Abstract:

Objective Prokaryotic system was used to induce expression and purification of human leukocyto antigen-G1（HLA-G1） protein and to investigate the effect of HLA-G1 on expression of interleukin-10 （IL-10）in hunman B lymphocytes， to study the B cell-mediated immune tolerance mechanism of HLA-G1 in kidney transplantation recipients. Methods We used the prokaryotic expression system to express the HLA-G1 protein and purified it. Human peripheral blood mononuclear cells（PBMCs） were co-cultured with HLA-G1 after Western Blot. Then we detected the expression of IL-10 in B lymphocytes by flow cytometry. Results Results of sodium dodecyl sulfate-polyacrylamide gel（SDS-PAGE） and Western Blot showed that the molecular weight of the purified protein was about 38.2 kDa which was in accord with that of HLA-G1 protein. The expression of IL-10 in B lymphocytes after co-culture with HLA-G1 significantly increased， and the rate of IL-10 on B lymphocytes were 0.1%，0.36%，0.57% and 0.73%， respectively， dependent on the concentration of HLA-G1（concentration gradient： 0，50，100 and 200 ng/ml）. Conclusion We used the prokaryotic expression system to express HLA-G1 protein and purified it. The purity was above 95%. HLA-G1 protein induced the expression of IL-10 in B lymphocytes in a concentration dependent manner after co-culture with human PBMC， which suggested that HLA-G1 might play an important role in the establishment of immune tolerance in kidney transplantation.