Human T-helper (Th) cell subtypes

TypeCo-stimulatory cytokineTranscription factorsEffector cytokinesTarget
Th1IL-12T-bet, STAT1IFN-γ, TNF, IL-2Intracellular bacteria, viruses and mycobacteria
Th2IL-4STAT6, GATA3IL-4, IL-5, IL-13Extracellular parasites
Th17IL-23STAT3, RORγtIL-17A, IL-17F, IL-21, IL-22Extracellular bacteria and fungi

IL: interleukin; STAT: signal transducer and activator of transcription; IFN: interferon; TNF; tumour necrosis factor; RORγt: retinoic acid receptor-related orphan receptor γt.