Expression of Human Interferon-Gamma Gene in Human Tissue Culture Cells

ABSTRACTInterferon-gamma is a cytokine secreted by natural killer cells, CD4 TH1 cells and CD8 cytotoxic lymphocytes in response to mitogenic and antigenic stimuli. It is endowed with multiple biological activities and because of that is one of the first targets of recombinant DNA technology. Human interferon-gamma (hIFNγ) is expressed so far in Escherichia coli and various eukaryotic hosts. The disadvantages of the bacterial hIFNγ and unsatisfactory results from the eukaryotic expression were the reason to employ transient expression of the hIFNγ gene in CAP-T and HEKF cells, widely used for industrial production of human proteins. The obtained results demonstrated that (unlike with other human genes): i) cell viability decreased very fast and reached the critical level of 50% after five days only; ii) cell density did not exceed 0.7x105 cells/mL and sharply decreased after four days of cultivation; iii) the yield of hIFNy secreted in the supernatant did not exceed 5.8 mg/L.