MICROBICIDAL PROTEINS FROM PLATELETS

描述（改编自申请人摘要）：血管内感染 包括感染性心内膜炎、心肌动脉瘤、血管导管， 血液透析部位败血症和血管移植物和假体感染。 的 血管内感染的发生率在20世纪90年代急剧增加， 在过去十年中， 感染. 鉴于越来越多地使用留置生物材料， 作为人工心脏瓣膜，长期使用留置导管， 血管内支架，血管内感染的发生率将可能 继续增长。 此外，多种抗药性病原体， 经常引起这些感染（例如，金黄色葡萄球菌）现在正在 与干扰频率隔离。 总的来说，这些事实强调 迫切需要更好地了解宿主防御 血管内感染 在这方面有一个更清晰的宿主防御概念 可能揭示其增强的机会，或新的目标， 预防或治疗血管内感染。 血小板是最早和最主要的细胞之一， 血管内感染 伊曼博士和他的同事最近 分离了一个家族的血小板杀微生物蛋白（PMPs）， 有助于血小板的抗微生物特性。 但他们的 血小板释放、比较结构和杀微生物活性 尚未建立。 因此，本提案的具体目标 旨在解决以下问题：i）微生物或 与血管内感染相关的血小板激动剂引起PMP 释放？; ii）分泌型和分泌型之间的结构关系是什么？ 非分泌型PMP形式？和iii）比较的杀微生物剂是什么 不同形式的PMP的能力？ 他们将决定PMP存在的位置 用颗粒分离和免疫定位方法检测血小板中的血小板。 他们将使用一组微生物和血小板激动剂， 感染，以检查引起PMP释放。 他们将决定， 比较的组成，一级结构，和构象 使用蛋白质的代表性分泌和非分泌PMP形式 生物化学和分子生物学技术。 他们还将确定 并比较杀菌谱、效力、动力学和相互作用 分泌型和非分泌型PMP形式的体外研究， 血液病原体沿着PMP敏感和耐药S.金黄色 成对作为探针。 这些调查的长期目标是促进我们的理解 PMPs和血小板在宿主防御血管内 感染 这些知识可以提供新的策略， 管理血管内感染。 此外，这些研究还可以提供 适用于更广泛的发病机制问题的信息，如微生物 与生物材料的相互作用。 此外，这些研究可能揭示 关于PMP结构和功能重要新信息， 用于设计有效的新型抗菌剂。 这些潜在 应用是本项目的重点。

DESCRIPTION (Adapted from applicant's abstract): Endovascular infections include infective endocarditis, mycotic aneurysm, vascular catheter and hemodialysis site sepsis, and vascular graft and prosthesis infections. The incidence of endovascular infections has increased dramatically over the past decade and now represent a significant proportion of all serious infections. In light of the increasing use of indwelling biomaterials such as artificial cardiac valves, prolonged use of indwelling catheters, and endovascular stents, the incidence of endovascular infections will likely continue to grow. Moreover, multiple antibiotic-resistant pathogens which often cause these infections (eg., Staphylococcus aureus) are now being isolated with disturbing frequency. Collectively, these facts underscore the urgent need for greater understanding of host defense against endovascular infection. A clearer concept of host defense in this regard may reveal opportunities for its augmentation, or novel targets for prevention or treatment of endovascular infection. Platelets are among the earliest and most predominant cells at sites of endovascular infection. Dr. Yeaman and his colleagues have recently isolated a family platelet microbicidal proteins (PMPs), which may contribute to the antimicrobial properties of platelets. However, their release from platelets, comparative structures and microbicidal activities have not been established. Therefore, the Specific Aims of this proposal are designed to address the following questions: i) do microorganisms or platelet agonists associated with endovascular infection elicit PMP release?; ii) what is the structural relationship between secreted and non-secreted PMP forms?; and iii) what are the comparative microbicidal capacities of differing forms of PMP? They will determine where PMPs exist in the platelet using granule isolation and immunolocalization methods. They will use a panel of microorganisms and platelet agonists relevant to infection to examine which elicit PMP release. They will determine and compare the compositions, primary structures, and conformations of representative secreted and non-secreted PMP forms using protein biochemistry and molecular biological techniques. They will also determine and compare the microbicidal spectra, potencies, kinetics, and interactions of secreted and non-secreted PMP forms in vitro using a panel of common bloodstream pathogens along with PMP-sensitive and -resistant S. aureus pairs as probes. The long range goal of these investigations is to advance our understanding of the role of PMPs and platelets in host defense against endovascular infection. This knowledge may provide novel strategies for preventing or managing endovascular infections. Furthermore, these studies may provide information applicable to broader issues of pathogenesis, such as microbe interaction with biomaterials. In addition, these studies may uncover important new information regarding PMP structure and function that may serve in designing potent new antimicrobial agents. These potential applications underlie the focus of this project.