A multidimensional blood stimulation assay reveals immune alterations underlying systemic juvenile idiopathic arthritis [RNA-Seq]

Despite great scientific and technological advances, immune alterations predisposing to sporadic human inflammatory diseases remain mostly unknown. To fill this gap, we developed a strategy to evaluate blood leukocyte responses to innate stimuli, simultaneously at the transcriptional, cellular and secreted protein levels. The data were integrated using weighted gene co-expression network analysis. When applied to systemic juvenile idiopathic arthritis (sJIA), an autoinflammatory disease of unknown etiology, this approach identified gene sets associated with specific cytokine environments and activated leukocyte subsets. During the remission phase of disease and off treatment, sJIA patients displayed dysregulated responses to TLR4, TLR8 and TLR7 stimulation in blood. Isolated sJIA monocytes accumulated higher levels of intracellular IL-1β after stimulation, and underexpressed the IL-1 inhibitor AHR at baseline. In line with the recent demonstration that AHR downregulation in monocytes is linked to macrophage differentiation, we show that the differentiation of sJIA monocytes in vitro was skewed towards macrophages, away from dendritic cell phenotype. This might contribute to the increased incidence of macrophage activation syndrome in these patients. The integrated analysis of these high-dimensional data can thus help unravel underlying immune alterations predisposing to complex inflammatory diseases. 32 total samples, 4 control healthy in vitro, 6 control systemic JIA in vitro, 4 LPS healthy in vitro, 6 LPS systemic JIA in vitro, 5 healthy ex vivo, 7 systemic JIA ex vivo

尽管当前科学与技术已取得长足进步，但导致散发性人类炎症性疾病的易感免疫异常仍大多未被明确认知。为填补这一研究空白，我们开发了一套可同时从转录组、细胞层面及分泌蛋白组水平评估血液白细胞对天然免疫刺激应答的研究策略，并采用加权基因共表达网络分析（weighted gene co-expression network analysis）对所得数据进行整合分析。将该策略应用于病因未明的自身炎症性疾病——系统性幼年特发性关节炎（systemic juvenile idiopathic arthritis, sJIA）时，本方法成功鉴定出与特定细胞因子微环境及活化白细胞亚群相关的基因集。在疾病缓解期且停止治疗的情况下，系统性幼年特发性关节炎患者的血液白细胞对Toll样受体4（TLR4）、Toll样受体8（TLR8）与Toll样受体7（TLR7）刺激的应答呈现失调状态。分离得到的系统性幼年特发性关节炎患者单核细胞在受刺激后，胞内白细胞介素1β（IL-1β）的积累水平更高，且在基线状态下IL-1抑制剂芳香烃受体（aryl hydrocarbon receptor, AHR）的表达水平更低。结合近期有研究证实单核细胞中芳香烃受体的下调与巨噬细胞分化相关，本研究发现系统性幼年特发性关节炎患者的单核细胞在体外分化时会偏向巨噬细胞谱系，而非树突状细胞表型，这或许是此类患者巨噬细胞活化综合征发病率升高的潜在原因之一。因此，对这些高维数据的整合分析有助于阐明易感复杂炎症性疾病的潜在免疫异常机制。本研究共纳入32份样本，具体分组如下：体外实验健康对照组样本4份、体外实验系统性幼年特发性关节炎对照组样本6份、脂多糖（lipopolysaccharide, LPS）处理的体外健康对照组样本4份、脂多糖处理的体外系统性幼年特发性关节炎样本6份、离体健康样本5份以及离体系统性幼年特发性关节炎样本7份。