靶向幽门螺杆菌毒力因子HtrA鲨鱼纳米抗体的开发

目的 构建鲨鱼纳米抗体噬菌体展示文库,从中筛选出针对幽门螺杆菌关键毒力因子HtrA的鲨鱼纳米抗体。方法 用重组的HtrA蛋白免疫条纹斑竹鲨,从其外周血白细胞(PBLs)和脾脏组织中克隆鲨鱼纳米抗体（VNAR）的编码序列,构建鲨鱼纳米抗体噬菌体展示文库,并从中筛选出抗HtrA的鲨鱼纳米抗体。利用大肠杆菌表达系统对鲨鱼纳米抗体进行重组表达并纯化,并用ELISA检测了鲨鱼纳米抗体的亲和力和稳定性。结果 成功构建了针对HtrA的纳米抗体噬菌体展示文库,筛选出了两个鲨鱼纳米抗体(G11和1A5),分别在大肠杆菌BL21(DE3)细胞中表达,纯化后进行进一步鉴定。评价了鲨鱼纳米抗体的亲和力和稳定性,G11和1A5的EC50值分别为21.2 nM和27.3 nM,并且在低pH溶液中表现出较高的稳定性。构建了1A5的双价鲨鱼纳米抗体,明显提高了抗原结合活性。     

Screening and anti-glioma activity of Chiloscyllium plagiosum anti-human IL-13Rα2 single-domain antibody

Glioblastoma is a common and fatal malignant tumour of the central nervous system, with high invasiveness. Conventional treatments for this disease, including comprehensive treatment of surgical resection combined with chemoradiotherapy, are ineffective, with low survival rate and extremely poor prognosis. Targeted therapy is promising in overcoming the difficulties in brain tumour treatment and IL-13Rα2 is a widely watched target. The development of new therapies for glioma, however, is challenged by factors, such as the unique location and immune microenvironment of gliomas. The unique advantages of single-domain antibodies (sdAbs) may provide a novel potential treatment for brain tumours. In this study, Chiloscyllium plagiosum was immunized with recombinant IL-13Rα2 protein to produce sdAb and sdAb sequences were screened by multi-omics. The targeted sdAb genes obtained were efficiently expressed in the Escherichia coli prokaryotic expression system, showing a significant binding capacity to IL-13Rα2 in vitro. The cell proliferation and migration inhibitory effects of recombinant variable domain of the new antigen receptor (VNAR) on glioma cells were detected by CCK-8 and cell scratch assays. The sdAb obtained in this study showed high in vitro activity and favourable cell proliferation inhibitory effect on glioma cells, with potential clinical application value. The present study also provides a new direction and experimental basis for the development of targeted therapies for glioma.     

靶向幽门螺杆菌UreB鲨鱼纳米抗体的筛选与鉴定

目的 开发靶向幽门螺杆菌（H. pylori）尿素酶B亚基（UreB）的鲨鱼纳米抗体。方法 利用大肠杆菌表达系统对UreB进行重组表达,纯化后对条纹斑竹鲨进行免疫,通过间接ELISA检测免疫后鲨鱼血浆的抗体效价。提取鲨鱼外周血淋巴细胞及脾脏组织的总RNA,反转录成cDNA,PCR扩增鲨鱼纳米抗体片段,构建鲨鱼纳米抗体噬菌体展示文库。扩增噬菌体文库,采用固相淘选,通过噬菌体多克隆ELISA检测特异性噬菌体的富集程度。随后通过单克隆ELISA鉴定阳性噬菌体,并通过序列比对,确定靶向UreB的鲨鱼纳米抗体序列。构建鲨鱼纳米抗体重组表达质粒,利用大肠杆菌表达系统制备重组鲨鱼纳米抗体。通过ELISA检测鲨鱼纳米抗体对重组UreB和H. pylori菌株的结合能力。结果 成功制备了重组UreB蛋白,用于免疫鲨鱼,经6次免疫后构建了库容量为1.28×108 CFU的鲨鱼纳米抗体噬菌体展示文库。淘选到的两株靶向UreB的鲨鱼纳米抗体,具有较高的亲和力,其中1E3可特异性结合H. pylori。结论 成功筛选到靶向UreB鲨鱼纳米抗体,为H. pylori感染的诊断和治疗药物的开发奠定了基础。