Genetic and immunological dissection of coinhibitory crosstalks between human T cells and cancer cells

项目总结/摘要 该提案的目标是确定正交操作的新型共抑制检查点分子 目前针对癌症患者的检查点，如PD-1。尽管取得了前所未有的成功 检查点阻断免疫疗法作为针对多种类型癌症的治疗方法， 显著的个体间变异性仍然存在，范围从无反应到完全缓解， 全身转移性病变各种肿瘤内在参数，如肿瘤突变 新抗原负荷和错配修复途径缺陷，仅显示有限的预测性 有利的临床结果的力量。因此，与这些肿瘤内在因素互补， 似乎合理的假设，人类有迄今未知的共抑制机制正交 目前已知的免疫检查点，一小部分人与生殖系或体细胞 这些途径中的突变可能受益于由以下因素引发的异常强效的抗肿瘤免疫力： 检查点阻断免疫疗法。识别这种正交途径将显着 促进多种癌症患者的健康，例如， 帕博利珠单抗已经被指示。目前的项目旨在剖析人类基因 和免疫学基础的共抑制串扰之间的人T细胞和癌细胞的解决 两个具体目标。具体目标1是描述PD-L1/L2介导的细胞凋亡的分子机制。 不依赖于PD-1的T细胞活化的抑制。这一目标得到了初步观察的支持 来自遗传性完全PD-1缺乏症患者的原代和永生化T细胞， 以及PD-1阴性人T细胞系Jurkat和HuT 78，均对珠粒- 固定化PD-L1/L2。CD 83被确定为PD-L1介导的免疫抑制的候选者。 拟议的工作包括通过RNA测序和表面活性剂来寻找其他候选物。 通过RNA沉默和CRISPR引导的基因表达， 漂亮具体目标2是表征CD 83在人T细胞中的免疫调节功能。 以前的研究表明，CD 83可以作为免疫抑制受体和配体， 人T细胞，尽管其反受体、下游信号传导和抗肿瘤相关性 免疫性仍然很难得到。拟议的工作包括CD 83的生化表征 利用基因敲除和慢病毒在有或没有癌细胞共培养的人T细胞中的信号传导 拯救CD 83基因。拟议中的项目将有助于解开生物化学和免疫学基础 人类T细胞共抑制电路在癌细胞之间的串扰，也基本上支持 申请人的科学投资组合，并加快发展成为一个独立的调查员 开创了癌症免疫学和免疫疗法的人类遗传学。

PROJECT SUMMARY / ABSTRACT The goal of this proposal is to identify novel coinhibitory checkpoint molecules operating orthogonally to currently targeted checkpoints in cancer patients, such as PD-1. Despite the unprecedented success of checkpoint blockade immunotherapy as a therapeutic approach against multiple types of cancer, significant inter-individual variability remains, ranging from no response to complete remission of systemically metastasized lesions. Various tumor-intrinsic parameters, such as tumor mutational burden, neoantigen burden, and mismatch repair pathway deficiencies, only show limited predictive power for favorable clinical outcomes. Therefore, complementary to such tumor-intrinsic factors, it is plausible to hypothesize that humans have hitherto unknown coinhibitory mechanisms orthogonal to currently known immune checkpoints and that a minor fraction of humans with germline or somatic mutations in such pathways could benefit from exceptionally potent antitumor immunity triggered by checkpoint blockade immunotherapy. Identification of such orthogonal pathways would significantly enhance the health of patients with multiple types of cancer; for instance, the 15 types of cancer for which pembrolizumab has been indicated. The current project aims at dissecting the human genetic and immunological basis of coinhibitory crosstalk between human T cells and cancer cells by tackling the two specific aims. Specific Aim 1 is to delineate the molecular mechanisms of PD-L1/L2-mediated inhibition of T cell activation independent from PD-1. This aim is supported by preliminary observations that both primary and immortalized T cells from a patient with inherited complete PD-1 deficiency, as well as PD-1-negative human T cell lines Jurkat and HuT78, all responded to co-inhibition by bead- immobilized PD-L1/L2. CD83 was identified as a candidate for PD-L1-mediated immunosuppression. The proposed work includes searching for additional candidates through RNA sequencing and surface receptor profiling and functionally validating the candidates via RNA silencing and CRISPR-guided knockout. Specific Aim 2 is to characterize the immunoregulatory function of CD83 in human T cells. Previous studies suggest that CD83 can serve as both an immunosuppressive receptor and ligand for human T cells, although its counterreceptor(s), downstream signaling, and relevance to antitumor immunity remain mostly elusive. The proposed work includes biochemical characterization of CD83 signaling in human T cells with or without cancer cell coculture utilizing genetic knockout and lentiviral rescue of CD83 gene. The proposed project will help untangle the biochemical and immunological basis of human T cell coinhibitory circuits in the crosstalk between cancer cells and also substantially bolster the applicant's scientific portfolio and expedite the growth toward an independent investigator pioneering human genetics of cancer immunology and immunotherapy.