NOS2 and arginase in visceral leishmaniasis-FIRCA supplement

内脏利什曼病中的 NOS2 和精氨酸酶 - FIRCA 补充剂

• 批准号: 7559198
• 负责人: Peter C. Melby
• 金额: $ 4.02万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-15 至 2011-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7559198
• 关键词: Achyrocline; Address; Animal Model; Animals; Antigens; Area; Biology; CCL17 gene; CCL22 gene; CCL3 gene; Cessation of life; Chronic; Clinical; Collaborations; Colombia; Cutaneous; Cutaneous Leishmaniasis; Disease; Disease Resistance; Disease susceptibility; Epidemic; Epidemiologic Studies; Fostering; Foundations; Genes; Grant; Hamsters; Healed; Human; Hypersensitivity skin testing; Immune response; Immunity; In Vitro; India; Individual; Infection; Interleukin-10; Interleukin-13; Interleukin-4; Investigation; Leishmania; Leishmaniasis; Macrophage Activation; Marriage; Mediating; Metabolic Pathway; Military Personnel; Modeling; Mucocutaneous leishmaniasis; Mus; NOS2A gene; National Research Council; Nature; Parasites; Pathogenesis; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Population; Population Study; Positioning Attribute; Predisposition; Preparation; Preventive; Production; Progressive Disease; Reaction; Relative (related person); Research; Research Activity; Research Infrastructure; Research Personnel; Research Proposals; Resistance; Role; STAT6 gene; Seminal; Small Interfering RNA; Soldier; Staging; Students; Sudan; Testing; Therapeutic Intervention; Training; Travel; United States National Institutes of Health; Universities; Up-Regulation; Vector-transmitted infectious disease; Visceral; Visceral Leishmaniasis; Visit; Work; Writing; acquired immunity; arginase; chemotherapy; cohort; cytokine; design; healing; human disease; impaired capacity; in vitro Model; in vivo; interest; killings; macrophage; meetings; member; monocyte; parent grant; permissiveness; pre-clinical; professor; programs; public health relevance; resistance mechanism; response; university student

DESCRIPTION (provided by applicant): The proposed collaboration between the U.S. investigator (Dr. Peter Melby, UTHSCSA, San Antonio) and the foreign investigator (Dr. Sara Robledo, University of Antioquia, Medellin, Colombia) is an extension of NIH grant R01AI61624, on which Dr. Melby is the PI. Experimental animal studies have identified a dominant role for alternatively activated macrophages (AAMs) in the pathogenesis of cutaneous and visceral leishmaniasis, but their role in human susceptibility and disease has not been determined. The proposed FIRCA grant will extend the experimental animal studies to humans by investigating a previously studied population of individuals who were either classified as resistant (no clinical infection but positive DTH reaction to Leishmania antigen) or susceptible (chronic non-healing cutaneous leishmaniasis). Previous in vitro studies determined that macrophages from susceptible individuals had reduced capacity to control Leishmania infection compared to macrophages from resistant individuals, but the mechanism of this susceptibility is unknown. The overall hypothesis of this proposal is that nonhealing or progressive leishmaniasis is mediated through alternative macrophage activation, which impairs parasite killing. For all of the proposed studies, an in vitro model of Leishmania- infected monocyte-derived macrophages (MDMs), isolated from resistant or susceptible individuals, will be used. The first Specific Aim will test the hypothesis that macrophages from susceptible individuals respond directly to Leishmania infection through a program of alternative activation. The MDMs will be infected with L. (V.) panamensis (dermatropic strain) or L. (L.) donovani (viscerotropic strain), and markers of classical (NO production, NOS2 expression, and CCL3 production) and alternative macrophage activation (arginase activity, IL-10, CCL17, and CCL22 production, and expression of CD23) will be used to determine if Leishmania infection directly induces alternative activation, and if it is associated with susceptibility. The second Specific Aim will test the hypothesis that macrophages from susceptible individuals, when infected with Leishmania, become more sensitive to alternative activation effect of type 2 cytokines. Exposure of uninfected and Leishmania-infected MDMs to IL-4, IL-10, or IL-13 will determine if there is an additive or synergistic effect of the parasites and cytokines in the activation of STAT6 and upregulation of AAM genes. The third Specific Aim will use siRNA- mediated knockdown of STAT6 to test the hypothesis that the program of alternative macrophage activation is STAT6-dependent, and that inhibition of STAT6 activation in susceptible human macrophages will enhance their IFN-3-induced anti-leishmanial response. PUBLIC HEALTH RELEVANCE: Leishmaniasis is a vector borne disease that is endemic throughout much of the world, for which control strategies have largely been unsuccessful or non-sustainable. Cutaneous leishmaniasis is an emerging and re-emerging disease in many parts of the world, and in Colombia the number of cases of cutaneous leishmaniasis has increased dramatically in the past 4 years. Recent epidemics of visceral leishmaniasis have resulted in several hundred thousand deaths in India and Sudan. The poor response to chemotherapy and paucity of available drugs make investigation into the mechanisms of disease, and the identification of preventive or therapeutic interventions, of paramount importance.

