Rheumatology Research and Advanced Therapeutics, Department of Rheumatology, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500HB, Nijmegen, The Netherlands.
Ann Rheum Dis. 2010 Oct;69(10):1866-72. doi: 10.1136/ard.2009.127399. Epub 2010 May 14.
To investigate the potential synergism between interleukin (IL) 32γ and Streptococcus pyogenes cell wall (SCW) fragments in the development of destructive arthritis.
An adenoviral vector encoding human IL-32γ (AdIL-32γ) was constructed and validated in HeLa cells. Fibroblast-like synoviocytes (FLS) were transduced with AdIL-32γ and stimulated with Toll-like receptor 2 (TLR-2) and nucleotide oligomerisation domain (NOD) 2 ligands. Expression levels of several proinflammatory cytokines, chemokines, matrix degrading enzymes, TLR-2 and NOD2 were measured by quantitative real-time PCR. Furthermore, IL-6 and CXCL8 protein levels were determined. In-vivo synergy between IL-32γ and SCW was studied by intra-articular injection of AdIL-32γ in C57Bl/6 mice followed by SCW injection. The contribution of endogenous IL-1 was assessed in mice deficient for both IL-1α and IL-1β.
IL-32γ synergise with TLR-2/NOD2 ligands to induce proinflammatory cytokines, chemokines and matrix degrading enzymes in AdIL-32γ-transduced FLS. In mice, AdIL-32γ transduction followed by the injection of SCW displayed aggravated joint inflammation and cartilage destruction. However, IL-1-deficient mice were protected against IL-32γ/SCW-induced joint changes, indicating a requirement for IL-1 in downstream events triggered by IL-32γ plus SCW. To elucidate the synergistic mechanism, the authors investigated the expression of two pattern recognition receptors involved in sensing SCW fragments. TLR-2 and NOD2 receptor expression was enhanced by IL-32γ and Pam3Cys/muramyl dipeptide stimulation in FLS.
Here the authors show that IL-32γ aggravates SCW-induced arthritis by the upregulation of TLR-2/NOD2 expression and promotes severe joint erosion in an IL-1-dependent fashion. Targeting of IL-32γ may provide a novel therapy to prevent destructive arthritis.
研究白细胞介素（IL）32γ与化脓性链球菌细胞壁（SCW）片段在破坏性关节炎发展中的协同作用。
构建并在 HeLa 细胞中验证了编码人 IL-32γ（AdIL-32γ）的腺病毒载体。用 AdIL-32γ转导成纤维样滑膜细胞（FLS），并用 Toll 样受体 2（TLR-2）和核苷酸寡聚化结构域（NOD）2 配体刺激。通过实时定量 PCR 测量几种促炎细胞因子、趋化因子、基质降解酶、TLR-2 和 NOD2 的表达水平。此外，还测定了 IL-6 和 CXCL8 蛋白水平。通过在 C57Bl/6 小鼠关节内注射 AdIL-32γ，然后注射 SCW，研究 IL-32γ与 SCW 之间的体内协同作用。在缺乏 IL-1α 和 IL-1β 的小鼠中评估内源性 IL-1 的作用。
IL-32γ与 TLR-2/NOD2 配体协同作用，诱导 AdIL-32γ 转导的 FLS 中促炎细胞因子、趋化因子和基质降解酶。在小鼠中，AdIL-32γ 转导后注射 SCW 显示出关节炎症和软骨破坏加重。然而，IL-1 缺陷型小鼠对 IL-32γ/SCW 诱导的关节变化有保护作用，表明 IL-1 在 IL-32γ 加 SCW 触发的下游事件中起作用。为了阐明协同作用机制，作者研究了两种参与识别 SCW 片段的模式识别受体的表达。IL-32γ 和 Pam3Cys/muramyl dipeptide 刺激增强了 FLS 中 TLR-2 和 NOD2 受体的表达。
作者表明，IL-32γ 通过上调 TLR-2/NOD2 表达加重 SCW 诱导的关节炎，并以 IL-1 依赖的方式促进严重的关节侵蚀。靶向 IL-32γ 可能为预防破坏性关节炎提供一种新的治疗方法。
