Analysis of IL-17 production by flow cytometry and ELISPOT assays.

Interleukin (IL)-17 represents a family of cytokines with six members, namely IL-17A, B, C, D, E, and F. IL-17A and IL-17F are best studied proinflammatory cytokines. CD4(+) T helper cells producing IL-17A have been identified as a distinct T helper subset, Th17 cells. IL-17 and Th17 cells are important mediators in tissue inflammation in immune-mediated inflammatory diseases. IL-17 is also produced by other immune cells and plays an important role in host defense against microbial infection. Cell-based assays are sensitive and quantitative, and enable identification of cellular sources of IL-17 production. This chapter describes usage of flow cytometry and ELISPOT assays to quantify IL-17A-producing cells in disease and in vitro experiments to study T cell function.