IL-17-producing gammadelta T cells.

IL-17 is produced not only by CD4(+) alphabeta T cells, but also CD8(+) alphabeta T cells, NKT cells, and gammadelta T cells, plus some non-T cells, including macrophages and neutrophils. The ability of IL-17 to deploy neutrophils to sites of inflammation imparts this cytokine with a key role in diseases of several types. Surprisingly, gammadelta T cells are responsible for much of the IL-17 produced in several disease models, particularly early on.