DNA Minor Groove-binding Drugs and Food-borne Pathogens

说明（申请方提供）：生物战剂的扩散有可能造成严重的发病率和死亡率，并引起公众恐慌。因此，必须进一步调查如何处理和预防生物战的有害后果。该提案的重点是食源性病原体，特别是沙门氏菌属和大肠杆菌的B类细菌病原体及其毒素。与其他生物传染性病原体相比，这些微生物需要较少的专业知识来处理，并且通过污染食品，它们有可能在大规模人群和广泛的地理区域中造成疾病爆发。这些微生物有可能从胃肠道传播到血液中，导致菌血症和内毒素血症，这对患者造成毁灭性的后果。在过去的几年里，我们一直对伤寒沙门氏菌和大肠杆菌内毒素的病理生理学感兴趣。在最近的研究中，我们有初步的数据表明，一种天然存在的化合物，偏端霉素A，可能会改善内毒素血症小鼠模型的结果。已知Distamycin A与AT富集区的DNA小沟结合，其作用部分通过破坏转录因子（如核因子（NF）-κ B和干扰素调节因子（IRF））与DNA的结合而发生。我们的总体假设是，DNA小沟结合药物将抑制基因的表达，这些基因在内毒素反应过程中对炎症和血管张力的调节起关键作用，从而为食源性病原体毒素提供了一种新的治疗选择。因此，本提案的目标是：1）确定与DNA小沟AT富集区结合的药物是否改善暴露于食源性病原体伤寒沙门氏菌和大肠杆菌的内毒素的小鼠的结果，2）鉴定由DNA小沟结合药物调节的特定基因，其有助于改善内毒素暴露期间的反应，以及3）表征DNA小沟结合药物改变基因表达从而导致内毒素暴露期间改善结果的机制。

DESCRIPTION (provided by applicant): Dispersion of biological warfare agents has the potential of causing significant morbidity and mortality, and public panic. Thus, further investigation into the treatment and prevention of the detrimental consequences of biological warfare is imperative. The focus of this proposal is food-borne pathogens, particularly category B bacterial pathogens of the Salmonella species and Escherichia coli, and their toxins. Compared with other biological infectious agents, these organisms require less expertise to handle, and by contaminating food products, they have the potential to produce disease outbreaks in large groups of people and over broad geographic regions. These organisms have the potential to spread from the gastrointestinal tract into the blood stream, resulting in bacteremia and endotoxemia, which has devastating consequences in patients. Over the past several years we have been interested in the pathophysiology of endotoxin from Salmonella typhi and Escherichia coli. In recent investigations, we have preliminary data to suggest a naturally occurring compound, distamycin A, may improve outcome in a mouse model of endotoxemia. Distamycin A is known to bind to the minor groove of DNA in AT-rich regions, and its effect occurs in part by disrupting the binding of transcription factors to DNA such as nuclear factor (NF)-kappa B and interferon regulatory factors (IRFs). Our overall hypothesis is that DNA minor groove-binding drugs will suppress the expression of genes that play a critical role in the regulation of inflammation and vascular tone during an endotoxin response, and thus provide a novel therapeutic option for toxins of food-borne pathogens. Thus, the goals of this proposal are: 1) to determine whether drugs that bind to AT-rich regions of the minor groove of DNA improve outcome in mice exposed to endotoxin of the food-borne pathogens, Salmonella typhi and Escherichia coli, 2) to identify specific genes, regulated by DNA minor groove-binding drugs, that contribute to an improved response during endotoxin exposure, and 3) to characterize the mechanisms by which DNA minor groove-binding drugs alter gene expression leading to improved outcome during endotoxin exposure.