昆虫抗菌肽基因工程及其分子设计研究进展(英文)

昆虫抗菌肽是昆虫免疫后存在于血淋巴中的一类活性肽,具有广谱抗菌的生物活性,因而昆虫抗菌肽基因工程迅速成为生命科学领域的研究热点之一.介绍了昆虫抗菌肽的基因结构和表达,综述了昆虫抗菌肽的人工合成与改造以及转基因工程的研究成果,概述了昆虫抗菌肽的分子设计方法和现状,并展望了昆虫抗菌肽的应用前景.     

昆虫抗菌肽的研究进展

昆虫的种类繁多,约几百万种,为适应各种不同的生态环境,建立了自己独特的免疫系统,抗菌肽就是免疫体系中的关键成分,过去,抗菌肽的主要研究方面是昆虫免疫和昆虫生化,目前不少工作从分子水平上进行探讨。     

昆虫天然免疫反应分子机制研究进展

昆虫体内缺乏高等脊椎动物所具有的获得性免疫系统, 只能依赖发达的天然免疫系统抵抗细菌、 真菌、 病毒等外源病原物的侵染。本文概括了昆虫天然免疫反应发生和作用的分子机制相关进展, 重点阐述了重要免疫相关因子在昆虫天然免疫反应中的功能和作用机制。昆虫天然免疫反应分为体液免疫和细胞免疫两种, 二者共同作用完成对病原物的吞噬 (phagocytosis)、 集结 (nodulation)、 包囊 (encapsulation)、 凝结 (coagulation)和黑化（melanization）等。当昆虫受到外界病原物的侵染时, 首先通过体内的模式识别蛋白（pattern recognition proteins/receptor, PRPs）识别并结合病原物表面特有的模式分子（pathogen-associated molecular pattern, PAMPs）, 继而一系列包括丝氨酸蛋白酶和丝氨酸蛋白酶抑制剂在内的级联激活反应被激活和调控, 产生抗菌肽、 黑色素等免疫效应分子, 清除或杀灭外源物。抗菌肽是一类小分子量的阳离子肽, 具有广谱抗菌活性, 针对不同类型的病原物, 抗菌肽的产生机制也不尽相同。昆虫体内存在着两种信号转导途径调节抗菌肽的产生： 一是由真菌和大部分革兰氏阳性菌激活的Toll途径; 二是由革兰氏阴性菌激活的Imd途径（immune deficiency pathway）。这两个途径通过激活不同转录因子调控不同抗菌肽基因的表达参与昆虫体内的天然免疫反应。     

昆虫抗菌肽的生理活性及其转基因应用前景

昆虫抗菌肽是昆虫免疫后存在于血淋巴中的一类活性肽。根据分子的结构可分为 5类 :天蚕素类、昆虫防御素、富含脯氨酸或精氨酸的抗菌肽、富含甘氨酸的抗菌肽、抗真菌肽。且具有广谱的抗菌、抗病毒、抑制肿瘤的生物活性。概述了昆虫抗菌肽的基因的克隆与表达及转基因研究方面的进展 ,并展望了抗菌肽在基因工程中的应用前景     

PI3K和受体型酪氨酸激酶介导家蚕麻痹肽免疫诱导信号的传递

【目的】普遍存在于鳞翅目昆虫中的ENF肽具有非常相似的结构和生理功能, 对昆虫的发育、 免疫、 应激反应等方面都起着重要的调控作用。有研究报道, 作为ENF肽家族成员之一的家蚕Bombyx mori麻痹肽（paralytic peptide, PP）通过激活MAPK来调控家蚕的免疫应答, 但其完整的分子作用机制尚不明确。本研究旨在解析传递家蚕PP免疫诱导信号的分子通路。【方法】首先通过荧光定量PCR检测了多种昆虫细胞系在PP诱导下抗菌肽基因的转录水平, 并利用Western blot检测p38 MAPK的磷酸化水平, 然后利用不同信号传递分子的抑制剂处理BmE细胞筛选参与传递PP免疫诱导信号的分子。【结果】PI3K抑制剂LY294002和受体型酪酸激酶抑制剂Genistein抑制了PP对BmE细胞抗菌肽基因表达的诱导作用; 且BmE细胞和家蚕血细胞在PP的诱导下, Akt和大小约为70 kDa的细胞膜蛋白均出现磷酸化水平的动态变化。【结论】PI3K/Akt信号通路和Genistein敏感性的受体型酪氨酸激酶介导了PP免疫诱导信号的传递。     

昆虫抗茵肽的生理活性及其转基因应用前景

昆虫抗菌肽是昆虫免疫后存在于血淋巴中的一类活性肽.根据分子的结构可分为5类天蚕素类、昆虫防御素、富含脯氨酸或精氨酸的抗菌肽、富含甘氨酸的抗菌肽、抗真菌肽.且具有广谱的抗菌、抗病毒、抑制肿瘤的生物活性.概述了昆虫抗菌肽的基因的克隆与表达及转基因研究方面的进展,并展望了抗菌肽在基因工程中的应用前景.     