描述（由申请人提供）：美国调查员（圣安东尼奥市 UTHSCSA 的 Peter Melby 博士）和外国调查员（哥伦比亚麦德林安蒂奥基亚大学的 Sara Robledo 博士）之间拟议的合作是 NIH 拨款 R01AI61624 的延伸，梅尔比博士是该项目的 PI。实验动物研究已确定替代性激活巨噬细胞 (AAM) 在皮肤和内脏利什曼病的发病机制中起主导作用，但其在人类易感性和疾病中的作用尚未确定。拟议的 FIRCA 拨款将通过调查先前研究的被归类为耐药（无临床感染，但对利什曼原虫抗原 DTH 呈阳性反应）或易感（慢性不愈性皮肤利什曼病）的个体群体，将实验动物研究扩展到人类。先前的体外研究确定，与耐药个体的巨噬细胞相比，易感个体的巨噬细胞控制利什曼原虫感染的能力较低，但这种易感性的机制尚不清楚。该提议的总体假设是，不可治愈或进行性利什曼病是通过替代性巨噬细胞激活介导的，这会损害寄生虫的杀灭作用。对于所有拟议的研究，将使用从耐药或易感个体中分离的利什曼原虫感染的单核细胞衍生巨噬细胞（MDM）的体外模型。第一个具体目标将检验以下假设：易感个体的巨噬细胞通过替代激活程序直接对利什曼原虫感染做出反应。 MDM 将感染 L. (V.) panamensis（亲皮菌株）或 L. (L.) donovani（亲内脏菌株）以及经典标记（NO 产生、NOS2 表达和 CCL3 产生）和替代巨噬细胞激活（精氨酸酶活性、IL-10、CCL17 和 CCL22 产生以及 CD23 表达）将用于确定利什曼原虫感染是否直接诱导替代激活，以及是否与易感性有关。第二个具体目标将检验以下假设：易感个体的巨噬细胞在感染利什曼原虫后，对 2 型细胞因子的替代激活效应变得更加敏感。将未感染和利什曼原虫感染的 MDM 暴露于 IL-4、IL-10 或 IL-13 将确定寄生虫和细胞因子在 STAT6 激活和 AAM 基因上调中是否存在相加或协同效应。第三个具体目标将使用 siRNA 介导的 STAT6 敲除来测试以下假设：替代性巨噬细胞激活程序是 STAT6 依赖性的，并且抑制易感人类巨噬细胞中的 STAT6 激活将增强其 IFN-3 诱导的抗利什曼原虫反应。公共卫生相关性：利什曼病是一种媒介传播的疾病，在世界大部分地区流行，对此的控制策略基本上不成功或不可持续。皮肤利什曼病在世界许多地区是一种新出现和重新出现的疾病，在哥伦比亚，皮肤利什曼病病例数量在过去 4 年中急剧增加。最近内脏利什曼病的流行已导致印度和苏丹数十万人死亡。对化疗的反应不佳和可用药物的缺乏使得研究疾病机制以及确定预防或治疗干预措施变得至关重要。