Aim: To construct the human TAP1 expression vector and to evaluate its effects on HLA-I expression in GES-1 cells in vitro.
Methods: The human TAP1 expression vector (pcDNA3.1/V5-His-TAP1) was constructed by gene recombination technology. The expression of HLA-I on human gastric epithelial cell line (GES-1 cells) after transfection was detected by RT-PCR, Western blot and flow cytometry (FCM).
Results: Human full-length TAP1 gene was obtained from human peripheral blood mononuclear cells by RT-PCR reaction, then TAP1 gene was inserted into pcDNA3.1/V5-HisB vector to get the TAP1 expression vector (pcDNA3.1/V5-His-TAP1) by recombination technology including digestion with restriction enzymes, ligation and transformation. The vector was sequenced to ensure the sequence fidelity.To further evaluate the function of the TAP1 plasmid we constructed, GES-1 cells were selected as the target cell to be transfected. Firstly RT-PCR and Western blot results showed that the expression of TAP in GES-1 cells was increased after pcDNA3.1/V5-His-TAP1 transfection. Based on the high efficiency of transfection in GES-1 cell, we then detected the expression of HLA-I. The results showed that the expressions of HLA-A, HLA-B and HLA-C at mRNA level were all increased by TAP1 transfection, but no change was found in beta2m mRNA. HLA-I protein level was increased correspondingly with the TAP expression in cells by FCM and Western blot assay.
Conclusion: The TAP1 expression vector was successfully constructed, and it can induce the expression of HLA-I on the GES-1 cells after TAP1 transfection. The results confirm that the TAP1 plays a cruical role in the HLA-I antigen expression and antigen presentation pathway.