Contribution of the IL-17/IL-23 axis to the pathogenesis of inflammatory bowel disease

Table 1 Main characteristics of CD4 T-cell subsets

CD4 T-cell subsets	Surface expression	Polarizing Cytokines	Master regulator transcription factor	STAT regulators	Effector profile/signature cytokines
Th1	IL-12RB2	IL-12,		STAT1,	IFN-γ,
	IFN-γR	IFN-γ,	T-bet	STAT4	IL-2,
	Tim3	IL-27			TNF-α,
					IL-10
Th2	IL-17RB	IL-4,
	Tim1	IL-25,	GATA-3	STAT6	IL-4, IL-5,
		IL-6	MAF		IL-13, IL-25,
					IL-2, IL-10
Th17	IL-1R1	TGF-β,	RORγt,		IL-17A,
	IL-12RB	IL-6,	RORα,		IL-17F,
	IL-23R	IL-1β,		STAT3	Il-21,
	CCR6	IL-21,			IL-22
	CD161	IL-23
	IL-13Ra1
TREG	CD25
	CD39	TGF-β	Foxp3	STAT5	TGF-β,
	CD73				IL-10
	CD101
	CD127
TFh	CD84	IL-6,	Bcl6		IL-6,
	CXCR5	IL-1β, TNFα	IRF4,		IL-2,
	IL-6R	IL-21	c-Maf,	STAT3/5	IL-10,
	IL-21R	CXCL13	Batf,		IL-21
	gp130

TFh: Follicular B helper T cells found in the B cell follicles; STAT3: Signal transducer and activator of transcription 3/5; Foxp3- forkhead box P3, a key transcription factor controlling T regulatory cell (Treg); t-bet: T-box transcription factor TBX21 which initiates Th1 lineage development from naïve Th precursor cells; GATA-3: GATA binding protein 3, an important regulator of T cell development; MAF: Proto-oncogene c-Maf or V-maf musculoaponeurotic fibrosarcoma oncogene homolog; Batf: B-cell-activating transcription factor required for the differentiation of IL-17-producing Th17 cells and T_FH cells; Bcl6- B-cell-activating transcription factor; Tim-3: T-cell immunoglobulin domain and mucin domain 3, a negative regulator of Th1-cell responses, CXC13- C-X-C motif chemokine 13.