A cyclic di-GMP signaling system of spores of Bacillus anthracis

 描述（由申请方提供）：炭疽芽孢杆菌是一种内孢子形成的人畜共患病细菌，作为生物恐怖剂受到严重关注。孢子进入人类宿主的途径决定了所导致疾病的性质，皮肤、胃肠道或肺部。胃肠道和肺炭疽病与高死亡率相关。B的组成。炭疽孢子，特别是其间隙层和外孢壁层，是不完全了解。酶，包括丙氨酸消旋酶，肌苷偏好核苷水解酶，和一氧化氮合酶，发现在孢子外被，间隙和外孢壁层。这些酶被认为在孢子萌发和防御宿主先天免疫系统中起作用。我们已经确定了与B孢子中环二GMP水平调节相关的蛋白质的存在。炭疽病环二GMP是一种重要的调节剂，已被确定在许多细菌病原体。它是许多毒力属性的关键调节剂，包括生物膜形成、运动性、细胞内存活、表面粘附的表达、皮利的表达、对氧化应激的抗性和宿主免疫应答的调节。这种环核苷酸调节剂在孢子生物学（孢子形成或萌发）中的作用尚未报道。我们建议研究GGDEF结构域的蛋白质，其表达谱和/或蛋白融合研究表明，它们是孢子蛋白。对这些决定因子之一的初步研究表明对孢子成熟有影响。在这个项目中，我们将确定这些GGDEF蛋白在孢子内的位置，对孢子结构和功能的影响与这些蛋白的单独和组合损失有关，以及对巨噬细胞培养物和小鼠感染模型中孢子生物学的影响。这些实验的目的是确定GGDEF蛋白对孢子形成、萌发和毒力的作用。由于孢子是这种人畜共患病病原体的感染形式，因此这一信息对我们了解B很重要。炭疽感染过程，并可能确定潜在的目标，治疗干预对B中的初始步骤。炭疽感染。从这项研究中获得的信息可能有更广泛的适用性，以了解其他内孢子形成细菌病原体的感染过程。

 DESCRIPTION (provided by applicant): Bacillus anthracis is an endospore-forming zoonotic bacterium of significant concern as a bioterrorism agent. The route by which the spore gains access to a human host defines the nature of the resulting disease, cutaneous, gastrointestinal, or pulmonary. Gastrointestinal and pulmonary anthrax are associated with high mortality rates. The composition of the B. anthracis spore, especially its interspace and exosporium layers, is incompletely understood. Enzymes, including alanine racemase, inosine preferring nucleoside hydrolase, and nitric oxide synthase, are found in the outer spore coat, interspace, and exosporium layers. These enzymes are thought to function in spore germination and defense against the host innate immune system. We have identified the presence of proteins associated with the regulation of cyclic di-GMP levels in spores of B. anthracis. Cyclic di-GMP is an important regulator that has been identified in a number of bacterial pathogens. It is a critical regulator of a number of virulence attributes including biofilm formation, motility, intracellular survival, expression of surface adhesions, expression of pili, resistance to oxidative stress, and modulation of the host immune response. A role for this cyclic nucleotide regulator in spore biology, either sporulation or germination, has not been reported. We propose to study GGDEF domain-containing proteins whose expression profile and/or protein fusion studies indicate that they are spore proteins. Initial studies with one of these determinants have shown an effect on spore maturation. In this project, we will determine the location within the spores for these GGDEF proteins, the effects on spore structure and function associated with loss of these proteins both singly and in combination, and the effects on spore biology in macrophage cell cultures and a mouse model of infection. The goals of these experiments are to determine the roles of the GGDEF proteins on sporulation, germination, and virulence. Because the spore is the infectious form of this zoonotic pathogen, this information is important to our understanding of the B. anthracis infectious process and may identify potential targets for therapeutic intervention against the initial steps in B. anthracis infections. Information obtained from this study may have broader applicability to understanding the infectious process of other endospore-forming bacterial pathogens.