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（由申请人提供）：人类的自然突变和小鼠的引入突变已明确证明了干扰素-γ（IFN-γ）对于控制结核病（TB）的重要性。这种细胞因子如何发挥其保护作用被认为很大程度上归功于它在结核分枝杆菌 (Mto) 感染的巨噬细胞和树突状细胞中激活的广泛转录程序。这里可能涉及多达 1,300 个基因。该组中最突出的是一个新的 47kDa 鸟苷 5'-三磷酸酶 (p47 GTPases) 家族，它赋予宿主对多种人类病原体的抵抗力。该家族的至少一个成员——LRG-47——似乎对于实验小鼠模型中对抗结核病至关重要。初步证据表明，LRG-47 在受感染细胞水平上发挥作用，其机制不同于所有已知的杀结核途径，将细胞因子激活与吞噬溶酶体融合联系起来，这是杀死细菌所需的事件，并且可能使 Mtb 抗原能够交叉呈递。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）表征小鼠和人类 LRG-47 在 Mtb 感染细胞内的细胞内位置和运输行为。在这里，高分辨率成像和细胞分级分离的组合将用于识别 LRG-47 阳性区室及其招募到新生 Mtb 吞噬体的情况。 (2) 定义 LRG-47 响应 Mtb 功能的分子决定因素。 LRG-47 重新定位到 Mtb 吞噬体以及随后对该细胞器的重塑可能会招募其他宿主蛋白。将通过一系列分子、细胞和结构方法来分离 LRG-47 相互作用伙伴、所涉及的功能域及其对免疫的影响。 (3) 发现对抗 LRG-47 依赖性免疫的 Mtb 编码途径。为鉴定干扰 LRG-47 的细菌成分而进行的遗传筛选应该可以进一步了解这种 GTP 酶的运作方式。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 GTPase 家族的其他成员提供范例，该家族正迅速成为哺乳动物基因组中最强大的宿主防御库之一。