[Establishment of stable subline of K562 cells expressing human leucocyte antigen a1101]

The aim of this study was to establish a stable subline of K562 cells expressing the HLA-A(*)1101 protein, which was expected to provide target cells for characterizing the HLA-I restrictive antigen specific cytotoxic T lymphocyte (CTL) effects against chronic myeloid leukemia (CML). The HLA-A(*)1101 protein encoding gene was amplified from peripheral blood mononuclear cell (PBMNC) of CML patient by RT-PCR; the 2A peptide linker (D-V-E-X-N-P-G-P) gene was linked to the 3'terminal of the HLA-A(*)1101 gene by recombinant PCR, then the recombinant was cloned into the pEGFP-N3 plasmid which contains an enhanced green fluorescent protein gene, and the eukaryotic recombinant expression vector containing HLA-A(*)1101-T2A-EGFP transcription box was constructed; the pEGFP-N3 vector and recombinant vector was separately electroporated into K562 cells. The expression of GFP was monitored by fluorescence microscopy, finally stably transfected sublines of K562 cells containing HLA-A(*)1101 gene, and of K562 containing pEGFP-N3 vector were obtained by G418 selection; the transcriptional or translational expression of HLA-A(*)1101 gene was detected with RT-PCR and flow cytometry respectively. The results indicated that the eukaryotic expression vector HLA-A(*)1101-T2A-EGFP plasmid was successfully constructed; after G418 selection for 2 months, two sublines of K562 cells (HLA-A(*)1101(+)K562, pEGFP-N3(+)K562) expressing GFP were constructed. The expression of HLA-A*A1101 gene could be determined in HLA-A(*)1101(+)K562 cell line by RT-PCR, while the pEGFP-N3(+)K562 cells could not express HLA-A*A1101 gene. HLA-A(*)1101 protein and GFP double positive HLA-A(*)1101(+)K562 cells were up to 88.5%, which was obviously higher than pEGFP-N3(+)K562 cells (0.698%) by flow cytometric analysis. It is concluded that a simple and effective method to select HLA-A(*)1101(+)K562 cells has been established and a subline of K562 cell expressing HLA-A(*)1101 protein on its cell membrane was successfully constructed, which provides the tool cells for further studying the specific cellular immunity against-CML.