Shaping diabetogenic T cells by IL-27 in type 1 diabetes

项目摘要 1型糖尿病（T1 D）是一种需要每天注射外源性胰岛素的终身疾病。的发生率 近几十年来，T1 D在全球范围内不断增加。遗传易感性与环境因素 以互动方式促进T1 D发展。人类基因研究已经确定了50多个基因座 与T1 D密切相关。然而，我们对这些区域内潜在基因的了解， 独立地或协同地影响细胞过程，导致破坏胰岛素产生 胰腺β细胞不完整为了填补这一空白，我们使用了基于核酸酶的方法来靶向小鼠 人T1 D候选基因的直系同源物直接在非肥胖糖尿病（NOD）小鼠中寻找功能性 它们在糖尿病发展中的作用的证据。在这项工作中，我们发现IL 27对糖尿病至关重要。 NOD小鼠的发育。CD 4和CD 8 T细胞都是T1 D发展所必需的。β细胞如何 自身反应性T细胞在T1 D进展期间被激活、积累并维持其效应子功能， 尚未完全定义。在本申请中，我们将确定IL-27影响T1 D的机制 通过它对T细胞的直接影响。IL-27通过与受体结合发挥多种免疫功能 （IL-27 Ra和gp 130异二聚体）在许多免疫细胞上表达，包括巨噬细胞、树突状细胞 (DCs)、B细胞和T细胞。我们在此表明，NOD.Il27-/-和NOD.Il27ra-/-小鼠分别 缺乏IL-27及其受体的人对糖尿病完全抵抗，表明IL-27信号传导的关键作用 在T1 D发展中。我们的研究还表明，由巨噬细胞和/或DC产生的IL-27是 足以驱动T1 D，但它们对IL-27的反应对糖尿病发展并不重要。总T细胞 IL-27-/-小鼠在转移到IL-27充足的 NOD.Rag1-/-收件人。因此，β-细胞自身反应性T细胞存在于NOD. 1127-/-小鼠中，但其致病性T细胞在NOD. 在没有IL-27的情况下不能诱导或维持活性。与此相反，分离的总T细胞， 在NOD.Rag1-/-受体中，NOD.Il27ra-/-小鼠没有诱导T1 D，表明T细胞中的直接IL-27信号转导 细胞促进糖尿病的发展。使用混合的CD 4和CD 8 T细胞转移方法，我们进一步 证明了CD 4和CD 8 T细胞中的IL-27信号传导对于T1 D进展是重要的。一 CD 4 T细胞的重要致糖尿病活性是为自身反应性CD 8 T细胞提供帮助， 识别并杀死产生胰岛素的β细胞因此，我们假设IL-27对于 通过直接作用于β细胞自身反应性CD 8 T细胞而使其蓄积并维持效应子功能 间接通过增强CD 4 T细胞的辅助功能。我们提出以下目标来检验这一点 假说. (1)为了确定IL-27内在地促进β细胞自身反应性CD 8 T细胞活化的机制， T1 D细胞(2)为了确定IL-27信号在CD 4 T细胞中支持自身反应性CD 8 T细胞的功能， T1 D中的效应器。完成拟议的实验将为未来的人类研究奠定框架。

PROJECT SUMMARY Type 1 diabetes (T1D) is a life-long disease requiring daily injections of exogenous insulin. The incidence of T1D has been increasing worldwide in recent decades. Genetic susceptibility and environmental factors interactively contribute to T1D development. Human genetic studies have identified more than 50 loci significantly linked to T1D. However, our knowledge of the underlying genes within these regions that independently or cooperatively influence cellular processes leading to the destruction of insulin producing pancreatic beta-cells is incomplete. To fill this gap, we used nuclease based approaches to target the murine orthologs of human T1D candidate genes directly in nonobese diabetic (NOD) mice to seek functional evidence of their roles in diabetes development. In this effort, we discovered that Il27 is essential for diabetes development in NOD mice. Both CD4 and CD8 T cells are required for T1D development. How beta-cell autoreactive T cells are activated, accumulate, and maintain their effector function during T1D progression has not been fully defined. In this application we will determine the mechanisms by which IL-27 impacts T1D through its direct effects on T cells. IL-27 exerts diverse immunological functions by binding to its receptors (IL-27Ra and gp130 heterodimers) expressed on many immune cells, including macrophages, dendritic cells (DCs), B cells, and T cells. We showed here that both NOD.Il27-/- and NOD.Il27ra-/- mice, respectively lacking IL-27 and its receptor, were completely resistant to diabetes, indicating a critical role of IL-27 signaling in T1D development. Our studies also demonstrated that IL-27 produced by macrophages and/or DCs was sufficient to drive T1D but their responses to IL-27 were not important for diabetes development. Total T cells isolated from NOD and NOD.Il27-/- mice were similarly diabetogenic when transferred into IL-27-sufficient NOD.Rag1-/- recipients. Thus, β-cell autoreactive T cells are present in NOD.Il27-/- mice, but their pathogenic activity cannot be induced or sustained in the absence of IL-27. In contrast, total T cells isolated from NOD.Il27ra-/- mice did not induce T1D in NOD.Rag1-/- recipients, indicating that direct IL-27 signaling in T cells promotes diabetes development. Using a mixed CD4 and CD8 T cell transfer approach, we further demonstrated that IL-27 signaling in both CD4 and CD8 T cells is important for T1D progression. One important diabetogenic activity of CD4 T cells is to provide help to autoreactive CD8 T cells that directly recognize and kill insulin-producing beta-cells. Therefore, we hypothesize that IL-27 is important for the accumulation and sustained effector function of beta-cell autoreactive CD8 T cells by directly acting on them and indirectly through enhancing the helper function of CD4 T cells. We propose the following aims to test this hypothesis. (1) To identify the mechanisms by which IL-27 intrinsically promotes beta-cell autoreactive CD8 T cells in T1D. (2) To determine the function of IL-27 signaling in CD4 T cells for supporting autoreactive CD8 T effectors in T1D. Completion of the proposed experiments will lay the framework for future human studies.