Mechanisms of Diabetic Susceptibility to Tuberculosis

描述（由申请人提供）：候选人，布伦丹K。Podell，DVM，正在寻求一个指导研究职业发展奖，以帮助他过渡到一个职业生涯作为一个独立的生物医学研究员。Podell博士是一名兽医病理学家，其职业目标是在学术教师职位上从事传染病和免疫学研究，并将于2014年5月完成博士学位。Podell博士已经制定了一个职业发展计划，将促进结核病发病机制，结核病的危险因素， 包括糖尿病，以及研究结核病和糖尿病的新治疗方法。专家教师将促进Podell博士在先进分子生物学，免疫学和蛋白质组学技术和数据解释方面的发展。一个发展计划，强调从教师在新成立的咨询委员会，合作研究的发展，并在granitary和写作卓越的成就的关键反馈将确保博士。Podell博士将由Randall Basaraba博士指导，Randall Basaraba博士是结核病发病机制方面的杰出研究人员，并已成为糖尿病对结核病易感性建模和研究的领导者，这是一个优先研究课题，对全球结核病控制具有重大影响。糖尿病-结核病合并症的研究是本申请中拟议研究的重点，Basaraba博士是该机构最合适的导师。爱德华·胡佛博士将担任共同导师，并通过丰富的经验指导兽医在研究培训和众多的K获奖者;他将支持博士波德尔的过渡到独立。CSU分枝杆菌研究实验室是一个由21名国际公认的分枝杆菌疾病研究人员组成的网络，将为候选人的发展提供出色的环境。糖尿病是结核病（TB）的一个既定的危险因素，但对这种合并症的发病机制知之甚少。由于结核病发病率最高的发展中国家糖尿病发病率迅速上升，传染性和非传染性疾病的综合负担威胁着全球结核病控制。糖尿病的特征是不受控制的高血糖，其加速糖对大分子的不受调节的修饰，导致晚期糖基化终产物（AGEs）的形成。AGEs通过β受体诱导信号传导促进促炎状态，这是糖尿病相关并发症发展的潜在机制。由于（1）在我们的DM-TB合并症动物模型中，高血糖与AGE形成相关;（2）在这些模型中，高血糖诱导的AGE形成与炎症和病理学增加相关;和（3）在结核分枝杆菌（Mtb）感染的糖尿病患者中，控制不良的高血糖症和相关的糖化与促炎细胞因子的增加有关，我们认为AGE的形成和β-内酰胺酶信号传导导致了促炎性免疫反应，这决定了糖尿病患者中更严重的结核病。我们已经开发了第一个2型糖尿病豚鼠模型和唯一经过验证的2型糖尿病-结核病合并症动物模型，这与人类对这种疾病复杂性知之甚少的相似之处。在目标1中，我们已经开发了一种新的策略来靶向这种配体-受体相互作用，并确定AGE-T信号转导是否导致糖尿病豚鼠的TB疾病。我们沿着与合作者一起开发了一种新型高效的抗AGE药物，可减少体内AGE的形成。将使用最近开发的高亲和力小分子抑制剂靶向β受体，该抑制剂已被证明可在体内阻止β信号传导，并将在分离的天然豚鼠可溶性β受体（一种螯合配体并阻止跨膜β信号传导的可溶性受体同种型）的背景下进行解释。通过这一策略，我们将确定AGE形成和/或β-内酰胺酶信号传导是否是糖尿病患者更严重TB的原因。我们已经证明，与患有2型糖尿病的人类相似，在糖尿病豚鼠中，β-淀粉样蛋白表达沿着促炎细胞因子表达升高。在目标2中，我们将确定由于Mtb信号传导而导致的扩增的先天免疫应答是否在Mtb感染早期发生并损害控制细菌生长的能力。通过使用的小分子抑制剂和RNA干扰，我们将证明在糖尿病豚鼠体内的早期细胞因子反应的改变，以及确定是否初始反应和结核分枝杆菌感染的控制受损RAGE介导的扩增的先天性反应在离体分离的肺泡巨噬细胞。我们还表明，糖尿病豚鼠在适应性免疫应答中具有延迟，这对于控制结核分枝杆菌至关重要。由于早期促炎反应损害巨噬细胞功能和适应性免疫的启动，并促进破坏性炎症，因此在目标3中，我们将使用本部门开发的新型肺内RNA干扰技术研究炎症和促炎条件对适应性免疫功能和破坏性炎症的影响。这些目标的成功完成将建立一种新的机制，负责提高糖尿病患者的结核病的严重程度，我们将表明，可以用新的小分子治疗靶向。

DESCRIPTION (provided by applicant): The candidate, Brendan K. Podell, DVM, is pursuing a mentored research career development award to aid in his transition into a career as an independent biomedical researcher. Dr. Podell is a veterinary pathologist with career goals of pursuing research in infectious disease and immunology in an academic faculty position and will complete a PhD degree in May of 2014. Dr. Podell has established a career development plan that will facilitate a research career in tuberculosis pathogenesis, risk factors for tuberculosis, including diabetes, and investigation of novel treatment methods for both tuberculosis and diabetes. Expert faculty will facilitate Dr. Podell's development in advanced molecular biology, immunology and proteomic techniques and data interpretation. A development plan that emphasizes critical feedback from faculty in a newly established advisory committee, development of collaborative research, and achievement of excellence in grantsmanship and writing will ensure Dr. Podell's success during the award period. Dr. Podell will be mentored by Dr. Randall Basaraba, who is an accomplished researcher in tuberculosis pathogenesis and has established himself as a leader in the modeling and study of diabetic susceptibility to tuberculosis, a prioritized research topic with major impact on global tuberculosis control. The study of diabetes-tuberculosis comorbidity is the focus of the proposed research in this application and Dr. Basaraba represents the best-suited mentor at this institution. Dr. Edward Hoover will serve as co-mentor and through extensive experience mentoring veterinarians in research training and numerous K-awardees; he will support Dr. Podell's transition to independence. The CSU Mycobacterial Research Laboratories, a network of 21 internationally recognized investigators in mycobacterial disease, will provide an outstanding environment