昆虫天然免疫反应研究前沿

昆虫天然免疫反应分为体液免疫和细胞免疫两种,二者共同作用抵御细菌、真菌、病毒等外源病原物的侵染。体液免疫反应主要包括黑色素形成和抗菌肽产生两种机制,细胞免疫反应包括吞噬、集结和包囊等作用类型。在昆虫天然免疫反应中,昆虫模式识别蛋白负责识别并结合外源物表面特有的模式分子,丝氨酸蛋白酶、丝氨酸蛋白酶抑制剂、各种配体、受体等负责级联信号途径的激活和调控,抗菌肽、黑色素等效应分子则负责对入侵物的杀灭和清除。本文根据国外和作者自己的研究,综述了昆虫天然免疫反应的研究进展,并针对该领域最新的研究动态展望了昆虫肠道免疫、昆虫免疫致敏以及不完全变态昆虫免疫学等这些研究前沿。     

昆虫抗菌肽的结构和功能研究现状

昆虫抗菌肽是昆虫血淋巴中的一类活性肽。在昆虫感染病菌或体壁受到损伤的情况下其脂肪体能迅速合成一系列抗菌活性物质并释放到血淋巴中发挥作用,抑杀多种致病菌、真菌、病毒等,但不破坏生物体的正常细胞。对昆虫抗菌肽的结构特征、生物活性及抗菌肽分子的作用模式的最新研究进展作了综述。     

昆虫抗菌肽的研究进展

昆虫抗菌肽是昆虫先天免疫中起重要的作用的一类免疫效应因子,具有广谱抗菌、抗病毒、抑制肿瘤的生物活性和很好应用前景.本文主要介绍昆虫抗菌肽的类型、抗菌机理和分子设计的研究进展.     

昆虫抗菌肽研究和应用现状

昆虫在受到刺激或感染之后,在其血淋巴中会产生一种抗菌类物质,称抗菌肽。抗菌肽具有分子小、稳定性好、广谱抗菌、无毒副作用等特点,在农业、医药、食品等领域有广泛的应用前景。简要综述了昆虫抗菌肽的基础研究和应用现状。     

Insect antimicrobial peptides and their applications

Insects are one of the major sources of antimicrobial peptides/proteins (AMPs). Since observation of antimicrobial activity in the hemolymph of pupae from the giant silk moths Samia Cynthia and Hyalophora cecropia in 1974 and purification of first insect AMP (cecropin) from H. cecropia pupae in 1980, over 150 insect AMPs have been purified or identified. Most insect AMPs are small and cationic, and they show activities against bacteria and/or fungi, as well as some parasites and viruses. Insect AMPs can be classified into four families based on their structures or unique sequences: the α-helical peptides (cecropin and moricin), cysteine-rich peptides (insect defensin and drosomycin), proline-rich peptides (apidaecin, drosocin, and lebocin), and glycine-rich peptides/proteins (attacin and gloverin). Among insect AMPs, defensins, cecropins, proline-rich peptides, and attacins are common, while gloverins and moricins have been identified only in Lepidoptera. Most active AMPs are small peptides of 20–50 residues, which are generated from larger inactive precursor proteins or pro-proteins, but gloverins (~14 kDa) and attacins (~20 kDa) are large antimicrobial proteins. In this mini-review, we will discuss current knowledge and recent progress in several classes of insect AMPs, including insect defensins, cecropins, attacins, lebocins and other proline-rich peptides, gloverins, and moricins, with a focus on structural-functional relationships and their potential applications.     

昆虫天然免疫相关基因研究进展

在长期进化过程中,昆虫形成了强大的天然免疫防御系统,即体液免疫和细胞免疫。体液免疫主要包括Toll、IMD和JAK/STAT 3条信号通路,通过信号转导及免疫途径调控免疫相关基因的表达,诱导产生抗菌肽和其他效应分子。细胞免疫由血细胞介导,主要完成对病原物的包裹、吞噬和集结等。近年来,昆虫基因组学快速发展,通过生物信息学等方法从昆虫基因组数据中已鉴定到大量免疫相关基因,对这些基因的研究加深了人们对昆虫天然免疫分子机制的认识和理解。根据基因功能,免疫相关基因分为识别、信号转导、调制器、效应分子、黑化反应、RNA干扰和其他基因等7类,这些基因通过互作来调控体液免疫和细胞免疫。本文对昆虫免疫相关基因的分类、功能及家族进化等方面的研究成果进行总结,并对今后昆虫免疫的研究重点进行了展望,以期为昆虫免疫分子机制的研究及开发新的害虫防治策略提供依据。     

