Profile of interleukin-2 production in human mononuclear cells and T-cell lines

Background and Objective: Interleukin-2 (IL-2) as a T helper type 1 (Th1) cytokine has an important role in activation, growth and differentiation of several immune cells. Moreover, IL-2 is known as a pro-inflammatory and anti-tumoral cytokine. In addition, deysregulation of IL-2 in some diseases such as autoimmunity has been shown. The present study was conducted to evaluate the patterns of IL-2 production in human peripheral blood mononuclear cells (PBMCs) and human leukemic T cells lines (Molt-4 and Jurkat). Materials and Methods: Human PBMCs and leukemic T cells were cultured in complete RPMI-1640 medium. The cells were then seeded at a density of 106 cells/ml and were incubated with different concentrations of phorbol myristate acetate (PMA) (1-25 ng/ml) or phytoheamagglutinin (PHA) (2-10 ?g/ml) for 48 hours. Then, the cell-conditioned media were collected and used for IL-2 assay. Statistical comparisons between groups were made by analysis of variance (ANOVA). Results: PHA/PMA significantly and dose-dependently increased IL-2 level in human PBMCs and leukemic T cells (Molt-4 and Jurkat) after 48 hours of incubation compared with untreated control cells. Conclusion: We conclude that human PBMCs and leukemic T cells (Jurkat and Molt-4) could potentially secrete IL-2 with different degrees. Thus, these cells could offer a proper system to study the mechanisms regulating IL-2 production in diseases in which IL-2 production is disregulated. Also, these cells could be useful for screening the IL-2 modulators.