Human CD4+ Th-17 cells produce inflammatory cytokines and have been implicated in the development of several inflammatory pathologies. The transcription factor RORgammaT is though to establish Th-17 cell differentiation. Expression of IL-17A is a hallmark of Th-17 cells.
We have used RORgammaT overexpression as an approach to identify factors that induce Th-17 cell differentiation. This led us to the observation that TGF-beta is essential for induction of RORgammaT. However, unknown factors present in serum inhibit Th-17 cell differentiation. Thus, it is important to cultivate cells in serum-free conditions in order to generate Th-17 cells from naive CD4+ T cells. In serum-free conditions, we found that a combination of TGF-beta, IL-1beta and either IL-6, IL-21 or IL-23 is able to induce Th-17 cell differentiation.
Here is described a procedure to generate human Th-17 cells from naive CD4+ T cells isolated from adult or cord blood.