BLR&D Research Career Scientist Award Application

BLR

• 批准号: 10451505
• 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: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10451505
• 关键词: 3-Dimensional; Age; American; Anidulafungin; Antifungal Agents; Area; Arthritis; Award; Biological; Biological Assay; Bone Marrow; Caring; Caspofungin; Cell Line; Cell Wall; Chemicals; Chloroquine; Chronic; Chronic Disease; Chronic Obstructive Pulmonary Disease; Clinical; Collaborations; Data; Development; Dihydrofolate Reductase Inhibitor; Disease; Dose; Drug Screening; Elderly; Evaluation; Female; Gene Expression; Gene Expression Profiling; General Population; Genes; Goals; HIV; HIV Seronegativity; HIV Seropositivity; Healthcare; Hematological Disease; Human; Immune; Immune system; Immunocompromised Host; Immunosuppression; Immunotherapy; In Vitro; Infection; Infection prevention; International; Interruption; Knowledge; Length; Life Cycle Stages; Lung; Malignant Neoplasms; Mammalian Cell; Methods; Micafungin; Microbiology; Microscopic; Midwestern United States; Mission; Modeling; Morbidity - disease rate; Mus; Mycoses; Ohio; Opportunistic Infections; Outcome; Partner in relationship; Patients; Pharmaceutical Preparations; Phase; Pneumocystis; Pneumocystis Infections; Pneumocystis carinii; Pneumocystis carinii Pneumonia; Pneumonia; Poland; Population; Portugal; Preclinical Drug Development; Proliferating; Property; Prophylactic treatment; Publications; Rattus; Reporting; Research; Rheumatoid Arthritis; Risk; Rodent Model; Role; Scientist; Seminal; Sexual Reproduction; Societies; Sphingolipids; Stress; Sulfamethoxazole; Therapeutic; Time; Toxic effect; Trimethoprim-sulfamethoxazole drug resistance; United States; Up-Regulation; Veterans; Withdrawal; analog; antimicrobial; asexual; base; cancer diagnosis; candidate identification; career; celecoxib; chronic inflammatory disease; clinically relevant; comorbidity; efficacy testing; experimental study; fungus; high risk; immunological status; immunosuppressed; infected vector rodent; knockout gene; male; metabolic abnormality assessment; military veteran; mortality; mouse model; new therapeutic target; novel therapeutics; pathogen; pathogenic fungus; polyglucosan; pre-clinical; prophylactic; response; screening; sex; targeted treatment; therapy duration; tool; transcriptome sequencing; transmission process; 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 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 posited that asci, and thus sexual replication, is required to facilitate progression through the life cycle leading to a productive infection. We further posited that presence of asci is required for transmission of Pneumocystis infection. In the present Merit Review, 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. These experiments will also identify whether immunosuppressed mice can transmit the infection after withdrawal of anidulafungin and if there is a critical number of asci needed. Finally, the studies will elaborate the life cycle of Pneumocystis and suggest new target strategies.

肺孢子虫。引起致命性肺炎(PCP)的专性真菌病原体是否受到免疫抑制 主持人。很少有药物能有效治疗PCP，而且几十年来一直没有新的治疗方法。 通常情况下，PCP与感染艾滋病毒的患者有关，然而，暴发性肺炎、PCP、 和感染人类的肺孢子虫的定植是#年出现的临床问题。 普通人群和退伍军人人群中的新易感人群，包括骨髓接受者； 接受免疫治疗的类风湿性关节炎和其他慢性炎症性疾病的患者；以及癌症 化疗和免疫疗法。肺孢子虫的生命周期被认为包含无性复制 周期和有性周期，包括交配，随后形成含有8个子囊孢子的子囊孢子(1)。在.期间 先前的优点综述表明，棘球菌素治疗感染P.Murina和P. 以β-1，3-D-葡聚糖(BG)合成为靶标的Carinii，耗尽了含有BG但大量 非BG表达的生命周期阶段留在肺内，不能增殖。我们进一步 证明了阿尼度芬净和卡泊芬净可以预防预防模型中的感染，提示 通过性周期形成ASCI可能是生产性感染所必需的(2)。基因分析 阿尼杜拉芬净处理小鼠后，小鼠肺泡巨噬细胞基因表达谱明显上调 与性复制有关，尽管由此产生的感染没有ASCI，这是性复制的产物 繁殖，这表明P.Murina试图进行有性复制，但由于缺乏 BG。根据这些数据，我们假设ASCI，从而性复制，是促进进展所必需的 通过生命周期导致生产性感染。我们进一步假设，ASCI的存在是 肺孢子虫感染的传播。在目前的功绩回顾中，我们将探索两个关键但未得到回答的问题 这些问题将导致对肺孢子虫生命周期的更深层次的了解，并暗示潜在的 靶向治疗的脆弱性伴随着阿尼度芬净治疗：(1)是否需要性复制 为了完成肺孢子虫的生命周期？过程中对P.Murina复制状态的跟踪 通过全球基因分析、血糖含量和显微镜方法，延长阿尼度芬净的治疗时间将揭示 非BG表达形式的数量是否保持：1)随着时间的推移保持不变，2)增加，或3)减少； 这表明：1)缺乏BG阻碍了复制；2)无性或替代复制阶段允许 真菌的存活；或3)缺乏有性复制导致感染的消除。(2)可以性行为 延长的阿尼杜拉芬净治疗停止后复制反弹？小鼠将被用来治疗 阿尼杜拉芬净疗程长达8周，有2个停药时间点。戒毒组中的小鼠将被跟踪 肺炎ASCI形成和复发的显微镜、血糖含量和基因表达证据 仍处于免疫抑制状态。治疗组和戒毒组的小鼠将被评估它们的能力 以传播感染和传播所需的ASCI临界数量。所有研究都将在 雄性和雌性小鼠，认为性是一个生物变量。棘球菌素在临床上可用于 美国。目前对PCP采用任何棘球菌素单一疗法都是不必要的，因为停药可能会导致 肺炎又回来了。拟议的研究结果将在以下方面具有直接的临床意义 同时给予阿尼杜拉芬太尼的肺孢子虫存活时间长短的测定 治疗，为以根除为目标的治疗持续时间提供了理由。这些实验还将 确定免疫抑制的小鼠在停药后是否会传播感染，以及 是所需的关键数量的ASCI。最后，这些研究将阐述肺孢子虫的生命周期，并建议 新的目标战略。