利用植物质体转基因技术高效表达抗人源白介素6单链抗体

High-level expression of anti-interleukin-6 single chain variable fragment through plastid transformation technology

摘要:

白介素6（interleukin-6，IL-6）是与包括癌症在内的多种疾病相关的一种多功能细胞因子，免疫疗法利用抗人源IL-6抗体来治疗相关疾病取得了很好的治疗效果。植物作为生物反应器可以有效降低药用蛋白的生产成本，同时积累功能蛋白。通过基因枪轰击和再生筛选，得到了2个在烟草质体中表达了鼠源抗人源IL-6单链抗体（single chain variable fragment，scFv）的独立株系，并用Southern blotting鉴定了质体转化烟草的同质化状态。抗人源IL-6 scFv基因在质体转基因烟草中成功转录和翻译，功能性抗人源IL-6 scFv在质体转基因烟草叶片中的含量占到总可溶性蛋白的1%，达到41 mg/kg鲜重。另外，质体转基因烟草的表型与野生型烟草相比并没有显著差异，它们具有相似的生长速率、成熟植株的株高以及果荚数目。抗人源IL-6 scFv的高表达量也表明了利用质体转基因植物低成本生产scFv的潜力。

关键词:质体转基因技术;白介素6;单链抗体;植物生物反应器;免疫疗法

Abstract:

Interleukin-6 (IL-6) is a pleiotropic cytokine which participates in the pathogenesis of a variety of clinical disorders, including many kinds of cancers. Anti-IL-6 antibody was proved to be useful for the immunotherapy of various inflammatory diseases. Plants are low-cost platforms for producing specific proteins of therapeutic interest. Two dependent transplastomic tobacco lines expressing murine anti-IL-6 single chain variable fragment (scFv) were generated after bombardment and regeneration, homoplasmy was then verified by Southern blotting analysis. The anti-IL-6 scFv gene was successfully expressed at both transcriptional and translational levels in transplastomic tobacco plants. Functional anti-IL-6 scFv accumulated to 1% of total soluble proteins, namely 41 mg/kg fresh weight. There was no obvious phenotypic difference between the wild-type and the transplastomic tobacco plants, including the growth rate, the height of mature plants and the number of siliques. The high-level expression of anti-IL-6 scFv indicates the potential for cost-effective production of scFV using transplastomic plants.

Key words:plastid transformation technology;interleukin-6;single chain variable fragment;plant bioreactor;immunotherapy