Th17 cells are a subset of activated CD4+ T cells that are responsive to IL-1R1 and IL-23R signaling. They are regulated by the IL-6/STAT3/ROR gamma t lineage control. Th17 cells act as a bridge between adaptive and innate immunity where they promote neutrophil activation, immunity to pathogens, and inflammation.
Th17 cells produce the following inflammatory cytokines
- IL-26 (human)
- MIP-3 alpha
- TNF alpha
Th17 Cells Differ From Th1 and Th2 Cells
Through the study of IL-23, it was discovered that an alternate Th cell subset promotes chronic inflammation and tissue damage. Th17 cells were classified as an additional effector CD4+ T cell subset based on their independence from the transcription factors GATA3 and T-bet and the cytokines IFN gamma and IL-4, used to define Th1 and Th2, respectively.