ALPHA HELICAL CATHELICIDINS AND HOST DEFENSE

描述（改编自申请人的摘要）：长期目标。到 定义参与先天免疫的抗菌分子，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。&# 9、具体目标。1）。为了从白细胞中纯化人hCAP-18， 分泌物并检查其属性。2)为了了解hCAP-18和其小鼠 同源物由白细胞加工。3)研究人体的结构 来自血浆的LL-37、鼠CRAMP-38和高分子量形式的hCAP-18 和分泌物。4)为了定义所需的最小肽结构， 针对铜绿假单胞菌的LPS结合和抗微生物活性。5)审查 LPS和其他刺激对hCAP-18体外表达的影响并检查 LPS处理的小鼠中CRAMP的体内合成。6)为了测量hCAP-18水平， 分泌物，并检查其与其他宿主防御肽的相互作用。 方法.这些将包括肽合成，蛋白质纯化， 制备电泳和色谱法（凝胶渗透，离子交换， RP-HPLC和亲和性），计算机建模，CD和FTIR测量， 抗微生物测试和北方和RT-PCR分析。健康相关性。的 先天免疫系统是粘膜免疫的关键要素， 预防感染的作用。该提案集中在两个新发现的， 前抗生素（“凯萨林菌素”）：人hCAP-18及其鼠同源物， 抽筋了这些肽由白细胞组成性表达， 由上皮细胞，并发现在分泌物，如母乳，眼泪和 精液它们的C-末端结构域与LPS结合并具有强活性 抗铜绿假单胞菌和其他病原体，即使在高盐条件下。的 实验将扩大我们对这些重要肽的知识， 应该提供开发它们作为抗生素所需的信息， 囊性纤维化的局部支气管肺栓塞治疗。

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.