Immunological impact of Tetherin retrovirus restriction

Tetherin 逆转录病毒限制的免疫影响

基本信息

批准号：
8916014
负责人：
Mario Luis Santiago
金额：
$ 19.44万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-25 至 2016-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8916014
关键词：
Acute Adjuvant Adult Alleles Anti-Retroviral Agents Antigen Presentation Antigen-Presenting Cells Back Backcrossings Biology Bypass CD4 Positive T Lymphocytes CD8B1 gene Cell Culture Techniques Cell surface Cells Cellular Immunity Conflict (Psychology)Controlled Study Cross Presentation Data Defect Dependence Development Endocytosis Friends Genes Genetic Genetic Epistasis Genotype HIV vaccine HIV-1 Health Histocompatibility Antigens Class II Human Hybridomas Immune system Immunity Immunobiology Immunocompetent Immunologic Factors Immunologics Immunology Immunotherapeutic agent Immunotherapy In Vitro Inbred Strains Mice Infection Investigation Knock-out Knockout Mice Link Major Histocompatibility Complex Mediating Modeling Mouse Strains Mus Mutation N-terminal Pathogenesis Peptides Proteins Publishing Recycling Reporting Research Resistance Retroviridae Retroviridae Infections Role Shapes Single Nucleotide Polymorphism Site Sorting - Cell Movement Surface System T cell response T-Lymphocyte Testing Toll-like receptors Translations Vaccines Viral Virion Virus Replication Work adaptive immunity arm cell mediated immune response design high risk improved in vivo inhibitor/antagonist insight interest mouse model neutralizing antibody pandemic disease pathogen resistance gene vpu Protein

项目摘要

DESCRIPTION (provided by applicant): The innate arm of the immune system can critically shape the adaptive immune response against pathogens. Thus, innate sensing mechanisms have been studied extensively for rational adjuvant design. In contrast, much less is known about the immunological impact of 'restriction factor' genes that could directly inhibit virus replication. Tetherin is the protein counteracted by Vpu of pandemic HIV-1 to promote virion release. In the absence of Vpu, Tetherin 'tethers' virions on the cell surface. Subsequently, these tethered virions are brought back into the infected cell through Tetherin-mediated endocytosis. The immunobiology of Tetherin remains unknown, and in vitro studies raised controversies on whether it acts as a retrovirus restriction factor. Thus, in vivo studies that isolate the gene for controlled study may help advance insights and resolve discrepancies on Tetherin function. In addition, investigating the biology of Tetherin in vivo may benefit from disrupting its mysterious endocytic function. Recently, we identified an inbred mouse strain that harbored a Tetherin single nucleotide polymorphism (SNP) that resulted in an endocytosis defect (Barrett et al. PLOS Pathogens 2012). In published and unpublished genetic backcrossing studies, we discovered that the impact of this Tetherin endocytosis SNP on Friend retrovirus (FV) infection is dependent on the Major Histocompatibility Complex (MHC) locus. Moreover, MHC Class II+ antigen-presenting cells (APCs) expressing Tetherin stimulated an FV- specific CD4+ T cell hybridoma to a greater extent than Tetherin-deficient APCs. Thus, Tetherin-mediated virion endocytosis in APCs may increase the viral peptide pool for MHC Class II presentation and augment the retrovirus-specific CD4+ T cell response. We propose to test this hypothesis using two complementary systems. In Specific Aim 1, we will evaluate the ability of APCs expressing wild-type, knock- out and endocytosis-defective Tetherin to stimulate CD4+ T cells in the FV infection model. Since Tetherin may also impact cross-presentation to MHC Class I, we will also investigate the CD8+ T cell response. In Specific Aim 2, we will test if enabling Tetherin activity through a disruptive Vpu mutation would render the HIV-1 infected target cells more susceptible to the cytolytic and suppressive effects of HIV-1 specific CD4+ T cell clones in vitro. Concordant results from the proposed in vivo immunologic studies and HIV-1 in vitro studies may provide insights in harnessing Tetherin biology for retroviral immunotherapeutics and T-cell vaccines.

描述（由申请人提供）：免疫系统的先天臂可以关键地塑造针对病原体的适应性免疫反应。因此，为了合理的佐剂设计，先天传感机制已被广泛研究。相比之下，人们对可直接抑制病毒复制的“限制因子”基因的免疫影响知之甚少。 Tetherin 是一种被流行性 HIV-1 的 Vpu 抵消的蛋白质，可促进病毒颗粒释放。在没有 Vpu 的情况下，Tetherin 将病毒粒子“束缚”在细胞表面。随后，这些束缚的病毒粒子通过束缚蛋白介导的内吞作用被带回受感染的细胞中。 Tetherin 的免疫生物学仍然未知，体外研究对其是否作为逆转录病毒限制因子产生了争议。因此，分离基因进行对照研究的体内研究可能有助于加深对 Tetherin 功能的了解并解决差异。此外，研究 Tetherin 的体内生物学可能会受益于破坏其神秘的内吞功能。最近，我们鉴定出一种近交小鼠品系，其含有导致内吞作用缺陷的 Tetherin 单核苷酸多态性 (SNP)（Barrett 等人。PLOS Pathogens 2012）。在已发表和未发表的遗传回交研究中，我们发现 Tetherin 内吞 SNP 对 Friend 逆转录病毒 (FV) 感染的影响取决于主要组织相容性复合体 (MHC) 位点。此外，表达 Tetherin 的 MHC II+ 类抗原呈递细胞 (APC) 比 Tetherin 缺陷的 APC 更大程度地刺激 FV 特异性 CD4+ T 细胞杂交瘤。因此，APC 中 Tetherin 介导的病毒粒子内吞作用可能会增加 MHC II 类呈递的病毒肽库，并增强逆转录病毒特异性 CD4+ T 细胞反应。我们建议使用两个互补的系统来检验这个假设。在具体目标 1 中，我们将评估表达野生型、敲除型和内吞作用缺陷型 Tetherin 的 APC 在 FV 感染模型中刺激 CD4+ T 细胞的能力。由于 Tetherin 也可能影响 MHC I 类的交叉呈递，因此我们还将研究 CD8+ T 细胞反应。在具体目标 2 中，我们将测试通过破坏性 Vpu 突变启用 Tetherin 活性是否会使 HIV-1 感染的靶细胞在体外更容易受到 HIV-1 特异性 CD4+ T 细胞克隆的细胞溶解和抑制作用。拟议的体内免疫学研究和 HIV-1 体外研究的一致结果可能为利用 Tetherin 生物学进行逆转录病毒免疫治疗和 T 细胞疫苗提供见解。