Immune control of tuberculosis by IFN-gamma-inducible LRG-47

IFN-γ 诱导型 LRG-47 对结核病的免疫控制

• 批准号: 7470658
• 负责人: John David MacMicking
• 金额: $ 31.53万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7470658
• 关键词: Accounting; Antigens; Behavior; Cause of Death; Cell Fractionation; Cells; Clinical; Cytokine Activation; Dendritic Cells; Detection; Disease; Drug Delivery Systems; Event; Family; Family member; Genes; Genetic Screening; Glean; Growth; Guanosine; Guanosine Triphosphate Phosphohydrolases; HIV; HIV-1; Host Defense; Host resistance; Human; Image; Immune; Immune response; Immunity; Immunocompetent; Immunologist; Individual; Infection; Interferon Type II; Lesion; Life; Link; Location; Microscopy; Molecular; Mus; Mutation; Mycobacterium tuberculosis; NOS2A gene; Numbers; Organelles; Outcome; Pathway interactions; Phagosomes; Pharmacotherapy; Plague; Play; Population; Proteins; Purpose; Resolution; Role; Route; Surrogate Markers; T-Lymphocyte; Thinking; Time; Tuberculosis; Vaccine Design; Virulence Factors; cytokine; human AKAP13 protein; human NOS2A protein; insight; killings; macrophage; mammalian genome; member; molecular array; mouse model; novel; pandemic disease; pathogen; progesterone 11-hemisuccinate-(2-iodohistamine); programs; prospective; protective effect; response; trafficking; vaccine efficacy

DESCRIPTION (provided by applicant): Natural mutations in humans and introduced mutations in mice have unequivocally demonstrated the importance of interferon-gamma (IFN-gamma) for the control of tuberculosis (TB). How this cytokine exerts its protective effects is thought to owe much to the broad transcriptional programs it activates within Mycobacterium tuberculosis (Mto)-infected macrophages and dendritic cells. Here as many as 1,300 genes may be engaged. Prominent within this group is a new family of 47kDa guanosine 5'-triphosphatases (p47 GTPases) that confers host resistance to a number of human pathogens. At least one member of this family - LRG-47 - appears essential for combating TB in experimental mouse models. Preliminary evidence suggests that LRG-47 operates at the level of the infected cell via a mechanism distinct from all known tuberculocidal pathways, linking cytokine activation with phagolysomal fusion, events that are required for bacterial killing and which may enable Mtb antigens to be cross-presented. It is the purpose of this proposal to build on these initial observations by pursuing the following aims: (1) Characterize the intracellular location and trafficking behavior of mouse and human LRG-47 within Mtb-infected cells. Here a combination of high-resolution imaging and cell fractionation will be used to identify the LRG-47-positive compartment(s) and its recruitment to the nascent Mtb phagosome. (2) Define the molecular determinants of LRG-47 function in response to Mtb. Relocation of LRG-47 to the Mtb phagosome and subsequent remodeling of this organelle is likely to enlist other host proteins. Isolating LRG-47-interacting partners, the functional domains involved and their consequences for immunity will be dissected with an array of molecular, cellular and structural approaches. (3) Uncover Mtb-encoded pathways that counter LRG-47 - dependent immunity. Genetic screens conducted to identify bacterial components interfering with LRG-47 should yield further insights into how this GTPase operates. It could also uncover prospective drug targets. Information gleaned from these approaches will provide a paradigm for other members of the p47 GTPase family that is rapidly emerging as one of the most powerful host defense repertoires in the mammalian genome.

描述（由申请方提供）：人类中的自然突变和小鼠中的引入突变已明确证明干扰素-γ（IFN-γ）对控制结核病（TB）的重要性。这种细胞因子如何发挥其保护作用被认为是由于它在结核分枝杆菌（Mto）感染的巨噬细胞和树突状细胞内激活了广泛的转录程序。这里可能有多达1,300个基因参与其中。在该组中突出的是47 kDa鸟苷5 '-三磷酸酶（p47 GTP酶）的新家族，其赋予宿主对许多人类病原体的抗性。这个家族中至少有一个成员-- LRG-47 --在实验小鼠模型中似乎对抗击结核病至关重要。初步证据表明，LRG-47通过与所有已知的杀结核途径不同的机制在感染细胞水平上起作用，将细胞因子活化与吞噬溶酶体融合联系起来，这是细菌杀伤所需的事件，可能使Mtb抗原交叉呈递。本提案的目的是通过追求以下目标来建立这些初步观察结果：（1）表征小鼠和人LRG-47在Mtb感染细胞内的细胞内定位和运输行为。在此，将使用高分辨率成像和细胞分级分离的组合来鉴定LRG-47阳性隔室及其向新生Mtb吞噬体的募集。(2)定义LRG-47响应结核分枝杆菌功能的分子决定因素。LRG-47的迁移到结核分枝杆菌吞噬体和随后的重塑这个细胞器可能会招募其他宿主蛋白质。分离LRG-47相互作用的合作伙伴，所涉及的功能结构域及其对免疫的后果将与一系列的分子，细胞和结构的方法进行解剖。(3)发现Mtb编码的途径，对抗LRG-47依赖性免疫。进行遗传筛选，以确定干扰LRG-47的细菌成分，应该产生进一步的见解，这种GTdR如何运作。它还可以发现潜在的药物靶点。从这些方法中收集的信息将为p47 GTdR家族的其他成员提供一个范例，该家族正迅速成为哺乳动物基因组中最强大的宿主防御系统之一。