Il21

Function

Cytokine with immunoregulatory activity. May promote the transition between innate and adaptive immunity. Induces the production of IgG(1) and IgG(3) in B-cells (PubMed:15100251). Implicated in the generation and maintenance of T follicular helper (Tfh) cells and the formation of germinal-centers. Together with IL6, control the early generation of Tfh cells and are critical for an effective antibody response to acute viral infection (PubMed:23045607). May play a role in proliferation and maturation of natural killer (NK) cells in synergy with IL15 (PubMed:11970879). May regulate proliferation of mature B- and T-cells in response to activating stimuli. In synergy with IL15 and IL18 stimulates interferon gamma production in T-cells and NK cells (By similarity). During T-cell mediated immune response may inhibit dendritic cells (DC) activation and maturation (PubMed:12893770).

Sequence Similarities

Belongs to the IL-15/IL-21 family.

Tissue Specificity

Expressed in CD4(+) T cells.

Cellular localization

• Secreted

Alternative names

Interleukin-21, IL-21, Il21

Database links

swissprot:Q9ES17 entrezGene:60505

Other research areas

• Immuno-oncology