Expression Pattern of Interferon-γ in Human Leukemic T Cell Lines Following Treatment with Phytoheamagglutinin, phorbol myristate acetate and Lipopolysaccharide

Background: As a T helper type 1 (Th1) derived cytokine, Interferon gamma (IFN-γ) is an important regulator of inflammatory immune responses. Furthermore, IFN-γ plays an essential role in defense against tumors and intracellular pathogens. This study was designed to assess the pattern of IFN-γ production in human leukemic (Jurkat and Molt-4) T cell lines in vitro. Methods: Jurkat and Molt-4 cells were cultured in whole RPMI-1640 media. The cells were imbedded at a density of 2×106 cell/ml. The cells were stimulated with different concentrations of Phytoheamagglutinin (PHA) (2-10 µg/ml), phorbol myristate acetate (PMA) (1-25 ng/ml) or lipopolysaccharide (LPS) (1-4 μg/ml) for activation and cytokine production for 48 hours. Then the cell-conditioned media were used for IFN-γ assay. Analysis of variance (ANOVA) was done for comparing the groups statistically. Results: PHA and PMA substantially augmented IFN-γ level in human leukemic T cells (Molt-4 and Jurkat) in a dose-dependent manner after 48 hours of incubation compared with untreated control cells, whereas LPS did not have any significant effect on IFN-γ production in human leukemic T cell lines compared with unstimulated cells. Conclusion: human leukemic Jurkat and Molt-4 T cell lines could potentially produce IFN-γ with different amounts. PHA was a more potent stimulator of IFN-γ production than PMA. Molt-4 cell line could produce more IFN-γ than Jurkat cell line. These cells could be appropriate for studying the mechanisms of action of immunomodulators as well as screening the IFN-γ stimulators/inhibitors.