Gene transduction of tristetraprolin or its active domain reduces TNF-α production by Jurkat T cells

Tristetraprolin (TTP) is a physiological regulator of tumor necrosis factor (TNF)-a production. It destabilizes TNF-a mRNA by binding to the AU-rich element located in the 3' region of TNF-a mRNA. We wished to determine how transducing the TTP gene or its fragment gene encoding its biological active site, the tandem zinc finger (TZF) domain, affects TNF-a production, cell viability and growth of Jurkat T cells. Jurkat T cells were transduced with either the TTP or the TZF gene using retrovirus vectors. Cell growth and apoptosis was analyzed. Expression of genes before or after appropriate stimuli was measured by real-time PCR. In addition, production of the TNF-a protein was measured by enzyme immunoassay. The transduction of either gene reduced TNF-a mRNA levels under unstimulated conditions, and reduced the response to phytohemagglutinin stimulation. Production of TNF-a protein upon stimulation was also decreased in TTP/TZF-transduced cells. Transduction of either gene also affected the expression of granulocyte-macrophage colony-stimulating factor mRNA in a similar fashion, but not that of c-myc. The growth rate of TTP-transduced Jurkat T cells tended to be slower than that of TZF- or mock-transduced cells. TTP-transduced cells were more susceptible to campthothecin-induced apoptosis than others. Our results indicate that either TTP or TZF gene transduction using retrovirus vectors can reduce the production of TNF-a in Jurkat T cells although some differences were noted between TTP and TZF in cell growth and occurrence of apoptosis. These results suggest that TTP may be a potential target for new therapies against RA.