The Effect of IL-22 and IL-28 in Induction of Type 1 Regulatory T (Tr1) Cells

Cytokines have been introduced as critical inducers in the development of Th subpopulations.Cytokines like IL-10 are involved in inducing regulatory T cells such as Type 1 regulatory T (Tr1) cells cells. IL-22 is a member of IL-10 family of cytokines, and IL-28A is a member of IFN-γ family. In this study, cord blood mononuclear cells (CBMC) from normal healthy individuals were isolated by Ficoll and then naïve T cells were purified by CD4+CD25+ Regulatory T cell Isolation kit. The effect of these two cytokines on production of IL-5, TGF-β, IL-10, IL-4 and IFN-γ cytokines from cord blood T cells was investigated to identify Tr1 cells as well as Th1 and Th2 polarization. Flow cytometric analysis showed that IL-28A and IL-22 were not effective in expression of IL-5 and TGF-β either alone or in synergy, but in view of IL-10, IL-4 and IFN-γ, the results showed that IL-22 increased IL-10 and IL-4 but had a decreasing effect on IFN-γ. The results showed that IL-28A was not effective in increasing or decreasing the level of IL-10, IL-4 and IFN-γ. Therefore, according to these results, IL-22 and IL-28A were not effective in inducing Tr1 cells.