HLA-G突变分子对NK细胞抑制作用的研究

A mutant HLA-G can inhibit nature killer cell’s cytotoxicity

目的探索可溶性HLAG1分子结构对功能的影响,为其临床应用打下基础。方法通过分子克隆技术,去掉HLAG1重链分子α1功能区氨基端24肽,然后与轻链蛋白在体外与九肽共折叠复性形成复合物,并检测复合物对NK细胞杀伤活性的影响。结果成功构建突变的HLAG1重链分子的原核表达载体,表达的重链蛋白与轻链蛋白形成复合物,经Westernblot鉴定可与HLAⅠ类分子的单抗W6/32结合,并且可明显抑制NK细胞对K562细胞的细胞毒作用。结论α1功能区氨基端缺失24肽的HLAG1分子,可抑制NK细胞的细胞毒作用。

Objective To construct mutant soluble HLA-G1 heavy chain, and investigate whether its structure mutation may affect its biologic function.Methods The sHLA-G1 heavy chain sequence with its alpha1 domain 24 peptide deleted,was amplified by PCR ,and the fragment was inserted into pET28a(+) expression vector, the sHLA-G1 heavy chain was expressed highly as insoluble aggregates in E.coli. The two subunits were refolded to form an HLA-G1-peptide complex identified by Western-blot with mAb W6/32 .The effect of soluble HLA-G1 protein on NK's cytotoxicity was evaluated. Results The refolded complex was recognized by mAb W6/32; Soluble mutant HLA-G1 protein could effectively inhibit NK's cyotoxicity to K562 cells. Conclusion The refolding of soluble HLA-G1-peptide complex was performed in vitro;the complex could inhibit the function of NK cells.