Identifying biological agents that counteract the effect

摘要：炭疽是一种由革兰氏阳性细菌炭疽杆菌引起的疾病，作为生物战剂构成重大威胁。炭疽毒素是一种主要的毒力因子，由三种不同的蛋白质组成，可以帮助细菌逃避免疫系统并在全身感染期间杀死宿主。该毒素由三种蛋白质组成，它们协同作用，包括两种酶，致死因子（LF）和水肿因子（EF），以及保护性抗原（PA）。感染B.anthracis的主要细胞类型是巨噬细胞，临床综合征让人想起脓毒性休克，这可能是由LT和ET反应产生的细胞因子介导的。据报道，ET对人单核细胞具有抑制作用，导致细胞因子网络的破坏。据报道，LT导致小鼠巨噬细胞溶解，释放高水平的NO和TNF-α，以及巨噬细胞信号转导途径的缺陷。然而，关于炭疽毒素影响的研究是矛盾的，主要涉及使用小鼠巨噬细胞，其生物学特性通常与人类巨噬细胞显著不同。我们实验室的重点关注人类单核细胞/巨噬细胞在感染性疾病中的作用以及这些疾病对细胞因子网络的影响。我们建议研究炭疽毒素蛋白单独和组合对人单核细胞/巨噬细胞功能的影响，包括细胞因子的产生。大卫弗鲁赫特博士在DMA/LCB中的研究将确定在受控条件下鼠和人巨噬细胞之间是否存在差异，以及鼠模型是否适合用于炭疽治疗的临床前研究。我们从John Collier博士那里获得了三种炭疽毒素成分的大肠杆菌表达载体。无内毒素炭疽蛋白的表达和纯化正在DMA的Steve Kozlowski博士的实验室进行。在完成这一进程后，将启动上述研究。最终目的是确定细胞因子和细胞因子拮抗剂在治疗B中的治疗潜力。炭疽感染。

Summary: Anthrax, a disease caused by the gram positive bacterium, Bacillus anthracis, poses a significant threat as an agent of biological warfare. Anthrax toxin, consisting of three distinct proteins that help the bacterium evade the immune system and kill the host during systemic infection, is a major virulence factor. The toxin consists of three proteins that act in concert and includes two enzymes, lethal factor (LF) and edema factor (EF), and a protective antigen (PA). The primary cell type infected with B.anthracis is the macrophage and the clinical syndrome is reminiscent of septic shock, which may be mediated by cytokines produced in response to LT and ET. ET has ben reported to have an inhibitory effect on human monocytes, causing he disruption of cytokine networks. LT reportedly causes lysis of murine macrophages, release of high levels of NO and TNF-a, and defects in macrophage signal transduction pathways. However, studies regarding the impact of anthrax toxins are contradictory and have primarily involved the use of murine macrophages, which have biological properties that often differ significantly from human macrophages. The focus of our laboratory concerns the role of human monocytes/macrophages in infectious diseases and the impact of these diseases on cytokine networks. We propose to study the effects of the anthrax toxin proteins alone and in combination on human monocyte/macrophage function, including cytokine production. Studies with Dr. David Frucht in DMA/LCB will determine whether differences exist between murine and human macrophages under controlled conditions and whether the murine model is appropriate for pre-clinical studies for therapeutics proposed for use in the treatment of anthrax. We have obtained E.coli expression vectors for the three anthrax toxin components from Dr. John Collier. The expression and purification of endotoxin-free anthrax proteins is ongoing in the laboratory of Dr. Steve Kozlowski in DMA. Upon completion of this process, the above studies will be initiated. The ultimate goal is to determine the therapeutic potential of cytokines and cytokine antagonists in the treatment of B. anthracis infection.