ALPHA HELICAL CATHELICIDINS AND HOST DEFENSE

描述(摘自申请者的摘要)：长期目标。至 定义参与先天免疫的抗微生物分子，了解它们如何 工作，并利用这些知识创造新的方法来预防和治疗 感染。--具体目标。1)。从白细胞中提纯人HCAP-18 并检查其特性。2)了解HCAP-18及其小鼠 同系物是由白细胞加工的。3)研究人体的结构 IL-37、小鼠CRIMP-38和血浆中HCAP-18的高分子量形式 和分泌物。4)定义所需的最小多肽结构 铜绿假单胞菌的内毒素结合及抗菌活性。5)检查 脂多糖等刺激对HCAP-18体外表达的影响及检测 脂多糖处理的小鼠体内合成痉挛。6)测量HCAP-18水平 分泌物，并检测其与其他宿主防御肽的相互作用。 方法：研究方法。这些将包括肽的合成，蛋白质的纯化 制备电泳层析法(凝胶渗透、离子交换、 反相高效液相色谱法和亲和力)、计算机模拟、CD和FTIR测量， 抗菌试验、Northern和RT-PCR分析。与健康相关。这个 先天免疫系统是粘膜免疫的关键要素，在粘膜免疫中起主要作用 在预防感染方面的作用。该提案的核心是两个新发现的， 支持抗生素的药物：人HCAP-18及其小鼠同系物， 抽筋了。这些多肽由白细胞组成性地表达，产生 由上皮细胞产生，并存在于人类乳汁、泪液和 精液。它们的C-末端结构域能与内毒素强烈结合，并具有很强的活性 即使在高盐条件下，也能抗铜绿假单胞菌和其他病原体。这个 实验将扩大我们对这些重要多肽的了解，并且 应提供将它们开发为抗生素所需的信息 囊性纤维化的局部支气管肺应用。

Description (adapted from applicant's abstract): Long term objectives. To define antimicrobial molecules involved in innate immunity, learn how they work, and use this knowledge to create novel ways to prevent and treat infections.	Specific aims. 1). To purify human hCAP-18 from leukocytes and secretions and examine its properties. 2) To learn how hCAP-18 and its murine homologue are processed by leukocytes. 3) To study the structures of human LL-37, murine CRAMP-38, and high molecular weight forms of hCAP-18 from plasma and secretions. 4) To define the minimal peptide structure required for LPS-binding and antimicrobial activity against P. aeruginosa. 5) To examine the effects of LPS and other stimuli on in vitro expression of hCAP-18 and examine in vivo synthesis of CRAMP in LPS-treated mice. 6) To measure hCAP-18 levels in secretions, and examine its interactions with other host defense peptides. Methods. These will include peptide synthesis, protein purification by preparative electrophoresis and chromatography (gel permeation, ion exchange, RP-HPLC and affinity), computer modeling, CD and FTIR measurements, antimicrobial testing and Northern and RT-PCR analyses. Health relatedness. The innate immune system is a key element of mucosal immunity that plays a major role in preventing infection. The proposal centers on two newly discovered, pro-antibiotics ("cathelicidins"): human hCAP-18 and its murine homologue, CRAMP. These peptides are expressed constitutively by leukocytes, are produced by epithelial cells, and are found in secretions such as human milk, tears and semen. Their C-terminal domains bind LPS avidly and have potent activity against P. aeruginosa and other pathogens, even under high salt condition. The experiments will expand our knowledge about these important peptides, and should provide the information needed to develop them as antibiotics for topical bronchopulmonary use in cystic fibrosis.