sTNFR-IgGFc融合基因在内皮细胞中的表达及其对小鼠关节炎模型的基因治疗研究

Expression of sTNFR-IgGFc Fusion Gene in Endothelial Cell and its Application in Gene Therapy for Rheumatoid Arthritis

可溶性肿瘤坏死因子受体(sTNFR)可以拮抗肿瘤坏死因子的活性,因此已被用来治疗与TNF相关的炎性疾病。本研究将sTNFR与IgGFc片段的融合蛋白基因克隆到真核表达载体pStar上,转染到人的内皮细胞中,获得了表达。表达的sTNFR-IgGFc能够拮抗TNFα对L929细胞的细胞毒活性。将该质粒DNA与脂质体混合,经尾静脉注射到Ⅱ型胶原诱导的关节炎小鼠体内后,应用RT-PCR在鼠的肝脏检测到了sTNFR-IgGFc的表达,并显著地改善了治疗组小鼠关节炎症状和病理反应。这表明抗TNF基因治疗有可能作为治疗类风湿性关节炎的新的途径。

Tumor necrosis factor a （TNFa） is a pro-inflammatory cytokine, acting as a regulator of inflammation and immunity. TNFa plays a critical role in the pathogenesis of rheumatoid arthritis. Blocking of TNFa activity suppressed inflammatory tissue damage. In present study, the chimeric gene of soluble TNF receptor and IgG Fc fragment （sTNFR-IgGFC） was cloned into the mammalian cell expression vector pStar. When the plamid pStar/sTNFR-IgGFc-GFP was transfected into endothelial cells, a considerable expression of the sTNFR-IgG Fc fusion protein was detected. Moreover, the product in 100μL expression supernatant could completely antagonize the cytolytic effect of lng TNFa on L929 cells, even at 1/64 dilution. Then the plasmid was delivered into CIA-induced rheumatoid arthritis mice by tail vein injection. The expression of sTNFR-IgG Fc was detected in liver by RT-PCR. Animals in treatment group showed reduced symptoms of arthritis and more active. This treatment induced decrease of synovial incrassation and prevented the cartilage destruction of the mice RA model. These results show that tail vein injection is an effective way for gene therapy and sTNFR-IgGFc expression plasmid is potential for the treatment of rheumatoid arthritis.