MICROBICIDAL PROTEINS FROM PLATELETS

描述(摘自申请者的摘要)：血管内感染 包括感染性心内膜炎、霉菌性动脉瘤、血管导管和 血液透析部位败血症，血管移植物和假体感染。这个 血管内感染的发生率在过去几年里急剧增加。 过去十年，现在在所有严重的 感染。鉴于留置生物材料的使用日益增多，如 如人工心脏瓣膜，长时间使用留置导管，以及 血管内支架置入后，血管内感染的发生率很可能 继续增长。此外，多重耐药病原体 经常引起这些感染(如金黄色葡萄球菌)现在正在 以令人不安的频率隔离。总而言之，这些事实强调了 迫切需要更好地了解宿主防御 血管内感染。在这方面更明确的东道主防御概念 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。 血小板是最早也是最主要的细胞之一。 血管内感染。耶曼博士和他的同事们最近 分离出一个家族的血小板杀微生物蛋白(PMPs)，它可能 有助于提高血小板的抗菌性能。然而，他们的 血小板释放、比较结构和杀菌活性 还没有建立起来。因此，这项建议的具体目的是 旨在解决以下问题：i)微生物或 血管内感染相关的血小板激动剂引发PMP 释放？；ii)分泌和释放之间的结构关系是什么 非分泌型PMP；以及iii)相对杀菌剂是什么？ 不同形式的PMP的能力？他们将确定PMP存在的位置 在血小板中采用颗粒分离和免疫定位的方法。 他们将使用一组微生物和血小板激动剂 检测哪种感染会导致PMP的释放。他们将决定和 比较其组成、一级结构和构象 典型的分泌型和非分泌型PMP使用蛋白质 生物化学和分子生物学技术。他们还将确定 并比较杀微生物剂的光谱、效力、动力学和相互作用 在体外使用一组常见的 血液病原体与PMP敏感和耐药金黄色葡萄球菌 成对作为探针。 这些调查的长期目标是增进我们对 PMPs和血小板在宿主血管内防御中的作用 感染。这一知识可以提供新的策略来预防或 管理血管内感染。此外，这些研究可能会提供 适用于更广泛的致病机理问题的信息，如微生物 与生物材料的相互作用。此外，这些研究可能会揭示 有关PMP结构和功能的重要新信息，可能 服务于设计有效的新型抗菌剂。这些潜力 应用程序是本项目的重点。

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.