Rapid ex vivo isolation and long-term culture of human Th17 cells

T helper (Th) 17 cells are a distinct lineage of CD4+ T cells mediating tissue inflammation through the secretion of IL-17. In addition, it has been shown that the expression of the transcriptional factor ROR gamma t is responsible for the induction and maintenance of this cell line. Th 17 cells are believed to be involved in a variety of autoimmune disorders, but may also play an important role in host defense. Here we describe a novel technique to reproducibly isolate viable Th17 cells based on their IL-17 secreting ability. We confirmed Th17 cell enrichment by quantitative PCR analysis and demonstrate that positively selected cells using this technique express significantly increased mRNA levels of ROR gamma t, IL-23 receptor and CCR4 when compared to negatively selected cells. Furthermore, we show that purified Th 17 cells can be maintained in long-term culture and expand in vitro. In conclusion, this technique will allow for the first time the direct, ex vivo analysis of phenotypic and functional properties of Th17 cells. (C) 2008 Elsevier B.V. All rights reserved.