Cell wall protein in Bacillus anthracis pathogenesis

描述（由申请人提供）：炭疽是一种古老的疾病，与科学家和公众都有着重生的意义。为了对抗这个老敌人，必须在其发病机理的分子水平上清楚和充分地了解病原体炭疽芽孢杆菌。许多革兰氏阳性病原菌具有细胞壁锚定蛋白（CWAP），这些蛋白对于毒力至关重要，并且是优秀的候选疫苗。以此类推，B.炭疽病可能显示出同样的相关性和效用。分析了B。炭疽菌基因组揭示了9个以前未表征的CWAPs。初步研究表明，这些公认的特定巨噬细胞靶之一的重组片段。炭疽菌在炭疽病的形成过程中起着核心作用。另外两种CWAP被发现与胶原蛋白结合，胶原蛋白是皮肤炭疽病发展的皮肤的主要成分。这些发现共同支持了B.炭疽菌在其发病机制中具有重要意义。 本建议的两个具体目标是确定化学武器工作人员方案在B的互动中的作用。炭疽病与1）巨噬细胞和2）主要皮肤成分即，胶原蛋白和成纤维细胞。为了实现这些目标，将为9个CWAP中的每一个产生缺失突变体。将评价突变体与巨噬细胞结合、被巨噬细胞吞噬和在巨噬细胞内存活的能力，以及它们粘附和侵入人真皮成纤维细胞的能力。相应的突变体也将用于确定两种胶原结合CWAP中的每一种在B粘附中的相关性。从炭疽菌到胶原蛋白为了确认CWAP的功能，将缺失的基因进行互补，然后在异源宿主中表达。随后将鉴定它们在宿主细胞中的分子靶标。将来，这些蛋白质在B。将与德克萨斯大学医学院的Theresa Koehler博士和新墨西哥州大学的Rick里昂博士合作，在动物模型中评估炭疽菌的毒力。长期目标是阐明这些蛋白质的生物学功能，它们与宿主的分子相互作用及其作为疫苗和药物靶点的潜力。这些信息可能会提高对B感染机制的理解。炭疽病，并可能提供新的有效方法来打击炭疽病的祸害。

DESCRIPTION (provided by applicant): Anthrax is an old disease with re-born relevance to both scientists and public. To fight this old foe, the causative organism, Bacillus anthracis, must be understood clearly and fully at the mechanistic molecular level of its pathogenesis. Many Gram-positive pathogenic bacteria possess cell wall anchored proteins (CWAPs) that are critical for virulence and are excellent vaccine candidates. By analogy, the CWAPs of B. anthracis are likely to show equal relevance and utility. Analysis of the B. anthracis genome revealed nine previously uncharacterized CWAPs. Preliminary studies indicated a recombinant fragment of one of these recognized specific macrophage targets. Macrophages play a central role in the establishment of anthrax. Two additional CWAPs were found to bind collagen, which is a major component of the skin where cutaneous anthrax develops. Together these findings support the hypothesis that CWAPs of B. anthracis are significant in its pathogenesis. The two specific aims of this proposal are to determine the roles of CWAPs in the interaction of B. anthracis with 1) macrophages and 2) major skin components i.e., collagen and fibroblasts. To achieve these aims, deletion mutants will be generated for each of the nine CWAPs. The mutants will be evaluated for their ability to associate with, be engulfed by and survive within macrophages, as well as their ability to adhere and invade human dermal fibroblasts. The respective mutants will also be used to determine the relevance of each of the two collagen-binding CWAPs in the adherence of B. anthracis to collagen. To confirm the function of the CWAPs, the deleted genes will be complemented then expressed in a heterologous host. Their molecular targets in the host cells will subsequently be identified. In the future, the effect of these proteins in B. anthracis virulence will be evaluated in an animal model in collaboration with Dr. Theresa Koehler at University of Texas Medical School, and Dr. Rick Lyons at University of New Mexico. The long-term objectives are to elucidate the biological functions of these proteins, their molecular interactions with the host and their potential as vaccine and drug targets. The information will likely improve the understanding of the infection mechanisms of B. anthracis, and may provide novel effective ways to combat the scourge of anthrax.