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.

肺孢子虫。是引起致命性肺炎(PCP)的专性真菌病原体 免疫功能受损的宿主。很少有药物对PCP有效，也没有新的治疗方法 几十年来的治疗。通常情况下，五氯酚与感染艾滋病毒的患者有关，然而，雷公藤 肺炎、卡式肺孢子虫和卡氏肺孢子虫(感染人类的物种)的定植正在出现 普通人群和包括骨骼在内的退伍军人中新易感人群的临床问题 接受骨髓移植；接受慢性免疫治疗的类风湿性关节炎和其他慢性疾病患者 炎症性疾病；癌症化疗和免疫疗法。提出了肺孢子虫的生活史 包含无性复制周期和有性周期，包括交配和随后形成的 ASCI含有8个子囊孢子(1)。在之前的功绩评估中，我们表明棘球菌素治疗 以β-1，3-D-葡聚糖合成(BG)为靶点的鼠类感染P.Murina和P.carinii，耗尽了Asci。 它们含有BG，但大量表达生命周期阶段的非BG仍留在肺中，并 不能扩散。我们进一步证明，阿尼度芬净和卡泊芬净可以预防感染 预防模式，这表明通过性周期形成ASCI可能是高效的 感染(2)。对阿尼杜拉芬净治疗的小鼠体内的P.Murina基因表达谱的分析显示， 与有性复制相关的基因上调，尽管由此产生的感染没有ASCI， 有性生殖的产物，表明P.Murina试图进行有性复制，但不能 由于缺乏BG。根据这些数据，我们假设ASCI，因此需要有性复制，以促进 在生命周期中的进展会导致生产性感染。我们进一步假设ASCI的存在是 是传播肺孢子虫感染所必需的。在目前的提案中，我们将探讨两个关键问题，但 未回答的问题将导致对肺孢子虫生命周期的更深层次的了解，并提出 在阿尼杜拉芬净治疗的同时，靶向治疗的潜在脆弱性： (1)肺孢子虫的生命周期是否需要有性复制？跟踪 用全局基因分析法研究阿尼杜拉芬净延长治疗过程中的复制状态 内容，以及微观方法将揭示非BG表达形式的数量是否保持：1)静态 随着时间的推移，2)增加，或3)减少；这表明：1)BG的缺乏阻碍了复制；2)无性或 可选择的复制阶段允许真菌存活；或3)缺乏有性复制导致消除 感染的可能性。 (2)阿尼杜拉芬净长期停药后，性复制能否反弹？老鼠会成为 阿尼度芬净治疗8周，停药2个时间点。戒毒组的小鼠将被 追踪ASCI形成和回归的显微镜、BG含量和基因表达证据 肺炎，同时仍处于免疫抑制状态。治疗组和戒毒组的小鼠将被 评估他们传播感染的能力和传播所需的ASCI临界数量。全 研究将在雄性和雌性小鼠身上进行，承认性别是一个生物学变量。 棘球菌素在美国临床上可以买到。目前使用任何棘球绦虫的单一疗法 因为PCP是不必要的，因为停药可能会导致肺炎复发。拟议研究的结果 将有直接的临床意义，通过确定存活的肺孢子虫可以在 同时使用anidulafungin治疗的肺部，为根除治疗的持续时间提供了理由 目标就是。他们还将确定免疫抑制小鼠在停药后是否可以传播感染 Anidulafungin，以及是否需要临界数量的ASCI。这些研究还将详细阐述 肺囊虫病，并提出新的目标策略。