Synthetic rescue of antigen-driven T cells and alloimmunity

抗原驱动T细胞和同种免疫的综合拯救

基本信息

批准号：
10543445
负责人：
Jonathan A Soboloff
金额：
$ 63.76万
依托单位：
TEMPLE UNIV OF THE COMMONWEALTH
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-12 至 2023-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10543445
关键词：
Allogenic Antigens Artemisinins Autoimmune Diseases Automobile Driving CD8B1 gene Ca(2+)-Transporting ATPase Calcineurin inhibitor Cell Death Cell Differentiation process Cell Survival Cell membrane Cellular Assay Cellular biology Clinical Cyclosporine Cytosol DNA Synthesis Inhibitors Development Differentiation Antigens Disease Endoplasmic Reticulum Epigenetic Process Gatekeeping Generations Goals Homeostasis Human ITPR1 gene Immunity Immunotherapy Impairment Inbred BALB C Mice Inflammatory Investigation Libraries Ligation Malaria Malignant Neoplasms Mediating Methods Mitochondria Molecular Mus Na(+)-K(+)-Exchanging ATPase Natural Compound Outcome Pathogenesis Pathway interactions Patients Production Proteins Pump Reaction Regimen Repression Role STIM1 gene Signal Transduction T cell response T memory cell T-Cell Activation T-Cell Proliferation T-Cell Receptor T-Lymphocyte Tacrolimus Testing Therapeutic Toxic effect Translating Water artesunate calcium uniporter chronic infection disorder prevention effector T cell experimental study graft vs host disease graft vs leukemia effect histone methyltransferase improved insight interest isoimmunity mitochondrial metabolism novel novel strategies nuclear factors of activated T-cells pharmacologic preservation prophylactic response sensor tissue injury uptake

项目摘要

During graft-versus-host disease (GVHD), donor T cells require the histone methyltransferase Ezh2 for producing and sustaining effector T cells that mediate host tissue injury. We recently established that Ezh2 serves as a molecular gatekeeper for the generation of CD8 memory T cell precursors in GVHD, critical for the production of effector T cells in response to persistent antigen (Nat Commun 2017). However, our efforts to develop novel approaches to selectively target alloreactive effector T cells has been limited by the lack of understanding of why Ezh2 loss causes cell death of antigen-activated T cells. Stromal interaction molecule (Stim) proteins, Stim1 and Stim2, are crucial dynamic endoplasmic reticulum (ER) Ca2+ sensors and modulators of Ca2+ signals. Upon T cell receptor (TCR) ligation, Stim1 activation causes its translocation towards the plasma membrane, where it activates the Ca2+ channel Orai1, facilitating Ca2+ entry and driving T cell activation. Conditional Stim1 deletion inhibits GVHD in mice due to impaired effector differentiation. Remarkably, Stim1 deletion rescues antigen-activated Ezh2-null T cells, leading to restored production of alloreactive effector T cells in mice and severe GVHD. Therefore, we hypothesize that: A) Ezh2 and Stim1 operate coordinately to regulate the viability and function of antigen-driven T cells; and B) Ezh2/Stim1- regulated molecular pathway(s) are crucial for controlling alloreactive T cell-mediated GVHD. We further establish that the role of Stim1 in Ezh2-mediated cell death is to drive mitochondrial Ca2+ (mitoCa2+) overload since conditional deletion of the mitochondrial calcium uniporter (MCU), leads to rescue of antigen-activated Ezh2-null T cells. To establish the therapeutic potential of these findings, we performed a preliminary screen with an 800 compound library, finding 36 compounds that block T cell proliferation. Amongst them was artesunate (ART), a water-soluble derivative of artemisinin clinically approved for the treatment of malaria and known to target the Sarco/Endoplasmic Reticulum Ca2+ ATPase (SERCA), which pumps Ca2+ from the cytosol to the ER lumen. SERCA inhibition leads to Stim1/Orai1 activation and mitoCa2+ uptake. Preliminary investigations show that ART treatment reduces GVHD in BALB/C mice receiving allogeneic C57BL/6 T cells. Considered collectively, these findings suggest that Ezh2 regulates antigen-specific effector T cell survival through modulation cytosolic Ca2+ entry, thereby limiting mitochondrial Ca2+ loading and protecting against cell death. This hypothesis will be tested through three specific aims. In Aim-1, we will define the mechanisms that regulate the survival and differentiation of antigen-driven Ezh2/Stim1-null T cells. Aim-2 will determine the molecular mechanisms by which Ezh2 deficiency dysregulates cytosolic and mitochondria Ca2+ uptake in activated T cells. Finally, Aim-3 will examine the beneficial effect of enhancing T cell Ca2+ load to modulate GVHD and GVL activity in mice. Completion of these experiments will provide novel insights into T cell biology, T cell-mediated inflammatory disorders such as GVHD and autoimmune diseases, and lead to development of novel methods for improving the efficacy of immunotherapy for chronic infections and cancer.

