Defining cellular and molecular mechanisms underlying cancer immunotherapy-induced autoinflammatory syndromes.

Checkpointinhibitors (cpi) aretransformingtreatmentofseveralsolidtumours(1)。Therationalefortheirmechanismcentreson breakingimmunetolerancetotumourantigenstoenableeffectorTcellstokilltumourcells。这是通过抑制免疫检查点分子（如ctla -4和pd -1）来实现的，onT细胞克服了免疫抑制(2)。这些治疗的限制导致一系列自身炎症综合征的出现，这些综合征统称为免疫相关不良事件（IRAEs），反映了一系列自身免疫性疾病(3)。irae可以影响任何器官或组织，但最常见的目标是皮肤、胃肠道、内分泌和肌肉骨骼系统，它们可能是致命的（4-5），发病率很高(例如：在盖伊和圣托马斯NHS基金会信托（GSTFT）癌症中心接受CPI治疗的患者队列（N=175）中，针对多个器官的任何级别irae的发生率为65%。IRAEs表现了几种自身免疫性疾病，这表明IRAEs和这些疾病可能有共同的致病机制，导致耐受性的丧失(6)。研究可能因此在自身免疫性疾病的病因学上有机会性发现。此外，一些研究已将IRAE发生率与接受CPI治疗的癌症患者生存结果的改善联系起来（7-8），这表明IRAE与抗癌免疫之间存在机制联系。然而，目前尚不清楚irae的细胞和分子驱动因素。治疗IRAEs的指导方针是暂停CPI治疗直至消退(4)，因此IRAE治疗除了对患者自身构成风险外，还有可能阻碍CPI的疗效。不良免疫反应病理生物学（PAIR）研究是一项积极的前瞻性队列研究，收集接受CPIs治疗几种癌症类型的GSTFT患者的纵向血液样本，用于研究IRAEs的机制。拟议的项目旨在探测PAIR研究样本，以阐明CPIs诱导的外周血免疫细胞群的最早表型变化，并确定在其最早可检测阶段检测这些变化是否可以识别IRAE风险的生物标志物。因此，我们的目标是解决围绕IRAEs的关键科学和临床需求。我们实验室的初步数据表明，几种可溶性炎症介质的血清水平可能表明IRAE发展的可能性，并且大量细胞术可用于跟踪PAIR研究受试者系列血液样本中的免疫细胞表型变化，以研究cpi诱导的变化。这些数据支持我们提出的实验方法和假设（见下文）。我的实验目标是：1。深度表型外周免疫细胞群存在于pair患者pbmcs样本中，使用大量细胞术和无监督数据分析技术来确定(a)早期cpi诱导的表型变化和(b)经历不同级别fires的患者基线免疫细胞表型的差异。使用流式细胞术验证鉴定的细胞群。从功能上描述可能驱动病毒的效应人群。测试在体外对基线PBMC样本进行CPI治疗是否可以诱导体内观察到的细胞和分子反应，以及这些反应是否在进入发展阶段的患者样本中得到增强。

Checkpointinhibitors(CPIs)aretransformingtreatmentofseveralsolidtumours(1).Therationalefortheirmechanismcentreson breakingimmunetolerancetotumourantigenstoenableeffectorTcellstokilltumourcells.Thisisachievedbyinhibitingimmune checkpointmolecules(suchasCTLA-4andPD-1)onT cellstoovercomeimmunesuppression(2).Alimitation ofthesetherapiesis the emergence of a range of autoinflammatory syndromes, collectively termed immune-related adverse events (IRAEs), that phenocopy a range of autoimmune diseases (3). IRAEs can affect any organ or tissue but most frequently target skin, gastrointestinal,endocrineandmusculoskeletalsystems.Theycanbesevereorevenfatal(4-5)andincidenceishigh(e.g.incidence of any grade IRAEs targeting multiple organs in a cohort of patients (N=175) receiving CPI therapy in the Cancer Centre at Guy's and St Thomas' NHS Foundation Trust (GSTFT) is65%).IRAEs phenocopy several autoimmune diseases suggesting IRAEs and these diseases may share pathogenic mechanisms resulting inlossoftolerance(6).StudyofIRAEsmaythusyieldopportunisticdiscoveriesintheaetiologiesofautoimmunediseases.Further, some studies have associated IRAE incidence with improved survival outcomes for cancer patients receiving CPI therapy (7-8), suggesting mechanistic links between IRAEs and anti-cancer immunity. However, the cellular and molecular drivers of IRAEs are currently undetermined. Guidance for treatment of IRAEs is suspension of CPI therapy until resolution (4) hence IRAE treatment has the potential to hinder CPI efficacy, in addition to presenting a risk to patientsthemselves.The Pathobiology of Adverse Immune Reactions (PAIR) Study is an active prospective cohort study collecting longitudinal blood samples from GSTFT patients receiving CPIs for treatment of several cancer types for mechanistic studies of IRAEs. The proposed project seeks to probe PAIR Study samples to elucidate the earliest phenotypic changes in peripheral immune cell populations induced by CPIs, and to determine whether detection of these changes at their earliest detectable stage could allow for identification of biomarkers of IRAE risk. We thus aim to address both critical scientific and clinical needs surrounding IRAEs. Preliminary data from our lab suggest serum levels of several soluble inflammatory mediators may indicate likelihood of IRAE development, and that mass cytometry can be used to track immune cell phenotypic changes across serial bloodsamples of PAIR Study subjects to study CPI-induced changes. These data support our proposed experimental approach and hypotheses (see below).My experimental goals are to:1.DeeplyphenotypeperipheralimmunecellpopulationspresentinPAIRpatientPBMCsamplesusingmasscytometryalongside unsupervised data analysis techniques to identify (a) the earliest CPI-induced phenotypic changes and (b) differences in the baseline immune cell phenotypes of patients experiencing different grades ofIRAEs.2.Validate identified cell populations using flowcytometry.3.Functionally characterise effector populations that may be drivingIRAEs.4.Test whether CPI treatment of baseline PBMC samples in vitro can induce cellular and molecular responses observed in vivo, and whether these responses are augmented in samples from patients who proceed to developIRAEs.