冬虫夏草抗菌肽的序列测定及其生物学功能研究

The prevalence of antibiotic resistance is rising rapidly as a major threat to global health security. In addition, the growth of medical tourism has accelerated the generation and transmission of multi-drug resistant pathogenic isolates. Differ to antibiotics, antimicrobial peptides (AMPs) possess different mechanisms that eradicate bacteria instead of inhibit bacteria growth only. They are potent, broad spectrum and chemically diverse antimicrobial agents. They are not only able to wipe out drug resistance, but also prevent the generation of resistant strains. Therefore, they are emerging as novel therapeutic agents and substitutes of antibiotics. AMPs are part of the innate immune response and are found among all classes of life. They are therefore especially critical to insects and other non-gnathostomata organisms which do not have adaptive immune system. Ophiocordyceps Sinensis is a entomopathogenic fungus that parasitizes ghost moths larvae and produces a fruiting body to form a entomo-fungal complex which is recognized as a Traditional Tibetan Medicine Yartsa Gunbu (Dong Chong Xia Cao) and reputed for its immunoregulatory and anti-infectious function. Theoretically, as key molecules of the insect innate immune response to infection, AMPs should be produced in large quantities by ghost moths and may remained in the corpse and exerted their pharmacological effects in the complex. However, whether the antimicrobial peptide is one of the mechanisms of its antimicrobial activity is remains unkown. In this subject, AMPs are isolated through chromatography, sequenced using Next-generation transcriptome sequencing and de novo peptide sequencing technologies, synthesized by solid-phase peptide synthesis; their physical chemical properties and biological activitities are analyzed by a series of in vitro and in vivo experiments. This research will present a fresh perspective on understanding the pharmaceutical activities of Yartsa Gunbu and provide a new approach to developing novel anti-infective drugs from Traditional Tibetan Medicine.

抗生素耐药性问题正在不断加剧成为一项全球性卫生威胁。而医疗旅行的增长更是加速了对多种抗生素具有耐药性的病原体在国际间传播。抗菌肽是广谱抗菌的活性肽类物质，因不同于抗生素的作用机制，能在避免耐药性的出现的同时杀灭已经产生耐药性的病原体。同时因其抗菌谱广、能力强、种类多等特点，有望成为新一代临床抗菌药物。抗菌肽作为先天免疫反应进化过程中的相对保守成分，普遍存在于各种生物体中。抗菌肽对于生物体，尤其是昆虫等不具备后天免疫系统的非有颔下门动物起着至关重要的作用。冬虫夏草由真菌寄生于蝠蛾幼虫演化而成，是具有抗感染及调节免疫等多重功效的传统名贵药材。根据其成因分析，抗菌肽有可能由蝠蛾幼虫产生，并留存于冬虫夏草内而成为其活性成分之一。本课题拟通过色谱法分离其抗菌肽组分，并通过转录组测序与多肽测序相结合的办法确定其蛋白序列，随后通过固相多肽合成获得多肽纯品，进而对其理化性质及生物学功能进行深入研究。

抗生素耐药性问题正在不断加剧成为一项全球性卫生威胁。而医疗旅行的增长更是加速了对多种抗生素具有耐药性的病原体在国际间传播。抗菌肽是广谱抗菌的活性肽类物质，因不同于抗生素的作用机制，能在避免耐药性的出现的同时杀灭已经产生耐药性的病原体。同时因其抗菌谱广、能力强、种类多等特点，有望成为新一代临床抗菌药物。抗菌肽作为先天免疫反应进化过程中的相对保守成分，普遍存在于各种生物体中。抗菌肽对于生物体，尤其是昆虫等不具备后天免疫系统的非有颔下门动物起着至关重要的作用。冬虫夏草由真菌寄生于蝠蛾幼虫演化而成，是具有抗感染及调节免疫等多重功效的传统名贵药材。根据其成因分析，抗菌肽有可能由蝠蛾幼虫产生，并留存于冬虫夏草内而成为其活性成分之一。本课题拟通过色谱法分离其抗菌肽组分，并通过转录组测序与多肽测序相结合的办法确定其蛋白序列，随后通过固相多肽合成获得多肽纯品，进而对其理化性质及生物学功能进行深入研究。结果表明，冬虫夏草抗菌肽在体外和体内均表现出强大的抗菌活性，且不引起溶血效应，因此具有较好的成药潜力。电镜结果显示，抗菌肽能够诱导微生物细胞膜发生明显的形态学和生物物理变化，表明抗菌作用与破坏细胞膜的机制有关。总之，本研究不仅为冬虫夏草抗菌肽的研究提供了帮助，还为高通量天然抗菌肽的发现提供了实用的策略。本项目的开展及其成果，有望对该领域的未来研究产生重要影响。