Inhibition of Anthrax Lethal Factor by alpha-defensins

α-防御素对炭疽致死因子的抑制

基本信息

批准号：
7557627
负责人：
WUYUAN LU
金额：
$ 28.45万
依托单位：
UNIVERSITY OF MARYLAND BALTIMORE
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-12-15 至 2011-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7557627
关键词：
Affinity Labels Alanine Algorithms Amino Acids Animals Anthrax antitoxin Anthrax disease Antigens Antimicrobial Cationic Peptides Antitoxins Bacillus anthracis Bacillus anthracis spore Bacteria Binding Cell membrane Cessation of life Class Classification Cleaved cell Complex Cultured Cells Cytolysis Cytosol Defensins Dissociation Enzyme Kinetics Enzymes Epitopes Equilibrium Family Generations Human Immune Inbred BALB C Mice Infection MAP Kinase Gene MAPK Signaling Pathway Pathway Maps Mass Spectrum Analysis Metalloproteases Microbe Mitogen-Activated Protein Kinases Molecular Mus Mutagenesis Mutation Numbers Pathogenesis Phagocytes Phosphotransferases Play Positioning Attribute Protein Kinase Proteins Range Reporting Role Scanning Signal Pathway Signal Transduction Spectrum Analysis Surface Plasmon Resonance Symptoms Techniques Testing Therapeutic Thermodynamics Virulence Factors Virus affinity labeling alpha-Defensins analog anthrax lethal factor anthrax protective factor anthrax toxin base cell killing cytotoxicity design drug development edema factor fungus improved in vivo inhibitor/antagonist killings macrophage member neutrophil novel pathogen prevent small molecule therapeutic target uptake

项目摘要

DESCRIPTION (provided by applicant): Anthrax toxin consists of three proteins secreted by Bacillus anthracis - protective antigen (PA), edema factor (EF) and lethal factor (LF). LF is a Zn2+dependent metalloprotease that cleaves members of the mitogen-activated protein kinase (MAPKK) family, blocking the MARK signaling pathway in professional phagocytes. The binary complex of PA and LF alone, termed lethal toxin or LeTx, is sufficient to induce death of target cells and kill experimental animals, manifesting the symptoms associated with anthrax. As one of the primary virulence factors in the pathogenesis of anthrax, LF has become an important therapeutic target for drug development. A number of small-molecule-based inhibitors of LF have been shown to be able to neutralize cytotoxicity of LeTx in cell cultures and lethality of LeTx in animal trials, promising potential therapeutic value in the treatment of anthrax infection. Human neutrophil a-defensins (HNPs) are members of a growing family of small cationic antimicrobial peptides that kill a broad range of microbes such as bacteria, fungi and viruses, playing an important role in the innate immune defense against infectious pathogens. Kaufmann and colleagues recently discovered that HNP1 non-competitively inhibits LF, preventing cleavage of a MAPKK and restoring impaired MAPK signaling in LeTx-treated macrophages (Kim et al., 2005). Further, HNP1 rescued murine macrophages from B. anthracis-induced cytotoxicity, and in vivo treatment with HNP1-3 protected mice against the fatal consequences of LeTx (Kim et al 2005). In a subsequent report, Mayer-Scholl et al. (2005) demonstrated that B. anthracis spores engulfed by human neutrophils and germinated intracellularly can be effectively killed by HNPs. These findings raise the possibility that a-defensins may be developed as a novel class of antitoxins to combat anthrax infection. Despite the therapeutic potential of a-defensin-based antitoxins for anthrax treatment, the molecular basis for the inhibition of LF by a-defensins remains poorly understood. In this proposal, we seek to decipher the sequence rules and structural determinants that dictate the inhibition of LF by a-defensins, and to design second-generation defensin molecules with significantly improved inhibitory activity.

描述（由申请人提供）：炭疽毒素由三种由炭疽芽孢杆菌 - 保护性抗原（PA），水肿因子（EF）（EF）和致命因子（LF）分泌的三种蛋白质。 LF是Zn2+依赖性金属蛋白酶，它裂解了有丝分裂原激活蛋白激酶（MAPKK）家族的成员，阻止了专业吞噬细胞中的标记信号通路。单独使用PA和LF的二元复合物称为致命的毒素或LETX，足以诱导靶细胞死亡并杀死实验动物，表现出与炭疽相关的症状。作为炭疽病发病机理的主要毒力因素之一，LF已成为药物发育的重要治疗靶标。在动物试验中，许多基于LF的小分子抑制剂已显示能够中和LETX的细胞毒性和LETX的致死性，并有望在治疗炭疽病感染方面具有潜在的治疗价值。人类嗜中性粒细胞A-防御素（HNP）是日益增长的小阳离子抗菌肽家族的成员，它们杀死了多种微生物，例如细菌，真菌和病毒，在对感染性病原体的先天免疫防御中发挥了重要作用。 Kaufmann及其同事最近发现，HNP1非功能抑制LF，防止MAPKK裂解并恢复LETX处理的巨噬细胞中的MAPK信号传导受损（Kim等，2005）。此外，HNP1从炭疽芽孢杆菌诱导的细胞毒性中救出了鼠巨噬细胞，并用HNP1-3保护小鼠在体内治疗LETX的致命后果（Kim等，2005）。在随后的报告中，Mayer-Scholl等人。（2005年）证明，炭疽芽孢杆菌孢子被人类嗜中性粒细胞吞没并细胞内发芽可以被HNP有效杀死。这些发现提出了一种可能形成一种新型抗毒素来应对炭疽感染的新型抗毒素的可能性。尽管基于A-二防御素的抗毒素对炭疽治疗具有治疗潜力，但A-二防御蛋白抑制LF的分子基础仍然很少了解。在此提案中，我们试图解释序列规则和结构决定因素，这些决定因素决定了A-抗甲蛋白抑制LF的抑制作用，并设计了具有显着改善抑制活性的第二代防御素分子。