Enhanced expression of HLA class I molecules in human hepatocellular carcinoma cells transduced with gamma-interferon gene.
OBJECTIVE
To investigate the expression of exogenous gamma-interferon gene in human hepatocellular carcinoma cells following retroviral transduction and the effect on the expression of surface HLA class I molecules.


METHODS
Retroviral vector pLXSN was used to introduce human gamma-interferon (IFN-gamma) gene into four different human hepatocellular carcinoma cell lines (HCC). The G418-resistant colonies were isolated and cloned. The integration and expression of IFN-gamma gene were determined by PCR and RT-PCR analysis. A bioassay method was used to test the amount of IFN-gamma secreted by gene modified HCC cells. The expression of HLA class I molecules in HCC cells were analyzed by flow cytometry using indirect fluorescence staining.


RESULTS
Four different HCC cell lines were successfully transduced with human IFN-gamma gene using retroviral vector. The integration and expression of IFN-gamma gene were shown only in the transduced cells. All four genetically modified HCC cells can secrete varied amount of IFN-gamma and demonstrate a significant up-regulation of surface HLA class I antigens. One specific HLA class I antigen, HLA-A2, has almost the same degree of increase as that of the total HLA class I molecules after transduction with IFN-gamma gene.


CONCLUSIONS
Gene modification with IFN-gamma gene can significantly enhance the expression of HLA class I molecules in HCC cells and may increase its immunogenicity. These gene modified tumor vaccines can be helpful in tumor biotherapy.
Qian
S
S
Department of Biochemistry and Molecular Biology, Shanghai Second Medical University, China.
Zhang
T
T
Chen
S
S
D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D018014:Gene Transfer Techniques; D005805:Genes, MHC Class I / Q000235:genetics; D015788:HLA-A1 Antigen / Q000096:biosynthesis* / Q000276:immunology; D015789:HLA-A2 Antigen / Q000096:biosynthesis / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics*; D008113:Liver Neoplasms / Q000235:genetics*; D014161:Transduction, Genetic; D014407:Tumor Cells, Cultured
D015788:HLA-A1 Antigen; D015789:HLA-A2 Antigen; D007371:Interferon-gamma