在移植物抗宿主病（GVHD）期间，供体T细胞需要组蛋白甲基转移酶EZH2用于产生介导宿主组织的效应效应T细胞受伤。我们最近确定EZH2是生成的分子守门人 GVHD中的CD8记忆T细胞前体，对于响应效应T细胞的产生至关重要持续的抗原（Nat Commun 2017）。但是，我们为开发新颖方法的努力有选择地靶向同种反应性效应t细胞受到了缺乏的限制了解为什么EZH2损失会导致抗原激活T细胞的细胞死亡。基质相互作用分子（刺激）蛋白，imt1和stim2是至关重要的动态内质网（ER） Ca2+传感器和CA2+信号的调节器。在T细胞受体（TCR）连接时， Stim1激活导致其易位向质膜，在该膜中激活 Ca2+通道ORAI1，促进Ca2+进入和驱动T细胞激活。有条件的STIM1 由于效应子分化受损，缺失抑制小鼠的GVHD。值得注意的是 STIM1删除营救了抗原激活的EZH2-NULL T细胞，导致恢复在小鼠和严重GVHD中产生同种异体效应T细胞。因此，我们假设那就是：a）ezh2和stim1协调运行以调节抗原驱动的T细胞； b）EZH2/STIM1调控的分子途径（S）对于控制同种异体T细胞介导的GVHD。我们进一步确定imt1的作用在EZH2介导的细胞死亡中，是为了驱动线粒体Ca2+（Mitoca2+）超负荷线粒体钙Uniporter（MCU）的缺失导致抗原激活 EZH2-NULL T细胞。为了确定这些发现的治疗潜力，我们进行了带有800复合库的初步屏幕，找到36种阻断T细胞的化合物增殖。其中有敏捷（Art），是Artemisinin的水溶性衍生物临床批准用于治疗疟疾，并已知靶向Sarco/内质。网状Ca2+ ATPase（SERCA），该速度从细胞质泵送至ER管腔。 Serca 抑制作用会导致stim1/orai1激活和MitoCA2+摄取。初步的调查表明，ART治疗减少了接受同种异体C57BL/6 T的BALB/C小鼠中的GVHD 细胞。这些发现集体考虑，表明EZH2调节抗原特异性效应子T细胞通过调制胞质Ca2+进入，从而限制线粒体Ca2+负载并防止细胞死亡。该假设将进行检验通过三个特定目标。在AIM-1中，我们将定义调节生存的机制和抗原驱动的EZH2/stim1-null T细胞的分化。 AIM-2将确定 EZH2缺乏失调的胞质和线粒体的分子机制激活的T细胞中的Ca2+摄取。最后，AIM-3将研究增强的有益效果 T细胞Ca2+负载可调节小鼠的GVHD和GVL活性。这些实验的完成将提供有关T细胞生物学的新见解，T细胞介导的炎症性疾病，例如 GVHD和自身免疫性疾病，并导致开发用于改善的新方法免疫疗法对慢性感染和癌症的功效。