T cell responses to CD1-restricted lipids in tuberculosis

描述（由申请人提供）：结核分枝杆菌仍然是一种具有全球重要性的病原体，目前感染16亿人，每年造成170万人死亡。人类对感染的成功反应主要依赖于T细胞，以前认为T细胞仅由与MHC蛋白结合的肽抗原激活。然而，CD1蛋白是分枝杆菌和其他病原体激活T细胞的新发现途径。CD1蛋白在树突状细胞上以高度调控的方式表达，在那里它们捕获分枝杆菌脂质抗原并提呈给T细胞。CD1蛋白存在于所有哺乳动物中，因此可能在免疫反应中具有不可或缺的功能。虽然CD1d和NK T细胞的基本功能已经被很好地理解，但人类CD1a、CD1b和CD1c蛋白的自然功能尚不清楚。在发现了由CD1a（双脱氧菌素）、CD1b（葡萄糖单菌酸盐）和CD1c（甘露糖酰光菌酮）呈递的脂质抗原后，本更新方案使用了一个完善的模型系统，首次确定了这些抗原接触T细胞受体的一般分子机制以及人类患者脂质反应性T细胞的功能。具体来说，我们将使用色谱法和质谱法来发现与每种CD1蛋白结合的新抗原，并确定它们识别的一般化学规则。此外，生物物理测量和蛋白质结晶将确定脂质抗原如何接触T细胞受体的强度和机制。利用人类细胞，我们将测量炎症小体和细胞因子在调节树突状细胞和组织中CD1蛋白表达方面的影响。最后，我们将使用新开发的细胞表面染色试剂来确定位于波士顿和南非夸祖鲁-纳塔尔省的人类患者队列中T细胞的关键细胞因子和抗菌效应功能。这些研究与美国国立卫生研究院的使命相关，因为它们关注的是患有自然疾病的人类受试者，因此结果可以转化为临床。鉴定启动CD1抗原呈递和T细胞活化所必需的分子，将使它们发展成为佐剂或疫苗。由于实验测量了cd1抗原-T细胞受体相互作用的一般功能，结果也将有助于了解相关T细胞介导的疾病如败血症、莱姆病、过敏性哮喘和动脉粥样硬化的发病机制。

DESCRIPTION (provided by applicant: M. tuberculosis remains a pathogen of global importance, currently infecting 1.6 billion people, killing 1.7 million annually. Successful human responses to infection depend critically on T cells, which were previously thought to be activated solely by peptide antigens bound to MHC proteins. However, CD1 proteins represent a newly discovered pathway for activation of T cells by mycobacteria and other pathogens. CD1 proteins are expressed in a highly regulated fashion on dendritic cells, where they capture mycobacterial lipid antigens for presentation to T cells. CD1 proteins are present in all mammals, so likely have an indispensable function in immune response. Although the basic functions of CD1d and NK T cells are becoming well understood, the natural functions of human CD1a, CD1b and CD1c proteins are not yet known. After discovering lipid antigens presented by CD1a (dideoxymycobactin), CD1b (glucose monomycolate) and CD1c (mannosyl phoshomycoketide), this renewal proposal uses a well developed model system to determine for the first time the general molecular mechanisms by which these antigens contact T cell receptors and the functions of lipid reactive T cells in human patients. Specifically, we will use chromatography and mass spectrometry to discover new antigens that bind to each type of CD1 protein and determine the general chemical rules of their recognition. Further, biophysical measurements and protein crystallization will determine the strength and mechanisms of how lipid antigens contact T cell receptors. Using human cells, we will measure the influence of the inflammasome and cytokines in regulating expression of CD1 proteins in dendritic cells and tissues. Last, we will use newly developed cell surface staining reagents to determine the key cytokines and anti-bacterial effector functions of T cells in cohorts of human patients located in Boston and KwaZulu-Natal, South Africa. These studies are relevant to the mission of the NIH because they focus on human subjects with natural diseases so that results can be translated into the clinic. Identification of the molecules necessary to initiate CD1 antigen presentation and T cell activation would allow their development as adjuvants or vaccines. Because experiments measure the general functions of the CD1-antigen-T cell receptor interaction, results would also inform understanding of the pathogenesis of related T cell-mediated diseases like sepsis, Lyme disease, allergic asthma and atherosclerosis.