. Author manuscript; available in PMC: 2012 Nov 13.

Published in final edited form as: Nat Rev Immunol. 2010 Apr;10(4):225–235. doi: 10.1038/nri2735

Table 1.

Cytokines involved in the initiation and amplification of T_H2-type immune responses

Cytokine	Induced by	Main source	Main targets	Functions related to T_H2-type immune responses
IL-4	Antigen^12,60,61, IPSE²⁵, IgE²⁹, IL-2 (REF. 1), IL-3 (REF. 29), IL-4 (REF. 1), IL-25 (REF. 86) and TSLP^71–75	Naive CD4⁺ T cells^12,60,61, T_H2 cells¹, NKT cells⁵³ and basophils^{21,25,29,30,57–59}	T cells^6,7, B cells^107,108, macrophages¹⁰⁹ and epithelial cells^22,70	Induction of T_H2-associated cytokines^6,7, IgE class switching^107,108, alternative macrophage activation¹⁰⁹ and induction of TSLP expression^22,70
IL-2	Antigen³	Activated CD4⁺ T cells³	T cells³	Induction of IL-4 (REFS 15,16), IL-4Rα³ and IL-2Rα³ expression
TSLP	Allergens²¹, helminth-derived products²⁷, IL-4 and IL-13 (REFS 22,70)	Epithelial cells^{19,22,27,28,68–70}, basophils^21,69 and mast cells^28,69	DCs^28,45,75, T cells^71–75, basophils³⁶ and mast cells⁸¹	Suppression of IL-12 production^45,78–80 and induction of T_H2-associated cytokines ^71,72
IL-25	Allergens^19,86, helminth-derived products^84,85 and IL-4 (REF. 82)	T_H2 cells ⁸², epithelial cells^19,86, basophils⁸⁸, eosinophils⁸⁸ and mast cells⁸⁸	T cells⁸⁶ and NBNT cells^82–84	Induction of T_H2-associated cytokines^82,84,86
IL-33	Allergens¹⁹ and helminth-derived products⁹⁴	Epithelial cells^19,110, endothelial cells¹¹⁰, airway smooth muscle cells¹¹¹ and adipocytes¹¹²	T_H2 cells ^90,91,99, DCs¹¹³, basophils^95,96, mast cells⁹⁷, macrophages^98,114 and NBNT cells⁸³	Induction of T_H2-associated cytokines^{89,91,95,96,99}, TSLP expression⁹⁴ and amplification of alternatively activated macrophages⁹⁸

DC, dendritic cell; IL, interleukin; IPSE, IL-4-inducing principle of Schistosoma mansoni eggs; NBNT, non-B non-T; NKT, natural killer T; T_H2, T helper 2; TSLP, thymic stromal lymphopoietin.