Full name: Interleukin-2

Aliases:1 TCGF and lymphokine

Size:2,3 15.5–16.0 kDa

Family:3 IL-2 family (IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21)

Receptors:3 IL-2 receptor

Major cellular sources:2-4 Activated CD4+ and CD8+ T cells, naïve T cells, NK cells, NKT cells, DCs, and mast cells

Major cellular targets:3 CD4+ and CD8+ T cells, B cells, NK cells, and ILCs

Disease states associated with:2,5 Immune diseases, inflammation, autoimmune diseases, inflammatory bowel disease, and allograft rejection

Major physiologic functions:

  • IL-2 plays a key role in immune responses.5

  • Members of the IL-2 family bind to a shared gamma chain receptor, function primarily as growth and proliferation factors for progenitors, and mature cells and have roles in lineage-specific cell differentiation.3

  • IL-2 is essential for the development, differentiation, and maintenance of Treg cells.5,6

  • IL-2 functions as a B-cell growth factor and stimulates antibody synthesis.3

  • IL-2 promotes the proliferation and differentiation of NK cells, including increased cytolytic functions.3

  • IL-2 limits inflammation by inhibiting Th17-cell differentiation.5

  • IL-2 promotes the development of Tfh cells, a subset of T cells that controls humoral immune responses.5

CD: cluster of differentiation; DC: dendritic cell; IL: interleukin; ILC: innate lymphoid cell; NK: natural killer; NKT: natural killer T; TCGF: T-cell growth factor; Tfh: T follicular helper; Th: T helper; Treg: regulatory T.


  • 1.

    NCBI. Gene. IL2 interleukin 2 [Homo sapiens (human)]. Accessed March 11, 2021.

  • 2.

    Arenas-Ramirez N, Woytschak J, Boyman O. Trends Immunol. 2015;36:763-777.

  • 3.

    Akdis M, Aab A, Altunbulakli C, et al. J Allergy Clin Immunol. 2016;138:984-1010.

  • 4.

    Nelson BH. J Immunol. 2004;172:3983-3988.

  • 5.

    Banchereau J, Pascual V, O'Garra A. Nat Immunol. 2012;13:925-931.

  • 6.

    Gaffen SL, Liu KD. Cytokine. 2004;28:109-123.