Aim: To form soluble HLA-G1-peptide complex by refolding in vitro, and to study its immune function.
Methods: The heavy chain and beta(2m) of sHLA-G1 were expressed as insoluble aggregates in E. coli, and then the two subunits were refolded to form HLA-G1-peptide complex by dilution method in the presence of specific peptide. The refolded product was purified through Sephadex G-75 gel filtration. The purified product was identified by Western blot with mAb W6/32. The function of soluble HLA-G1 was explored from following three aspects, namely, the influences on cytotoxicity of NK cells, on proliferation of T cells in mixed lymphocyte culture and apoptosis of activated T cells.
Results: The refolded complex was recognized by mAb W6/32. It effectively inhibited cytotoxicity of NK cells and proliferation of T cells, and induced apoptosis of activated T cells.
Conclusion: The refolding of soluble HLA-G1-peptide complex has been successfully realized in vitro. The complex can inhibit the functions of NK cells and T cells.