Learning from attenuated CMV how to broaden HIV-specific T cell responses

从减毒 CMV 中学习如何扩大 HIV 特异性 T 细胞反应

• 批准号: 8895261
• 负责人: Sylvie Le Gall
• 金额: $ 54.88万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8895261
• 关键词: Affect; Antigen-Presenting Cells; Antigens; Area; Attenuated; Binding; Biochemical; Biological Assay; Bypass; CD4 Positive T Lymphocytes; CD8B1 gene; Cell membrane; Cells; Cellular Tropism; Computer Analysis; Cross Presentation; Cytomegalovirus; Cytomegalovirus Infections; Cytosol; Dendritic Cells; Development; Disease; Endoplasmic Reticulum; Epitopes; Event; Fibroblasts; Frequencies; Gagging; HIV; HIV Antigens; HIV Infections; HIV vaccine; Health; Human; Immune response; Immunologic Deficiency Syndromes; In Vitro; Infection; Kinetics; Knowledge; Lead; Learning; Length; Life; Lysosomes; MHC binding peptide; Macaca; Macaca mulatta; Mass Spectrum Analysis; Measures; Memory; Methodology; Mus; Outcome; Pattern; Peptide Hydrolases; Peptide/MHC Complex; Peptides; Play; Process; Production; Proteins; Role; Route; SIV; Shapes; Source; System; T cell response; T-Lymphocyte; Testing; Time; Vaccinated; Vaccination; Vaccine Design; Vaccines; Variant; Viral Proteins; Virion; Virus; Walkers; antigen processing; base; cell type; design; in vivo; lymph nodes; multidisciplinary; nanoparticle; pathogen; protein degradation; public health relevance; response; trafficking; vector

DESCRIPTION (provided by applicant): Vaccination of Rhesus Macaques with an attenuated CMV virus carrying SIV proteins (RhCMV-SIV) led to an unprecedented durable control and clearance of SIV in 50% of vaccinated Macaques, a positive outcome predicted by the magnitude of CD8 T cell responses during vaccination and effector T cell responses in lymph nodes after infection. RhCMV-SIV vaccination broke natural immunodominance and led to broad CD4 T cells and CD8 responses covering many areas of SIV antigens. Surprisingly most SIV-specific CD8 T cells responses elicited by this vaccine were restricted by MHC-II. Whereas the results are among the most promising to date in the HIV vaccine field the use of CMV vectors for HIV vaccination raise health concerns. The first event required to prime T cell responses is the presentation of MHC-I- and MHC-II-bound peptides by antigen presenting cells (APC) to T cells. These peptides come from the multistep intracellular degradation of proteins by the antigen processing machinery. Considering the capacity of WT CMV to alter MHC-peptide presentation we propose that attenuated CMV expressing HIV proteins (HCMV-HIV) creates unique conditions for processing and presentation of HIV epitopes leading to broad unconventional T cell responses, and that these conditions can be replicated without the use of CMV by transiently manipulating the antigen processing machinery during the delivery of the immunogen in APC. To unveil these mechanisms of protein degradation and epitope presentation in the presence of attenuated HCMV-HIV we have developed throughput assays to measure antigen processing activities in primary cells, mass spectrometry-based assays to follow the degradation of proteins or virions in the two cellular compartments where the virus may enter: cytosol and endo-lysosomes, and methodologies to identify intracellular epitope precursors and MHC-bound peptides in HIV-infected cells. We showed that variations in the levels of peptidase activities among cell subsets play a critical role in shaping the lengths and kinetics of peptides produced for epitope presentation. Using a combination of biochemical, computational, in vitro and in vivo immunological approaches we propose to 1) Determine the effect of attenuated HCMV-HIV on HIV protein degradation in target cell subsets, 2) Assess epitope presentation and priming of T cell responses in the context of attenuated HCMV-HIV infection, and 3) Design and test a CMV-free antigen delivery system leading to broad HIV-specific T cell responses. This project builds on a multidisciplinary collaborative approach between the PI, Dr Heckerman for computational analysis of HIV degradation products, Dr Picker for HCMV expertise in CMV, Dr Moris for in vitro priming assays of HIV-specific T cell responses, Dr Walker for HIV-specific T cells, Dr Tager for humanized mice and Dr Irvine for the development of nanoparticles for antigen delivery.

描述（由申请人提供）：鼠尾草猕猴的疫苗接种，带有衰减的CMV病毒携带SIV蛋白（RHCMV-SIV）导致了50％的接种猕猴中SIV的前所未有的耐用控制和清除率，这是CD8 T细胞反应量的阳性结果，在疫苗响应的幅度中预测到了Pycecation and pycecation and pressect and the the vers and pressect and pressect and pressect and presse and te rym t y rym t rectect and te rym t。 RHCMV-SIV疫苗接种破坏了自然免疫官方，并导致涵盖SIV抗原许多区域的CD4 T细胞和CD8反应。出乎意料的是，大多数SIV特异性CD8 T细胞反应由该疫苗引起的MHC-II限制。尽管结果是迄今为止HIV疫苗领域最有前途的结果之一，但使用CMV载体用于HIV疫苗接种引起了健康问题。促进T细胞反应所需的第一个事件是抗原呈递细胞（APC）向T细胞呈现MHC-I-和MHC-II结合的肽。这些肽来自抗原加工机械的多阶段蛋白质细胞内降解。考虑到WT CMV改变MHC肽表现的能力，我们提出，我们提出的是减弱表达HIV蛋白（HCMV-HIV）的CMV会为处理和表现呈现HIV表现的独特条件，从而导致广泛的非常常见的T细胞反应，并且可以通过临时处理CMV的使用而无需复制这些条件，而无需通过触发CMV的启动，使静止的静止范围固定在机构中，使得静止范围内的静止。 APC。 To unveil these mechanisms of protein degradation and epitope presentation in the presence of attenuated HCMV-HIV we have developed throughput assays to measure antigen processing activities in primary cells, mass spectrometry-based assays to follow the degradation of proteins or virions in the two cellular compartments where the virus may enter: cytosol and endo-lysosomes, and methodologies to identify intracellular epitope HIV感染细胞中的前体和MHC结合的肽。我们表明，细胞子集中肽酶活性水平的变化在塑造用于表位表现的肽的长度和动力学方面起着关键作用。使用生物化学，计算，体外和体内免疫学方法的结合，我们建议1）确定靶细胞子集中衰减的HCMV-HIV对HIV蛋白降解的影响，2）评估表位表现和启动HCMV-HIV感染和HCMV-HIV Invection and Testivic testivic and Testivic and Testivic to and hiv testivic and Testivic testivic and Testivic testivic to and hiv frifice tes hiv frife and hiv frife and Testivic and Testivic and Testivic and Testive tes tess Design a cmv frife and cmv frife T细胞反应。 This project builds on a multidisciplinary collaborative approach between the PI, Dr Heckerman for computational analysis of HIV degradation products, Dr Picker for HCMV expertise in CMV, Dr Moris for in vitro priming assays of HIV-specific T cell responses, Dr Walker for HIV-specific T cells, Dr Tager for humanized mice and Dr Irvine for the development of nanoparticles for antigen delivery.