HLA分子重构法检测多肽与HLA-B*1301的结合力

Measurement of binding affinity between peptides and HLA-B*1301 by HLA molecular reconstitution

目的:建立弱酸处理后细胞表面HLA分子重构法检测多肽与HLA-B*1301的结合力,并评估其实用性。方法:采用不同pH的柠檬酸缓冲液处理高表达HLA-B*1301的C1R细胞不同时间,中和pH后用含β2m蛋白、布雷非德菌素A的培养液重悬细胞,加入多肽(多肽组)或不加多肽(空白对照)37℃孵育,加入抗HLA抗体后采用流式细胞术检测,以多肽组与空白对照组荧光强度的比值作为衡量HLA分子重构水平强弱的指标,进而代表多肽与HLA-B*1301分子的结合力。结果:pH3.0的缓冲液处理1 min的条件下,HLA-多肽复合物变性解离,细胞表面只保留HLA重链分子,添加具有结合力的多肽可显著提升HLA分子重构水平,可以此评价多肽与HLA-B*1301的结合力。结论:HLA分子重构法检测多肽与HLA-B*1301的结合力操作简便,结果可靠,也可为研究其他低频HLA分子抗原递呈模式提供参考。

Objective:To establish a method for detecting the binding affinity of peptides to HLA-B*1301 by HLA molecular reconstitution after weak acid treatment,and its practicality was evaluated.Methods:C1R cells overexpressing HLA-B*1301 were treated with citrate buffer of different pH for different time.After neutralization of pH,cells were resuspended in culture medium con⁃tainingβ2m and brefeldin A.Cells were incubated at 37℃with peptide(peptide group)or without peptide(blank control),after addition of anti-HLA antibody,the cells were detected by flow cytometry.Ratio of fluorescence intensity between peptide group and blank control group was used as an index to measure the level of HLA molecular remodeling,and then represented the interactions between peptide and HLA-B*1301 molecule.Results:HLA-polypeptide complex was denatalized and dissociated after being treated with pH3.0 buffer for 1 min,and only HLA heavy chain molecules were retained on the cell surface.The addition of peptides with binding force could significantly improve the level of HLA molecular remodeling,and the binding force of peptides with HLA-B*1301 could be evaluated by this method.Conclusion:HLA molecular reconstitution assay is a simple and reliable method to detect the binding of peptides to HLA-B*1301,which can also provide reference for the study of other low frequency HLA molecular antigen pre⁃sentation patterns.