫功能低下的宿主。很少有药物对PCP有效，并且没有新的疗法 几十年来的治疗。通常，PCP与感染HIV的患者相关，但是， 肺炎，PCP和定植，肺炎藻（Jirovecii）（感染的人类）正在出现 一般和退伍军人种群中新易感人群的临床问题，包括骨骼 骨髓接收者；接受类风湿关节炎和其他慢性的慢性免疫疗法的患者 炎症性疾病；以及癌症化学和免疫疗法。建议肺炎的生命周期 既包含无性复制周期和性周期，涉及交配，随后形成 ASCI包含8个子孢子（1）。在先前的优异审查中，我们表明了对 啮齿动物感染了P. murina和P. carinii，靶向β-1,3-d-Glucan合成（BG），耗尽了ASCI 其中包含BG，但大量的非BG表达生命周期阶段仍保留在肺部，并且是 我们进一步证明了Anidulafungin和Caspofungin可以防止感染 预防模型，表明产品可能需要通过性周期形成ASCI 感染（2）。分析用Anidulafungin治疗的小鼠中穆拉纳的基因表达谱分析，表明很强 与性复制相关的基因上调，尽管所产生的感染没有ASCI， 有性繁殖的产物，表明P. Murina试图进行性复制，但不能 由于缺乏BG。基于这些数据，我们认为ASCI并因此需要进行性复制才能促进 通过生命周期的发展，导致生产性感染。我们进一步认为ASCI的存在是 肺炎胸膜感染的传播所必需的。在本提案中，我们将探索2个关键，但 未解决的问题将导致更深入了解肺囊肿的生命周期，也建议 与Anidulafungin治疗相关的有针对性治疗的潜在脆弱性： （1）完成肺炎藻的生命周期是否需要性复制？跟踪 通过全球基因分析，BG长时间治疗期间，P。Murina在长期治疗过程中的复制状态 内容和微观方法将揭示非BG表达形式数字是否保留：1）静态 随着时间的流逝，2）增加或3）减少；建议：1）缺乏BG块复制； 2）无性或 替代复制阶段允许真菌存活；或3）缺乏性复制导致紧急情况 感染。 （2）停止延长Anidulafungin治疗后，性复制可以反弹吗？老鼠会 用Anidulafungin处理长达8周，并有2个停止时间点。戒烟组中的小鼠将是 跟踪微观，BG含量和基因表达的ASCI形成和返回的基因表达证据 肺炎，同时保持在免疫抑制下。治疗和戒烟组中的小鼠将是 评估了它们传输感染的能力和传播所需的ASCI的临界数。全部 研究将在男性和雌性小鼠中进行，将性别视为生物学变量。 echinocandins在美国临床上可用。当前的单一疗法与任何echinocandin 因为pcp不保证，因为戒断会导致肺炎恢复。拟议研究的结果 通过确定时间长度可行的气囊可以保留在 肺有同时进行的Anidulafungin治疗，为根除治疗的持续时间提供了理由 目标。他们还将确定免疫抑制的小鼠是否可以在撤离后传播感染 Anidulafungin，如果需要大量的ASCI。研究还将详细说明生命周期 气囊藻并提出新的目标策略。