for development of the candidate. Diabetes is an established risk factor for tuberculosis (TB), however little is known about the pathogenesis of this comorbidity. Due to the rapidly growing prevalence of diabetes in developing countries with the highest incidence of TB, this combined burden of communicable and non-communicable diseases threatens global TB control. Diabetes is characterized by uncontrolled hyperglycemia, which accelerates the unregulated modification of macromolecules by sugars leading to the formation of advanced glycation end products (AGEs). AGEs promote a pro-inflammatory state by inducing signaling through the RAGE receptor, an underlying mechanism for development of diabetes-related complications. Since (1) hyperglycemia is linked to AGE formation in our animal models of DM-TB comorbidity; (2) hyperglycemia-induced AGE formation is associated with increased inflammation and pathology in these models; and (3) poorly controlled hyperglycemia and related glycation are associated with increased pro-inflammatory cytokines in Mycobacterium tuberculosis (Mtb) infected diabetic humans, we propose that AGE formation and RAGE signaling lead to a pro-inflammatory immune response that dictates more severe TB in diabetics. We have developed the first guinea pig model of type 2 diabetes and the only validated animal model of type 2 diabetes-tuberculosis comorbidity, which shows important similarities to what little is known about this disease complex in humans. In Aim 1, we have developed a novel strategy to target this ligand-receptor interaction and determine if AGE-RAGE signaling worsens TB disease in diabetic guinea pigs. Along with collaborators, we have developed a novel and highly potent class of anti-AGE drugs that will reduce AGE formation in vivo. The RAGE receptor will be targeted using a recently developed, high affinity small molecule inhibitor proven to prevent RAGE signaling in vivo and will be interpreted in the context of isolated native guinea pig soluble RAGE (sRAGE), a soluble receptor isoform that sequesters ligands and prevents transmembrane RAGE signaling. Through this strategy, we will determine if AGE formation and/or RAGE signaling are responsible for more severe TB in diabetics. We have shown that RAGE expression along with pro-inflammatory cytokine expression, similar to humans with type 2 diabetes, are elevated in diabetic guinea pigs. In Aim 2, we will determine if an amplified innate immune response due to RAGE signaling occurs early in Mtb infection and impairs the ability to control bacterial growth. Through use of the small molecule RAGE inhibitor and RNA interference, we will demonstrate alterations in the early cytokine response in vivo in diabetic guinea pigs as well as determine if the initial response and control of Mtb infection is impaired by RAGE-mediated amplification of the innate response in ex vivo isolated alveolar macrophages. We have also shown that diabetic guinea pigs have a delay in the adaptive immune response that is critical for control of Mtb. Since an early pro-inflammatory response impairs macrophage function and priming of adaptive immunity, and promotes destructive inflammation, in Aim 3, we will investigate the impact of RAGE and pro-inflammatory conditions on onset of adaptive immune function and damaging inflammation using novel intrapulmonary RNA interference techniques developed in our department. Successful completion of these aims will establish a novel mechanism responsible for heightened severity of TB in diabetics, which we will show can be targeted therapeutically with novel small molecules.