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The novel role of the immunoproteasome subunit LMP7 in allo-immunity and T cell exhaustion

免疫蛋白酶体亚基 LMP7 在同种免疫和 T 细胞耗竭中的新作用

基本信息

批准号：
10057350
负责人：
Jamil Azzi
金额：
$ 37.38万
依托单位：
BRIGHAM AND WOMEN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-12-18 至 2022-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10057350
关键词：
Affinity Allografting Animal Model Antigen Presentation Antigens Apoptosis B-Lymphocytes Bone Marrow CD28 gene CD8-Positive T-Lymphocytes CD8B1 gene CTLA4-Ig Catalytic Domain Cell Death Cell physiology Cells Clinical Trials Clonal Deletion Clone Cells Collaborations Constitutional Data Defect Dendritic Cells Dendritic cell activation Exhibits Functional disorder Gene set enrichment analysis Genes Genetic Heart Transplantation Histocompatibility Human Immune Immune system Immunity Immunotherapy In Vitro Inflammatory Janus kinase Knock-out Liver Luciferases Major Histocompatibility Complex Malignant Neoplasms Molecular Mus Pathway interactions Peptide Hydrolases Phenotype Production Proteasome Inhibitor Protein Isoforms Protein Tyrosine Kinase Proteins Publishing Role Signal Transduction Skin Transplantation Stat5 protein System T-Cell Activation T-Lymphocyte Techniques Testing Therapeutic Thymus Gland Time Toxic effect Transplantation Tumor Necrosis Factor Ligand Superfamily Member 6 Ubiquitin Work allograft rejection allotransplant antibody-mediated rejection chronic infection clinical application conditional knockout cytokine design effector T cell exhaustion gang heart allograft humanized mouse immunoregulation in vivo inhibitor/antagonist islet isoimmunity mouse model multicatalytic endopeptidase complex novel novel strategies pre-clinical side effect transcriptome sequencing transplant model

项目摘要

Abstract T cell exhaustion is characterized by a progressive loss of inflammatory cytokines production followed by a functional and proliferation defect leading to apoptosis. While this phenomenon was studied recently in the context of allo-transplantation, it remains not well understood. Identifying and targeting key pathways involved in the induction of allo-immune T cell exhaustion will promote allograft acceptance. We recently showed that the immunoproteasome (i-20S) replaces the constitutional proteasome (c-20S) and becomes highly expressed in the human and murine T cells upon allo- activation making it an ideal target for allo-immunity. Hence, in collaboration with Dr. Gang Lin, we designed and synthesized a highly selective inhibitor of the LMP7 subunit of the i-20S that revealed an unexpected role for the LMP7 in T cell exhaustion through specific degradation of the JAK-STAT5 pathway and in promoting murine heart allograft survival across major histocompatibility complex (Esilida et al, PNAS, Dec 2016). While targeting c-20S is hindered by significant off target side effects, i-20S is an ideal target for allo-immunity as it's enriched in immunocytes upon activation. Our hypothesis is that during alloimmune T cell activation, the immunoproteasome subunit LMP7 is upregulated, promoting degradation of phosphorylated STAT5 (pSTAT5) through its protease activity to protect the antigen-reacting effector T cells from immune regulation and exhaustion. Hence, inhibiting the immunoproteasome subunit LMP7 increases pSTAT5, induces T cell exhaustion and Fas/FasL apoptosis leading to clonal deletion, and promotes allograft survival without toxic off target effects. To test our hypothesis, we will use selective inhibitors generated in collaboration with Dr. Gang Lin in an antigen specific transplant model (OTI, OTII, OVA) and will track the allo-reactive T cell clones using a novel non-invasive luciferase technique in vivo. We also generated knockouts of LMP7 on the OTI and OTII backgrounds and a conditional knockout of LMP7 selectively in CD4 and CD8 T cells. We will use molecular techniques to identify how the LMP7 degrade STAT5 and if STAT5 activation leads to T cell apoptosis and clonal deletion. Finally, to generate preclinical data, we will test our therapeutic strategy on the human immune system using a humanized mouse model transplanted with human islets.

摘要 T细胞衰竭的特征是炎性细胞因子的进行性丢失产生，随后是功能和增殖缺陷，导致细胞凋亡。虽然这最近在同种异体移植的背景下研究了这一现象，但仍不清楚明白识别和靶向诱导同种免疫T细胞的关键途径疲劳将促进同种异体移植物的接受。我们最近发现，免疫蛋白酶体（i-20 S）取代了宪法的蛋白酶体（c-20 S），并在同种异体移植后在人和鼠T细胞中高度表达。活化使其成为同种免疫的理想靶点。因此，在与林刚博士的合作中，我们设计并合成了一种高度选择性的i-20 S LMP 7亚基抑制剂，揭示了LMP 7在T细胞耗竭中的意想不到的作用，通过特异性降解LMP 7， JAK-STAT 5通路和促进小鼠心脏移植物存活的主要机制组织相容性复合物（Esilida et al，PNAS，Dec 2016）。虽然瞄准c-20 S受到阻碍，显著的脱靶副作用，i-20 S是同种免疫的理想靶点，因为它富含免疫细胞激活。我们的假设是，在同种免疫T细胞活化过程中，免疫蛋白酶体 LMP 7亚基被上调，通过以下途径促进磷酸化STAT 5（pSTAT 5）的降解：其保护抗原反应效应T细胞免受免疫调节的蛋白酶活性，疲惫不堪因此，抑制免疫蛋白酶体亚基LMP 7增加pSTAT 5，诱导 T细胞耗竭和Fas/FasL凋亡导致克隆性缺失，促进同种异体移植没有毒性脱靶效应的生存。为了验证我们的假设，我们将使用与Dr. 林刚在抗原特异性移植模型（OTI、OTII、OVA）中将追踪同种异体反应性使用一种新的非侵入性荧光素酶体内技术的T细胞克隆。我们还产生在OTI和OTII背景上敲除LMP 7和条件性敲除LMP 7 选择性地在CD 4和CD 8 T细胞中。我们将使用分子技术来鉴定LMP 7 如果STAT 5的活化导致T细胞凋亡和克隆缺失，最后为生成临床前数据，我们将在人类免疫系统上测试我们的治疗策略使用移植了人类胰岛的人源化小鼠模型。