Down-regulation of MHC Expression in Human Stem Cells by Introduction of hCMV US Genes / 대한이식학회지

ABSTRACT

PURPOSE: Stem cells are considered promising candidates for cell replacement therapy in many devastating diseases. However, it is assumed that stem cells may be rejected on transplantation. Therefore, we introduced human cytomegalovirus (hCMV) US genes, which are known to be able to reduce MHC class I expression on the cell surface after infection, into two known stem cell lines in order to test the feasibility of modifying these cells to reduced MHC class I antigens by the introduction of hCMV US genes. METHODS: The MHC class I expressions of mock-transfected or hCMV US gene-transfected human embryonic neural stem cell line (HB1.F3) and human breast epithelial stem cell line (M13SV1) were examined by FACS. RESULTS: MHC class I expressions in HB1.F3 and M13SV1 cells were dramatically induced by IFN-gamma treatment. In FACS analysis, cells transfected with the hCMV US2, 3, 6 or 11 genes exhibited a dramatic reduction (40~60%) of MHC class I expression compared with mock-transfected cells. CONCLUSION: Our results suggest that human stem cells express high levels of MHC class I antigens, and thus may be rejected on transplantation unless they are odified. In addition introduction of hCMV US genes can be exploited for stemcell transplantation.