Effect of Microenvironment on the Activity of Mycobacteriophages for Treating Mycobacterium abscessus

需要新的治疗方法来控制日益严重的抗药性细菌感染问题。 噬菌体是感染和杀死细菌的病毒。因为噬菌体和抗生素在它们的 杀伤机制，噬菌体疗法是预防和治疗耐药的潜在策略 细菌。 耐药的非结核分枝杆菌(NTM)感染正在上升，它们是一个重大威胁 适用于患有囊性纤维化(CF)、慢性阻塞性肺疾病等潜在肺部疾病的人 慢性阻塞性肺疾病(COPD)或非慢性阻塞性肺疾病。脓肿分枝杆菌是最常见的非霍奇金淋巴瘤之一。 在肺部NTM疾病中也是最难治疗的。脓肿分枝杆菌极具抗药性， 目前还没有系统证明有效的养生法。噬菌体疗法，涉及三人鸡尾酒 分枝杆菌噬菌体(霉菌噬菌体)，最近被用于在同情的使用条件下治疗 1例CF患者的播散性脓肿分支杆菌病。这种真菌噬菌体治疗与临床有关。 病人的病情好转了。然而，患者的脓肿分枝杆菌感染尚未完全治愈， 两年后，每天两次的静脉分枝杆菌治疗正在进行中。正在进行的 真菌噬菌体的治疗方法尚不清楚。 噬菌体疗法的一个重大知识空白是噬菌体是否能与宿主细菌相互作用 在感染过程中遇到不同的微环境。脓肿分枝杆菌能够在细胞内存活 巨噬细胞和细胞外的生物膜。真菌噬菌体能否在这些细菌中杀死脓肿分支杆菌 环境是未知的。霉菌噬菌体在正常粘液或病理性CF中的穿透和作用能力 粘液也是未知的。使用脓肿分枝杆菌分离株和真菌噬菌体的集合，包括 从正在进行的临床病例中，我们将评估每个潜在屏障(巨噬细胞、 生物膜和粘液)对真菌噬菌体活性的影响。这些研究的结果将有助于揭示微环境 这可能会限制脓肿分枝杆菌的噬菌体活动，更广泛地说，可能会向 噬菌体治疗细胞内、生物被膜形成和肺部细菌病原体。我们希望了解到 Gain将推动战略的发展，以改进噬菌体疗法作为预防和治疗药物的选择 具有抗药性的细菌感染。鉴于治疗分枝杆菌脓肿的需要，这款R21对 NOT-AI-17-016(NIAID对非艾滋病相关、肺部非艾滋病的生物医学研究感兴趣的通知 结核分支杆菌(NTM)感染)。

Novel therapies are needed to control the growing problem of antibiotic-resistant bacterial infections. Bacteriophages (phages) are viruses that infect and kill bacteria. Because phages and antibiotics differ in their killing mechanisms, phage therapy is a potential strategy for prevention and treatment of drug resistant bacteria. Drug resistant nontuberculous mycobacteria (NTM) infections are on the rise and they are a significant threat for people with underlying lung diseases such as cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD) or non-CF bronchiectasis. Mycobacterium abscessus is one of the most common NTMs encountered in pulmonary NTM disease and it is the most difficult to treat. M. abscessus is extremely drug resistant and there is no systematically proven regimen that is effective. Phage therapy, involving a cocktail of three mycobacteriophages (mycophages), was recently employed under compassionate use conditions to treat disseminated M. abscessus disease in a CF patient. This mycophage treatment was associated with clinical improvement of the patient. However, the M. abscessus infection of the patient has yet to fully resolve and twice-daily treatment with intravenous mycophages is ongoing two years later. The limitations of the ongoing mycophage treatment are unknown. A significant gap in knowledge for phage therapy is whether phages can interact with their host bacteria in the different microenvironments encountered during infection. M. abscessus is able to both survive intracellularly in macrophages and extracellularly in biofilms. Whether mycophages can kill M. abscessus in these environments is unknown. The ability of mycophages to traverse and act in normal mucus or pathological CF mucus is also unknown. Working with a collection of M. abscessus isolates and mycophages, including those from the ongoing clinical case, we will evaluate the impact of each of these potential barriers (macrophages, biofilms, and mucus) on mycophage activity. The results of these studies will shed light on microenvironments that may limit phage activity for M. abscessus specifically and, more broadly, inform on potential challenges to phage therapy for intracellular, biofilm forming, and pulmonary bacterial pathogens. We expect the knowledge gained will drive development of strategies to improve phage therapy as an option to prevent and treat drug resistant bacterial infections. Given the need for therapies to treat M. abscessus, this R21 is responsive to NOT-AI-17-016 (Notice of NIAID’s Interest in Biomedical Research in non-AIDS associated, Pulmonary Non- Tuberculous Mycobacterial (NTM) Infections).