Targeted pan-antibacterial liposomes to control pathogenic mycobacteria

DectiSomes是携带抗感染药物并涂覆有病原体受体的脂质纳米颗粒， 靶向致病细胞。DectiSomes可降低抑制和杀灭病原体的有效剂量 相对于常规药物的数量级，可能克服多药治疗的障碍， 抗性和持久性细胞。在此，我们提出了泛抗菌DectiSomes的初步发展， 测试它们对三种致病分枝杆菌的抵抗力。世界上四分之一的人口有潜在的 或由结核分枝杆菌引起的活动性结核感染。有数百万新的结核病病例， 1.7每年有百万人死亡。M. avium和M.溃疡会导致危及生命的肺部和危险的皮肤 感染，并且是结核病的极好实验室模型。致病性分枝杆菌和真菌 病原体具有细胞壁和大量富含寡聚糖和寡脂聚糖的胞外多糖基质。 C型凝集素病原体受体Dectin-1（DEC 1）、Dectin-2（DEC 2）和DC-SIGN（DCS 12）识别 这些寡聚糖的不同交联变体并向免疫系统发出病原体感染的信号。在 先前的出版物表明，用DEC 1、DEC 2和DEC 3包被的负载抗真菌药物的DectiSomes 在小鼠疾病模型中，DCS 12在体外和体内均有效靶向并杀死多种真菌病原体。 我们对这一建议的工作假设是，抗菌药物载脂质体靶向致病性 通过病原体受体的细菌将比非靶向抗菌药物有效得多。我们强大 支持这一假设的初步数据表明，用Dectin- 1、Dectin-2和DCS 12与M.鸟类细胞及其胞外多糖基质的数量级更多 强于非靶向脂质体或蛋白质包被的对照脂质体。为了进一步探索这一假设，我们 我们将追求以下具体目标。1.确定受体靶向利福平的效率和动力学 RIF负载的脂质体DEC 1-RIF-LL、DEC 2-RIF-LL和DCS 12-RIF-LL与M的结合。tuberculosis，M. avium和M.在体外不同条件下生长的溃疡。2.确定RIF的有效剂量（艾德） 通过DEC 1-RIF-LL和DEC 2-RIF-LL递送的对体外生长的M. tuberculosis，M. avium和M.溃疡并显示出改善的药物功效。3.使用小鼠模型， TB（即，感染M.肺结核），证明通过口服递送的DEC 1-RIF-LL和DEC 2-RIF-LL 吸入和/或静脉注射显著降低了真菌负荷减少95%的有效剂量 相对于非靶向RIF-LLs和游离RIF，RIF-LLs具有更高的ED 95，并改善肺病理生理学。 预期的结果是一种精确的靶向抗菌药物输送系统， 控制致病性分枝杆菌感染的有效剂量和治疗次数， 药物对患者的毒性。我们相信，一旦开发出DectiSome相关技术， 这是一个巨大的飞跃，需要克服当前抗菌药物开发的严重限制。

DectiSomes are lipid nanoparticles carrying an anti-infective drug and coated with pathogen receptor that targets them to pathogenic cells. DectiSomes reduce the effective dose for inhibition and killing of pathogens by order(s) of magnitude relative to conventional drugs, potentially overcoming the barriers of multidrug resistant and persister cells. Herein we propose the initial development of pan-antibacterial DectiSomes, testing them against three pathogenic mycobacterial species. One quarter of the world’s population have latent or active TB infections caused by Mycobacterium tuberculosis. There are several million new cases of TB and 1.7 million deaths every year. M. avium and M. ulcerans cause life-threatening pulmonary and dangerous skin infections, respectively and are excellent laboratory models of TB. Pathogenic mycobacteria and fungal pathogens have cell walls and extensive exopolysaccharide matrices rich in oligoglycans and oligolipoglycans. The C-type lectin pathogen receptors Dectin-1 (DEC1), Dectin-2 (DEC2) and DC-SIGN (DCS12) recognize diverse crosslink variants of these oligoglycans and signal the immune system of a pathogen infection. In previously publications we’ve shown that antifungal drug loaded DectiSomes coated with DEC1, DEC2 and DCS12 effectively target and kill diverse fungal pathogens both in vitro and in vivo in mouse disease models. Our working hypothesis for this proposal is that antibacterial drug loaded liposomes targeted to pathogenic bacterial by pathogen receptors will be far more efficacious than untargeted antibacterial drugs. Our strong preliminary data supporting this hypothesis show that rhodamine red fluorescent liposomes coated with Dectin- 1, Dectin-2 and DCS12 bound to M. avium cells and their exopolysaccharide matrix orders of magnitude more strongly than untargeted liposomes or protein coated control liposomes. To further explore this hypothesis, we will pursue the following Specific Aims. 1. Determine the efficiency and kinetics of receptor targeted rifampin RIF-Loaded Liposomes DEC1-RIF-LLs, DEC2-RIF-LLs and DCS12-RIF-LLs binding to M. tuberculosis, M. avium and M. ulcerans grown under various conditions in vitro. 2. Determine the effective dose (ED) of RIF delivered by DEC1-RIF-LLs and DEC2-RIF-LLs for 95% inhibition and/or killing (ED95) of in vitro grown M. tuberculosis, M. avium and M. ulcerans and demonstrate improved drug efficacy. 3. Using a mouse model of TB (i.e., infected with M. tuberculosis), demonstrate that DEC1-RIF-LLs and DEC2-RIF-LLs delivered by oral aspiration and/or intravenous injection dramatically lower the effective dose for 95% reduction in fungal burden (ED95) and improve lung pathophysiology, relative to untargeted RIF-LLs and free RIF. The expected outcome is a precision targeted antibacterial system of drug delivery that reduces the effective dose and number of treatments to control pathogenic mycobacterial infections and hence may reduce drug toxicity to patients. We believe that once developed DectiSome-related technologies will provide the dramatic leap forward needed to overcome the serious current limitations to antibacterial drug development.