Elucidation of the role of 2 novel cross presentation genes

阐明 2 个新型交叉表达基因的作用

• 批准号: 9883698
• 负责人: KENNETH L ROCK
• 金额: $ 41.88万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9883698
• 关键词: AGFG1 gene; Antigen Presentation; Antigen Presentation Pathway; Antigens; Autoimmunity; Binding; CD8-Positive T-Lymphocytes; Cell surface; Cells; Complex; Cross Presentation; Data; Dendritic Cells; Development; Early Endosome; Endosomes; Ensure; Estrogen receptor positive; Genes; Genetic Screening; Goals; Grant; Guanosine Triphosphate Phosphohydrolases; I-antigen; Immune system; Immunity; Immunologic Surveillance; Immunotherapy; Infection; Investigation; Italy; Knowledge; Lead; Lysosomes; Malignant Neoplasms; Melanosomes; Pathway interactions; Peptides; Phagosomes; Phenotype; Process; Property; Proteins; Role; Structure; Surveys; T cell response; Testing; Tissues; Vaccines; Vesicle; Virus Diseases; base; gene discovery; genome-wide; late endosome; macrophage; novel; pathogen; public health relevance; recruit; response; tapasin; trafficking

 DESCRIPTION (provided by applicant): Dendritic cells (DCs) and macrophages are capable of acquiring and then displaying peptides from external antigens through a process called cross presentation. This process is the key mechanism that allows the immune system to recognize and then mobilize a CD8 T cell response to cancers, many viral infections and intracellular pathogens. Consequently, this pathway is important for immune surveillance and is an attractive target to enable vaccines to elicit CD8 T cell immunity. Given this, it is important to elucidate te mechanisms that allow DCs to carry out this critical function and this is the overall goal of this grant. To this end, we propose to characterize and elucidate the function of two key and previously unsuspected novel cross presentation genes that we discovered in an unbiased, genome-wide forward genetic screen. Our first Aim will elucidate the role of Rab39A in cross presentation. Very interestingly, while Rab39A is required for cross presentation but not conventional MHC I or MHC II presentation. Rab proteins are GTPases that control the formation, content, trafficking and ultimate fusion of vesicles in cells and thereby determine the composition of endocytic compartments. Our favored hypothesis is that Rab39A is functioning to help form a specialized XPT compartment in DCs by trafficking essential components of the XPT pathway. Furthermore, given their role in determining the composition of vesicles, Rabs and their recruited effectors serve as markers to identify and isolate unique endocytic compartments (e.g. early endosomes, late endosomes, lysosomes, melanosomes, etc.). In this context, and very interestingly, Rab39A is only present in a subset of phagosomes in DCs. Given this, we also hypothesize that Rab39A will mark the XPT compartment. The importance of these hypotheses is that Rab39A could solve the mystery as to how MHC I and/or other components from the ER get to phagosomes; clarify where XPT is carried out and its relationship to other pathways such as MHC II; and/or allow the characterization of the Rab39A+ compartment to identify novel components in the pathway. This Aim will test these hypotheses and more generally explore and elucidate the role of Rab39A in XPT. Our second Aim will elucidate the role of Loc547349 (Loc) in cross presentation. Our preliminary data show that this molecule is required for cross presentation but not classical MHC I or MHC II antigen presentation. Very interestingly, Loc is an MHC-encoded MHC I-like molecule of unknown function. This discovery is very intriguing because many of the key genes for MHC I and MHC II antigen presentation are encoded in the MHC locus. Moreover, there is a similar molecule, HLA-DM, that operates as a peptide editor in the MHC II pathway and for which up until now has not had a clear counterpart in the MHC I pathway, yet there is a theoretical need for such an activity for cross presentation. Our favored hypotheses are that Loc functions in cross presentation to help traffic MHC I molecules to endocytic compartments, stabilize them, and/or load them with peptides. The goal of this aim is to test this hypothesis as well as other potential functions and elucidate the role of Loc in cross presentation.

 描述（由应用程序提供）：树突状细胞（DCS）和巨噬细胞能够通过称为交叉表现的过程从外部抗原中获取并显示出辣椒。该过程是允许免疫系统识别并动员CD8 T细胞对癌症，许多病毒感染和细胞内病原体的反应的关键机制。因此，该途径对于免疫监视很重要，并且是使疫苗能够引起CD8 T细胞免疫力的有吸引力的靶标。鉴于此，重要的是阐明允许DC执行此关键功能的TE机制，这是该赠款的总体目标。为此，我们建议表征和阐明我们在公正的，全基因组的正向遗传筛选中发现的两个键和以前未指定的新型跨表现基因的功能。我们的第一个目标将阐明Rab39a在交叉演示中的作用。有趣的是，横介介绍需要RAB39A，但不是常规的MHC I或MHC II介绍。 Rab蛋白是控制细胞中蔬菜的形成，含量，运输和最终融合的GTPases，从而确定内吞区室的组成。我们首选的假设是，Rab39a通过运输XPT途径的运输基本要素来帮助在DC中形成专门的XPT隔室。此外，鉴于它们在确定蔬菜的组成中的作用，RAB及其招募的效果是识别和分离独特的内吞室的标志物（例如早期内体，晚期内体，溶酶体，黑素体等）。在这种情况下，有趣的是，Rab39a仅存在于DC中的吞噬体的子集中。鉴于此，我们还假设Rab39a将标志着XPT隔室。这些假设的重要性在于，Rab39a可以解决MHC I和/或其他急诊室中的其他成分如何进入吞噬体的神秘。 Clariife XPT的执行及其与MHC II等其他途径的关系；和/或允许Rab39a+隔室的表征识别途径中的新成分。该目标将检验这些假设，并更普遍地探索和阐明Rab39a在XPT中的作用。我们的第二个目标将阐明LOC547349（LOC）在交叉呈现中的作用。我们的初步数据表明，该分子是交叉呈现所必需的，但不是经典的MHC I或MHC II抗原表现。有趣的是，LOC是MHC编码的MHC I样分子，其功能未知。这一发现非常有趣，因为MHC I和MHC II抗原表现的许多关键基因都在MHC基因座中编码。此外，还有一个类似的分子HLA-DM，它是MHC II途径中的肽编辑器，并且到目前为止，在MHC I途径中还没有明确的对应物，但是理论上需要这种活动来进行交叉表现。我们首选的假设是，在交叉呈现中的LOC功能可以帮助交通MHC I分子到内吞室，稳定它们和/或用肽加载它们。该目标的目的是检验该假设以及其他潜在功能，并阐明LOC在交叉呈现中的作用。