Plasticity of Innate Lymphoid Cells: Mechanisms and Biological Impact

项目总结 免疫细胞的功能可塑性对于微调它们对不同刺激的反应是必不可少的。虽然 可塑性可能会导致不必要的副作用，它也可能被利用来引导免疫反应 期望的结果。先天淋巴样细胞(ILC)是一种缺乏抗原特异性受体的淋巴细胞，可产生 免疫反应早期阶段的细胞因子。基于转录因子和细胞因子的特定网络 ILC分为三个亚群：T-bet+ILc1释放干扰素-γ，GATA3+ILC2分泌IL-5和IL-13； RoRγt+ILC3产生IL-22和IL-17。最近的研究表明，ILC在功能上是可塑性的， 受微环境变化的影响，这提出了突出的问题：1)而人类的ILC 在体外功能可塑性，它们在体内是否同样灵活？如果是，涉及什么机制？2)在体内 在小鼠身上的命运图谱研究已经证明了ILC在稳定状态下的可塑性； 疾病模型中ILC的可塑性？3)什么表观遗传回路控制ILC对疾病模型中的波动的反应 微环境？我们将通过三个目标来解决这些问题。目标1展示了第一个演示 人类扁桃体中同时具有ILC3和ILc1特征的过渡性ILC亚群，这是ILC3→ILc1的证据 体内转化。我们还提供了数据，表明IKZF3编码的转录因子Aiolos是必需的 为了过渡。我们将测试Aiolos与其他转录因子合作驱动人类 使用体外和体内方法进行ILC3ILC1ILc1的转化。我们将进行ILC3→ILC1染色质研究 转换以进一步定义控制ILC3/ILC1可塑性的调节电路和转录因子。克隆性 将使用过渡ILC子集的分析来证实它们的同质性和发展性 弹道。在目标2中，我们建议精确地描述人类ILC3/ILC1过渡性群体 在肠道中，通过质量细胞仪和scRNAseq，因为它们不像扁桃体那样被清楚地定义。此外，我们 建议进行活体小鼠研究，以确定改变肠道微环境的疾病是否会导致 ILC3/1可塑性，进而可塑性是否影响胃肠道感染时的免疫反应 IBD。这些实验将在RoRγt报告基因小鼠和重组的ILC3缺陷小鼠身上进行 ILC3或前ILC3。在目标3中，我们将测试假设，在导致1型和3型的疾病中 极化细胞因子，肠道和皮肤中的ILC2转化为ILC1/3。我们将在体内使用 报告小鼠并测试塑料ILC2在感染、IBD和过继皮肤炎模型中的影响 传递实验。我们还将在染色质研究中定义控制ILC2可塑性的调节元件。 我们希望，我们在国际法委员会领域的专门知识和领导能力将产生对国际法委员会职能适应的综合看法。 在豁免权方面。

PROJECT SUMMARY Functional plasticity of immune cells is essential to fine-tune their responses to disparate stimuli. Although plasticity may cause unwanted side effects, it may also be harnessed to steer immune responses towards desired outcomes. Innate lymphoid cells (ILC) are lymphocytes devoid of antigen-specific receptors that produce cytokines at early stages of immune responses. Based on specific networks of transcription factors and cytokine profiles, ILC are subdivided into three subsets: T-bet+ ILC1 release IFN-γ; GATA3+ ILC2 secrete IL-5 and IL-13; RORγt+ ILC3 produce IL-22 and IL-17. Recent studies showed that ILC are functionally plastic and heavily influenced by changes in the microenvironment, which raises outstanding questions: 1) While human ILC are functionally plastic in vitro, are they equally flexible in vivo and, if so, what mechanisms are involved? 2) In vivo fate mapping studies in mice have documented ILC plasticity in steady state; what is the extent and impact of ILC plasticity in disease models? 3) What epigenetic circuits control ILC responses to fluctuations in the microenviroment? We will address these questions in three aims. Aim 1 presents the first demonstration of transitional ILC subsets in human tonsils with features of both ILC3 and ILC1, which is evidence for ILC3→ILC1 conversion in vivo. We also present data indicating that the IKZF3-encoded transcription factor Aiolos is required for transition. We will test the hypothesis that Aiolos cooperates with other transcription factors to drive human ILC3→ILC1 conversion, using in vitro and in vivo approaches. We will perform chromatin studies of ILC3→ILC1 conversion to further define regulatory circuits and transcription factors that govern ILC3/ILC1 plasticity. Clonal analyses of transitional ILC subsets will be employed to corroborate their homogeneity and developmental trajectory. In Aim 2, we propose to precisely characterize ILC3/ILC1 transitional populations in the human intestine by mass cytometry and scRNAseq, as they are not as clearly defined as those in tonsils. Moreover, we propose in vivo mouse studies to determine whether diseases that alter intestinal microenvironment induce ILC3/1 plasticity and, in turn, whether plasticity impacts immune responses during gastrointestinal infections and IBD. These experiments will be carried out in Rorγt-reporter mice and in ILC3-deficient mice reconstituted with either ILC3 or ex-ILC3. In Aim 3, we will test the hypothesis that in diseases that induce type 1 and type 3 polarizing cytokines, ILC2 in the gut and skin convert into ILC1/3. We will track ILC2 plasticity in vivo using reporter mice and test the impact of plastic ILC2 in models of infections, IBD and skin inflammation in adoptive transfer experiments. We will also define the regulatory elements controlling ILC2 plasticity in chromatin studies. We hope that our expertise and leadership in the ILC field will yield an integrated view of ILC functional adaptation in immunity.