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.

肺孢子虫属是专性真菌病原体，在免疫功能低下的患者中引起致命性肺炎（PCP） hosts.很少有药物对PCP有效，几十年来没有新的治疗方法。 通常，PCP与感染HIV的患者有关，然而，暴发性肺炎，PCP， 和肺孢子虫jirovecii（感染人类的物种）的定植是新出现的临床问题， 普通人群和退伍军人人群中的新易感人群，包括骨髓受体; 接受类风湿性关节炎和其他慢性炎性疾病免疫治疗的患者;以及癌症 化疗和免疫疗法。肺孢子虫的生活史包括无性繁殖和无性繁殖 一个周期和一个有性周期，包括交配和随后形成的含有8个子囊孢子的子囊（1）。期间 在以前的Merit综述中，我们表明棘白菌素治疗鼠疟原虫和鼠疟原虫感染的啮齿动物。 靶向β-1，3-D-葡聚糖合成（BG）的卡氏藻耗尽了含有BG但大量 不表达BG的生命周期阶段保留在肺中并且不能增殖。我们进一步 表明阿尼芬净和卡泊芬净在预防性模型中可以预防感染，表明 通过性周期形成ASCI可能是生产性感染所必需的（2）。分析基因 在用阿尼芬净处理的小鼠中，鼠疟原虫的表达谱显示基因的强烈上调 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，表明P. murina试图进行有性复制，但由于缺乏 BG。基于这些数据，我们假设ASCI，以及性复制，是促进进展所必需的 在整个生命周期中导致生产性感染。我们进一步假设，ASCI的存在是 肺孢子虫感染的传播。在本Merit Review中，我们将探讨2个关键但未回答的问题 这些问题将导致更深入地了解肺孢子虫的生命周期，并提出潜在的 阿尼芬净治疗伴随的靶向治疗的弱点：（1）是否需要性复制 完成肺孢子虫的生命周期鼠肺吸虫感染过程中复制状态的跟踪 通过整体基因分析、BG含量和显微镜方法， 非BG表达形式数量是否保持：1）随时间静止，2）增加，或3）减少; 提示：1）缺乏BG阻止复制; 2）无性或替代复制阶段允许 真菌的存活;或3）缺乏性复制导致感染的消除。(2)可以性 阿尼芬净长期治疗停止后复制反弹？小鼠将接受以下处理： 阿尼芬净治疗长达8周，有2个停药时间点。将跟踪停止组中的小鼠， 显微镜下，BG含量和基因表达证据表明腹水形成和肺炎复发， 仍处于免疫抑制状态将评价给药组和停药组小鼠的能力 以及传播所需的ASCI临界数量。所有研究将在 雄性和雌性小鼠，将性别视为生物学变量。棘白菌素在临床上可用于 美国的目前使用棘白菌素治疗PCP的单一疗法是不必要的，因为停药可能导致 肺炎复发。拟议研究的结果将具有直接的临床意义， 测定与阿尼芬净同时使用时活肺孢子虫在肺中的存留时间 治疗，提供以根除为目标的治疗持续时间的依据。这些实验也将 确定免疫抑制小鼠在阿尼芬净停药后是否可以传播感染， 是所需ASCI的临界数量。最后，研究将阐述肺孢子虫的生命周期，并建议 新的目标战略。