Smeets R L, van de Loo F A J, Joosten L A B, Arntz O J, Bennink M B, Loesberg W A, Dmitriev I P, Curiel D T, Martin M U, van den Berg W B
University Medical Center Nijmegen, Nijmegen, The Netherlands.
Arthritis Rheum. 2003 Oct;48(10):2949-58. doi: 10.1002/art.11234.
To investigate whether the soluble form of interleukin-1 (IL-1) receptor accessory protein (sIL-1RAcP), whose physiologic function remains to be established, can serve as a specific inhibitor of IL-1 signaling in vitro, and to evaluate its applicability in collagen-induced arthritis (CIA).
Soluble IL-1RAcP was cloned from murine liver complementary DNA and expressed by the use of either an adenoviral vector (AdRGD) for sIL-1RAcP or a stable-transfected NIH3T3 fibroblast cell line. The ability of affinity-purified sIL-1RAcP to inhibit IL-1 signaling was tested on NF-kappaB luciferase reporter fibroblasts and quantified by luminometer. To investigate therapeutic efficacy, sIL-1RAcP was both locally (knee joint) and systemically overexpressed in collagen-immunized male DBA/1 mice. Severity of arthritis was monitored visually, and the pathologic process in the joint was examined histologically. Serum was obtained from mice to quantify IL-6 and anti-bovine type II collagen (BCII) antibody levels.
Incubation of the NF-kappaB reporter fibroblast with purified sIL-1RAcP protein showed a marked reduction of IL-1-induced, but not tumor necrosis factor-induced, NF-kappaB activation. This showed a novel role for sIL-1RAcP as a specific inhibitor of IL-1 signaling. Local transplantation of sIL-1RAcP-producing NIH3T3 fibroblasts into the knee before onset of CIA had little or no effect on general disease severity in these mice. Histologic evaluation of the knee joints receiving sIL-1RAcP cell transplantation showed a marked reduction in both joint inflammation and bone and cartilage erosion. Local treatment with sIL-1RAcP had no profound effect on serum levels of IL-6 and anti-BCII antibodies, which is indicative of the ongoing presence of arthritis in distal joints. In contrast to local treatment, systemic treatment with the AdRGD for sIL-1RAcP markedly ameliorated CIA in all joints.
In this study we demonstrated that sIL-1RAcP is a biologically active and innovative inhibitor of IL-1, and treatment of mice with sIL-1RAcP had a profound prophylactic effect on collagen-induced arthritis.
研究白细胞介素-1（IL-1）受体辅助蛋白的可溶性形式（sIL-1RAcP），其生理功能尚待确定，能否在体外作为IL-1信号传导的特异性抑制剂，并评估其在胶原诱导的关节炎（CIA）中的适用性。
从鼠肝互补DNA中克隆可溶性IL-1RAcP，并通过使用用于sIL-1RAcP的腺病毒载体（AdRGD）或稳定转染的NIH3T3成纤维细胞系进行表达。在NF-κB荧光素酶报告基因成纤维细胞上测试亲和纯化的sIL-1RAcP抑制IL-1信号传导的能力，并通过光度计进行定量。为了研究治疗效果，在胶原免疫的雄性DBA/1小鼠中局部（膝关节）和全身过表达sIL-1RAcP。通过肉眼监测关节炎的严重程度，并通过组织学检查关节中的病理过程。从小鼠获得血清以定量IL-6和抗牛II型胶原（BCII）抗体水平。
用纯化的sIL-1RAcP蛋白孵育NF-κB报告基因成纤维细胞显示，IL-1诱导的而非肿瘤坏死因子诱导的NF-κB活化明显降低。这表明sIL-1RAcP作为IL-1信号传导的特异性抑制剂具有新的作用。在CIA发作前将产生sIL-1RAcP的NIH3T3成纤维细胞局部移植到膝关节中对这些小鼠的总体疾病严重程度几乎没有影响。接受sIL-1RAcP细胞移植的膝关节的组织学评估显示关节炎症以及骨和软骨侵蚀均明显减少。用sIL-1RAcP进行局部治疗对血清IL-6水平和抗BCII抗体没有深远影响，这表明远端关节中存在持续的关节炎。与局部治疗相反，用AdRGD对sIL-进行全身治疗可明显改善所有关节的CIA。
在本研究中，我们证明sIL-1RAcP是一种具有生物活性的新型IL-1抑制剂，用sIL-1RAcP治疗小鼠对胶原诱导的关节炎具有深远的预防作用。
