基于MHC—Ⅱ限制性途径的抗原定向呈递系统原理介绍

基于MHC—Ⅱ限制性途径的抗原定向呈递系统是一项生物工程技术，可用于寻找自身免疫耐受性抗原和肿瘤特异性抗原。此项技术源于MHC—Ⅱ亚型偏向性呈递具有相似锚着残基表位序列的特性、恒定链引导抗原表位与MHC—Ⅱ结合的生理作用及TCR克隆特异性识别单一抗原表位的特点。将抗原表位与恒定链融合改造，利用特定MHC—Ⅱ亚型可实现抗原表位的定向性呈递。之后利用TCR特异性识别抗原表位的作用可鉴定出肿瘤特异抗原。

The introduction on the principle of directional antigen presentation system based on MHC-H restric-tion

The antigen direetionally presenting system by MHC—Ⅱ -restricted pathway is designed in or- der to seek immune tolerance antigens and tumor specific antigens. Developing of this technology is based on following nature principles：The MHC—Ⅱ function that a MHC—Ⅱ subtype is highly affinitive to antigen epitopes with specific anchor residues ; The physiological function of invariant chain （Ii） which can induce the combina-tion between MHC—Ⅱ and epitopes ; One clone TCR recognizes a single specific epitope ; Specific epitope presen-tation can be achieved by fuse with invariant chain and then direct interact with a specific MHC-Ⅱ subtype to form a MHC-Ⅱ-epitope complex. The complex can be then recognized by the TCR clone that fits this epitope. Thus, it is possible to utilize the epitope-specific TCR to identify the existence of tumor soecific antigen.