BmMD-2A responds to 20-hydroxyecdysone and regulates Bombyx mori silkworm innate immunity in larva-to-pupa metamorphosis

20E-hydroxyecdysone (20E) plays important roles in larval molting and metamorphosis in insects and is also involved in the insect innate immune response. Insect metamorphosis is a highly successful strategy for environmental adaptation and is the most vulnerable stage during which the insect is susceptible to various pathogens. 20E regulates a series of antimicrobial peptides (AMPs) through the immunodeficiency (IMD) pathway activation in Drosophila; nevertheless, whether other immune pathways are involved in 20E-regulated insect immunity is unknown. Our previous studies showed that BmMD-2A is a member of the MD-2-related lipid recognition (ML) family of proteins that are involved in the Bombyx mori innate immunity Toll signaling pathway. In this study, we further demonstrate that BmMD-2A is also positively regulated by 20E, and the BmMD-2A neutralization experiment suggested that 20E activates some downstream immune effect factors, the AMP genes against Escherichia coli and Staphylococcus aureus, through the regulation of BmMD-2A in larval metamorphosis, implying that B. mori may use the Toll-ML signaling pathway to maintain innate immune balance in the larval-pupal metamorphosis stage, which is a different innate immunity pathway regulated by 20E compared to the IMD pathway in Drosophila.     

Insect antimicrobial peptides: structures, properties and gene regulation

Antimicrobial peptides (AMPs) are part of the armament that insects have developed to fight off pathogens. Insect AMPs are typically cationic and often made of less than 100 amino acid residues. Although their structures are diverse, most of the AMPs can be assigned to a limited number of families. The most common structures are represented by peptides assuming a alpha-helical conformation in organic solutions or disulfide-stabilized beta-sheets with or without alpha-helical domains present. The diverse activity spectrum of these peptides may indicate different modes of action. Genetic analysis in the Drosophila model evidenced that multiple signal transduction pathways are activating the genes coding AMPs.     

黄粉虫抗茵肽TmAMP3在大肠杆菌中的高效表达及活性检测

昆虫抗菌肽具有广谱抗菌活性,克隆黄粉虫Tenebrio molitor抗菌肽基因,进行原核表达和活性检测,为昆虫抗菌肽推广应用奠定一定基础.根据GenBank公布的黄粉虫抗菌肽序列设计特异引物,以RT-PCR法从黄粉虫体内克隆了抗菌肽基因TmAMP3,将其亚克隆至pET-30a表达载体中,转化到大肠杆菌Escheric...     

Antimicrobial peptides isolated from insects and their potential applications

Antimicrobial peptides (AMPs) in insects have the potential to be developed as chemotherapy agents against numerous microbial species. This article reviewed the existing knowledge of what have been focused so far on published materials related to AMPs isolated from insects. Previous studies were focused on peptide characterization and the mechanism pathways of different AMPs from a variety of insect Orders. Most studied insect Orders are as follows: Hymenoptera (50%), Diptera (17%), Coleoptera (13%), Lepidoptera (10%), Hemiptera (5%), Blattodea (3%) and Odonata (2%). Dozens of new AMPs have been extracted from insects recently. However, more studies in vivo and in vitro are necessary to fully understand their effect and the mechanisms of antimicrobial action to utilize their promising potential in cosmetic and pharmaceutical industries.     

Studies on the antileishmanial properties of the antimicrobial peptides temporin A,B and 1Sa

Given the paucity and toxicity of available drugs for leishmaniasis, coupled with the advent of drug resistance, the discovery of new therapies for this neglected tropical disease is recognised as being of the utmost urgency. As such antimicrobial peptides (AMPs) have been proposed as promising compounds against the causative Leishmania species, insect vector‐borne protozoan parasites. Here the AMP temporins A, B and 1Sa have been synthesised and screened for activity against Leishmania mexicana insect stage promastigotes and mammalian stage amastigotes, a significant cause of human cutaneous disease. In contrast to previous studies with other species the activity of these AMPs against L. mexicana amastigotes was low. This suggests that amastigotes from different Leishmania species display varying susceptibility to peptides from the temporin family, perhaps indicating differences in their surface structure, the proposed target of these AMPs. In contrast, insect stage L. mexicana promastigotes were sensitive to two of the screened temporins which clearly demonstrates the importance of screening AMPs against both forms of the parasite. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.     

昆虫抗菌肽的生物学特点及药物研发进展

昆虫抗菌肽是由昆虫细胞特定基因编码、由细胞核糖体合成的,具有体液免疫功能的一类碱性多肽,对细菌、真菌、病毒和原虫,甚至癌细胞都具有杀伤作用,有望开发成为新一代的抗菌药物。随着抗菌肽家族的不断扩大,其各方面的研究也日益深入。简要综述了昆虫抗菌肽的种类及结构特点、作用机制、生物活性、构效关系、药物开发情况。