Distinct mast cell responses in male and female SJL mice underlie sex dimorphic EAE susceptibility

摘要 女性更易患多种自身免疫性疾病。在多发性硬化症（MS）中，不仅有 发病率增加3-4倍，但发病平均年龄存在性别差异 和临床病程。然而，这种两性异形的细胞和分子基础仍然存在 未定义。MS的SJL小鼠模型概括了这些差异，雌性小鼠表现出更高的 发病率，更严重的疾病，和更一致的复发缓解模式比男性同行。 这种疾病易感性的差异对应于性质上不同的抗髓鞘Th细胞细胞因子 应答而雌性产生促炎性Th 1/Th 17-显性应答， 男性是Th 2-偏斜的和非致病性的。在本申请中，我们提供的证据表明，2型先天淋巴 细胞（ILC 2）发挥雄性特异性保护作用。在过敏性气道模型中研究得最好，ILC 2是c-kit+ 并且是通过产生IL-13诱导Th 2免疫所必需的。我们认为肥大细胞活化 在免疫的雄性小鼠中，诱导ILC 2活化因子如IL-33的产生，所述IL-33促进ILC 2 功能.在女性中不能产生稳健的IL-33应答导致ILC 2的功能缺陷 活动肥大细胞（c-kit+ FcεR1+）是体内IL-33的重要来源之一，睾酮直接诱导肥大细胞产生IL-33， IL 33仅在雄性来源的细胞中，尽管雌性来源的肥大细胞表达相同的雄激素受体 细胞这些数据表明睾酮的细胞和分子靶点，并确定了一个潜在的机制， 在CNS自身免疫性疾病中对睾酮介导的保护作用。 具体目的1：确定IL-33表达动力学、细胞来源及其对免疫调节剂的需求。 免疫雄性小鼠的保护作用。使用IL-33-报告小鼠（Il 33 Cit/+）或IL-33-缺陷小鼠（Il 33 Cit/Cit （IL-33缺陷型）这些实验将确定IL-33表达细胞的产生时间和地点。 具体目标2：确定睾酮如何影响IL-33和其他因子的表达， 调节性二型EAE保护。IL-33基因表达将在用以下药物治疗的小鼠中进行评价： 睾酮或雄激素受体（AR）拮抗剂。我们会问，如果睾酮诱导表观遗传变化， 赋予染色质可及性变化的Il 33基因座。还将检查其他AR靶基因。 具体目标3：探索性别决定基因对ILC 2和肥大细胞功能的贡献， EAE。性染色体对ILC 2和肥大细胞的潜在影响与激素无关 使用四个核心基因型小鼠检测基因表达和功能。

Abstract Females are more to susceptible many autoimmune diseases. In multiple sclerosis (MS), not only is there a 3-4 fold increase in disease incidence, but there are sex-determined differences in the average age of onset and clinical course. Yet the cellular and molecular underpinnings of this sex-dimorphism have remained undefined. The SJL mouse model of MS recapitulates these differences in that female mice exhibit higher incidence, more severe disease, and a more consistent relapsing-remitting pattern than their male counterparts. This difference in disease susceptibility corresponds to qualitatively distinct anti-myelin Th cell cytokine responses. Whereas females generate pro-inflammatory Th1/Th17-dominant responses, the response in males is Th2-skewed and non-pathogenic. In this application we provide evidence that type 2 innate lymphoid cells (ILC2s) exert a male-specific protective influence. Best studied in allergic airway models, ILC2s are c-kit+ and are essential for inducing Th2 immunity through production of IL-13. We propose that mast cell activation in immunized in male mice elicits production of ILC2 activating factors such as IL-33 that promote ILC2 functionality. The inability to generate a robust IL-33 response in females leads to a functional deficit in ILC2 activity. Mast cells (c-kit+ FcεR1+) are one important source of IL-33 in vivo and testosterone directly induces Il33 exclusively in male-derived cells, despite equivalent androgen receptor expression by female-derived mast cells. These data suggest a cellular and molecular target of testosterone and identify a potential mechanism of action for testosterone-mediated protection in CNS autoimmune disease. Specific Aim 1: Determine the IL-33 expression kinetics, cellular source (s) and its requirement for protection in immunized male mice. Using IL-33- reporter mice (Il33Cit/+) or IL-33-deficient mice (Il33Cit/Cit (Il33-deficient) these experiments will define the IL-33-expressing cells, when and where it is produced. Specific Aim 2: Determine how testosterone influences the expression of IL-33 and other factors that regulate sex-dimorphic EAE protection. IL-33 gene expression will be evaluated in mice treated with testosterone or androgen receptor (AR) antagonists. We will ask if testosterone induces epigenetic changes at the Il33 locus conferring changes in chromatin accessibility. Other AR target genes will also be examined. Specific Aim 3: Explore the contributions of sex determining genes on ILC2 and mast cell function in EAE. The potential effect of sex chromosomes independent of hormonal influences on ILC2 and mast cell gene expression and function will be examined using four core genotype mice.