Dysregulation of CXCR5+ B Helper T Cell Subsets in Dermatamyositis

幼年型皮肌炎是一种自身免疫性炎症性肌病。CD 4 + T细胞和B 细胞是最普遍的，自身免疫的证据是经常与高滴度的自身抗体观察到， 60-80%的成人患者和高达40%的儿科患者的血清。临床试验结果， 抗-CD 20清楚地表明B细胞在DM的发病机制和临床表现中的作用。而 已经研究了糖尿病患者的自身抗体应答，CD 4 + T细胞亚群可能与糖尿病相关。 自身反应性B细胞的分化尚不清楚。在初步研究中，我们发现， 皮肌炎患者CXCR 5 + CD 4 + T细胞亚群偏向CXCR 3-CCR 6-Th 2， CXCR 3-CCR 6 + Th 17细胞与年龄匹配的健康儿童相比， 包括银屑病关节炎和系统性红斑狼疮（SLE）的疾病。这些B辅助T细胞可能 是DM中自身反应性B细胞分化的主要驱动力，从而有助于疾病发病机制。 因此，它们在DM中的发展和功能需要建立。我们进一步表明， B辅助T细胞的分化由髓样树突细胞（DC）（间质DC）的亚群介导。 IL-12是诱导naTve CD 4 + T细胞成为分泌IL-21的B辅助性T细胞的关键DC衍生因子 细胞这些结果构成了我们假设的基础：CXCR 5 + B辅助性T细胞和IL-12的改变 产生抗原呈递细胞有助于幼年/成年中自身反应性B细胞发育 皮肌炎AIM 1将确定CXCR 5 + B辅助性T细胞的表型和频率， 青少年/成人DM患者。目的2检测糖尿病患者外周血CXCR 5 + CD 4 + T细胞的功能 患者AIM 3将确定抗原呈递细胞（APC）的细胞因子分泌模式， DM患者我们期望，这种对B辅助性T细胞表型和功能的全面分析， 细胞、B细胞和APC在DM患者中的表达将为我们了解DM的发病机制提供帮助， 建立新的疾病生物标志物。在临床试验中的患者组中，这将特别具有信息性 概念1，其中DM患者将接受IL 1阻断。

Juvenile dermatomyositis (JDM) is an autoimmune inflammatory myopathy disease. CD4+ T cells and B cells are most prevalent, and evidence of autoimmunity is frequent with high-titer autoantibodies observed in the sera of 60-80% of adult patients and up to 40% of pediatric patients. Results from clinical trials with anti-CD20 clearly suggest the role of B cells in the pathogenesis and clinical manifestations of DM. While autoantibody responses have been studied in DM, the CD4+ T cell subsets which might be associated with the differentiation of autoreactive B cells are not understood. In preliminary studies, we have found that the CXCR5+CD4+ T cell subsets in dermatomyositis are skewed towards CXCR3-CCR6- Th2 and CXCR3-CCR6+ Th17 cells when compared to age-matched healthy children, and other autoimmune diseases including psoriatic arthritis and systemic lupus erythematosus (SLE). These B-helper-T cells might be the main drivers of autoreactive B cells differentiation in DM thus contributing to disease pathogenesis. Therefore, their development and function in DM need to be established. We have further shown that differentiation of B-helper-T cells is mediated by a subset of myeloid dendritic cells (DCs) (interstitial DCs). IL-12 is the critical DC-derived factor that induces naTve CD4+ T cells to become IL-21-secreting B-helper-T cells. These results form the basis for our hypothesis: Alterations in CXCR5+ B helper T cells and IL-12 producing Antigen Presenting Cells contribute to autoreactive B cell development in juvenile/adult dermatomyositis. AIM 1 will determine the phenotype and frequency of CXCR5+ B-helper-T cells in juvenile/adult DM patients. AIM 2 will determine the function of blood CXCR5+CD4+ T cells from DM patients. AIM 3 will determine the cytokine secretion pattern of Antigen Presenting Cells (APCs) from patients with DM. We expect that this comprehensive analysis of the phenotype and function of B-helper-T cells, B cells and APCs in DM patients will bring insights into the DM pathogenesis as well as help us establish novel disease biomarkers. It will be particularly informative in the group of patients in Clinical Trial Concept 1 where DM patients will receive IL1 blockade.