In vitro human TGF-beta treatment converts CD4(+)CD25(-) T cells into induced T regulatory like cells

Abstract

In mammals, induced T regulatory cells (iTregs) are produced by treating CD4(+)CD25(-) cells in vitro with TGF-beta in the presence of anti-CD3 and IL-2. Chicken CD4(+)CD25(-) cells were treated in vitro with TGF-beta, anti-CD3, anti-CD28 and IL-2 and analyzed for suppressive properties, IL-10 and IL-2 mRNA amounts. TGF-beta treatment decreased (P<0.01) CD4(+)CD25(-) cell proliferation by 45% at 5d of cell culture with no increase in dead cell population. CD4(+)CD25(-) cells treated with 5ng TGF-beta for 5d had 130-fold (P<0.01) more IL-10 and 104-fold (P<0.01) less IL-2 mRNA content than the 0ng TGF-beta treated groups. CD4(+)CD25(-) cells treated with 5ng TGF-beta for 5d suppressed (P<0.01) naïve cell proliferation compared to the 0ng TGF-beta treated groups. The results suggest the presence of iTreg-like cells in avian species.