The role of sex in the life cycle and transmission of Pneumocystis

性在肺孢子虫生命周期和传播中的作用

• 批准号: 10350565
• 负责人: Melanie T Cushion
• 金额: $ 48.82万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10350565
• 关键词: 3-Dimensional; Address; Anidulafungin; Antifungal Agents; Biological Assay; Biological Markers; Cell Cycle; Chronic; Clinical; Competence; Complex; Data; Diagnosis; Dose; Electron Microscopy; Electrons; Evaluation; Exposure to; Gene Expression; Genes; HIV; Immunocompromised Host; Immunotherapy; Infection; Interruption; Lead; Life Cycle Stages; Lung; Malignant Neoplasms; Mass Spectrum Analysis; Measurement; Methods; Microbe; Microscopic; Modeling; Morphology; Mus; Organism; Outcome; Partner in relationship; Patients; Pharmaceutical Preparations; Phase; Pneumocystis; Pneumocystis carinii; Pneumonia; Population; Proliferating; Prophylactic treatment; Proteins; Proteomics; Reporting; Rheumatoid Arthritis; Role; Series; Sexual Transmission; Signal Transduction; Techniques; Time; Withdrawal; asexual; base; fungus; genetic signature; mouse model; novel; novel therapeutics; pathogenic fungus; pneumonia treatment; polyglucosan; potential biomarker; prevent; prophylactic; sex; sexual role; targeted agent; therapeutic target; tool; transmission process; treatment duration

Pneumocystis spp. are host 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. PCP remains a problem in HIV-infected patients and is emerging as a clinical concern in newly susceptible populations including patients receiving immunotherapy for chronic conditions. We recently reported that treatment of PCP in murine models with the echinocandins, anti-fungal agents that target β-1,3-D-glucan synthesis (BG), depleted the asci which contain BG, but large numbers of forms that do not express BG remained in the infected lungs and were apparently unable to proliferate. Notably, the treated mice could not transmit the infection without asci. The echinocandins prevented PCP when administered prophylactically at higher doses, suggesting that formation of asci via the sexual cycle may be required for a productive infection. Genes associated with sexual replication and cell cycle perturbation comprised the strongest up-regulated signals in P. murina from anidulafungin treated mice. These infections were devoid of asci, 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 for progression through the Pneumocystis life cycle. The importance of the sexual cycle for survival of Pneumocystis will be investigated using the anidulafungin treatment and prophylactic models. The specific aims address 2 major questions we propose to pursue: Question 1: Is sexual replication required for completion of the life cycle of Pneumocystis? 3 aims will be used to address this question. The first will be to assess the replication competency of P. murina treated with anidulafungin by transferring them to new hosts. Replication will be determined by a combination of microscopic methods, BG measurement, and quantitative PCR. The second aim will use the prophylactic model to allow low level replication to ask whether replication occurs via the sexual cycle, using the same methods. The third aim will determine whether P. murina can survive during prolonged anidulafungin treatment in the same hosts without proceeding through the sexual cycle or if it is eventually cleared. Question 2: At what point in the Pneumocystis life cycle can the infection be transmitted? The sexual cycle returns after withdrawal of anidulafungin. During 10 days to 4 weeks post-cessation, we will track the emergence of the sexual cycle and identify gene signatures, biomarkers and numbers of asci prior to exposing these mice to naïve recipients. Using these data, we will determine at what point in the life cycle transmission takes place and the thresholds necessary for transmission. Selected proteins based on gene expression data will be validated by proteomics as potential biomarkers associated with return of the sexual cycle and transmission. These studies will identify potential vulnerabilities in the Pneumocystis life cycle that could be exploited for interdiction and add to our understanding of its life cycle and transmission.

肺孢子菌是导致致命性肺炎 (PCP) 的宿主专性真菌病原体。 很少有药物对免疫功能低下的宿主有效，并且目前还没有针对其的新疗法。 几十年来，PCP 的治疗仍然是 HIV 感染患者的一个问题，并且正在成为一个临床问题。 新的易感人群，包括接受慢性病免疫治疗的患者。 我们最近报道了用棘白菌素（一种抗真菌药物）治疗小鼠模型中的 PCP 目标 β-1,3-D-葡聚糖合成 (BG)，耗尽了含有 BG 的子囊，但大量形式确实如此 不表达的 BG 仍保留在受感染的肺部，并且显然无法增殖。 小鼠在没有腹腔注射的情况下无法传播感染，注射棘白菌素可以预防 PCP。 以较高剂量进行预防，表明通过性周期形成子囊可能是 与有性复制和细胞周期扰动相关的基因包括 来自阿尼芬净治疗的小鼠的 P. murina 中的上调信号最强，这些感染没有。 asci，表明 P. murina 试图进行有性复制，但由于缺乏 BG 而无法进行。 基于这些数据，我们认为 asci 以及性复制是通过 肺孢子虫的生命周期。性周期对于肺孢子虫的生存的重要性。 使用阿尼芬净治疗和预防模型进行研究，具体目标涉及两个主要目标。 我们建议探讨的问题： 问题 1：完成生命周期是否需要有性复制 肺孢子菌？ 3 个目标将用于解决这个问题。第一个目标是评估复制性。 通过将它们转移到新宿主，用阿尼芬净处理的 P. murina 的能力将被复制。 通过结合显微镜方法、BG 测量和定量 PCR 来确定。 目标将使用预防模型来允许低水平复制，以询问复制是否通过性传播发生 第三个目标将确定 P. murina 能否在较长时间内生存。 在同一宿主中进行阿尼芬净治疗，但未经历性周期或最终发生性周期 问题 2：肺孢子虫生命周期的哪个阶段可以传播感染？ 停药后 10 天至 4 周内，我们将跟踪性周期恢复情况。 性周期的出现并在发生之前识别基因特征、生物标志物和 asci 数量 使用这些数据，我们将确定这些小鼠处于生命周期的哪个阶段。 发生传播以及基于基因选择的蛋白质的阈值。 表达数据将通过蛋白质组学验证为与性回归相关的潜在生物标志物 这些研究将确定肺孢子虫生命周期中潜在的脆弱性。 可以用来拦截并增加我们对其生命周期和传播的理解。