IL-21-producing Th cells in immunity and autoimmunity.
IL-21 is a member of the common γ-chain signaling family of cytokines. Analyses of the behavior of immune cells in response to IL-21 in vitro and studies of mice deficient in IL-21 or its receptor indicate that IL-21 has a role in lymphocyte activation, proliferation, differentiation, and survival. IL-21-producing CD4(+) Th cells constitute a broad array of helper subtypes including T follicular helper cells and Th17 cells. Both autocrine and paracrine utilization of IL-21 contributes to the overall signal transduction pathways of the Ag receptor to influence the growth and survival of lymphocytes. The redundancy that IL-21 exhibits in lymphoid organs during immune responses is in stark contrast to the evidence that pharmacological neutralization of this cytokine can halt inflammation in nonlymphoid organs where IL-21 becomes the dominant voice.
Immunological Diseases Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010.
Sue M
SM
Liu
Cecile
C
King
D000818:Animals; D015551:Autoimmunity; D006801:Humans; D007378:Interleukins / Q000096:biosynthesis*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000378:metabolism; D000098546:Interleukin-21
D007378:Interleukins; D000098546:Interleukin-21