人源Na（？）ve Fab抗体库的构建和抗Met抗体片断的筛选及特征鉴定

发布时间：2019-04-15 19:54

【摘要】：Met是一类酪氨酸激酶受体,其唯一的配体是肝细胞生长因子/扩散因子(Hepatocyte Growth Factor/Scatter Factor, HGF/SF)。细胞内Met首先表达为无活性的前体肽,然后经酶切割为α(Mr 45,000)和β(Mr 145,000)两个亚基,二亚基以二硫键结合为异二聚体而发挥生物学功能。α亚基位于胞外,β亚基由胞外,跨膜和胞内三个结构域组成,胞内结构域含有酪氨酸激酶区。HGF/SF与Met受体的β亚基胞外结构域结合即可激活胞内的信号通路。对于哺乳动物,HGF/SF和Met所介导的信号通路在胚胎发育中的器官形成以及成人组织损伤后的修复等生理过程申起重要作用。但HGF/SF和Met的过表达常与一些恶性肿瘤的侵袭,转移和血管生成密切相关,并预后不良。HGF/SF和Met已不仅成为恶性肿瘤的标志物,大量研究已把其确立为肿瘤治疗的靶向分子。目前广泛开展的针对HGF/SF和Met的肿瘤治疗方案包括,应用酪氨酸激酶受体的反义分子,酪氨酸激酶抑制剂,HGF/SF或/和Met拮抗剂,以及抗Met受体或抗HGF/SF的抗体等。抗人Met和HGF/SF的鼠源抗体分子已被制备,其中不少在体外实验和动物肿瘤模型中显示较强的亲和力和阻断功能,但由于鼠源单抗的异源性(如在人体多次使用可产生人抗鼠抗体而导致超敏反应)及其它一些药代动力学问题阻碍了其在人体内的应用。近年来噬菌体抗体呈现技术通过使用来自于人体免疫组织而构建抗体库,使得筛选出抗体均为全人源从而克服了上述缺点。该技术与生物筛选法的优化结合可使得筛选出的抗体分子具有良好的特异性。
[Abstract]:Met is a tyrosine kinase receptor, and its only ligand is hepatocyte growth factor / diffusion factor (Hepatocyte Growth Factor/Scatter Factor, HGF/SF. Intracellular Met was first expressed as an inactive precursor peptide, and then digested into 伪 (Mr 45000) and 尾 (Mr 145000) subunits. The two subunits performed biological functions by disulfide bond binding as heterodimers. 伪 subunit was located outside the cell. 尾 subunit is composed of extracellular domain, transmembrane domain and intracellular domain, which contains tyrosine kinase domain. The binding of HGF / SF with the extracellular domain of 尾 subunit of Met receptor can activate the intracellular signaling pathway. The signaling pathways mediated by HGF/SF and Met play an important role in the development of embryos and the repair of adult tissues after injury. However, the overexpression of HGF/SF and Met is closely related to the invasion, metastasis and angiogenesis of some malignant tumors, and the prognosis is poor. HGF / SF and Met have not only become markers of malignant tumors. A large number of studies have established it as a target molecule for tumor therapy. Currently, anti-Met receptor antisense molecules, tyrosine kinase inhibitors, HGF/SF or / and Met antagonists, and anti-Met receptor or anti-HGF/SF antibodies have been widely used in the treatment of HGF/SF and Met. Mouse-derived antibodies against human Met and HGF/SF have been prepared, many of which have strong affinity and blocking function in vitro experiments and animal tumor models. However, its application in human body has been hindered by the heterogenous origin of mouse monoclonal antibody (such as the hypersensitivity of human anti-mouse antibody produced by repeated use in human body) and some other pharmacokinetic problems. In recent years, phage antibody presentation techniques have overcome these shortcomings by using antibody libraries derived from human immune tissues to screen out all human antibodies. The optimized combination of this technique and biological screening method can make the selected antibody molecules have good specificity.
【学位授予单位】：南京医科大学
【学位级别】：博士
【学位授予年份】：2005
【分类号】：R392

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