Interleukin 32 (IL-32)

Interleukin 32 (IL-32) is a pro-inflammatory cytokine primarily expressed in immune cells and several other tissues, encoded by the *IL32* gene in humans[1][5][7]. Unlike most interleukins, IL-32 does not belong to any established cytokine family due to lack of sequence homology with other cytokines[1]. It is mainly intracellular, with at least nine isoforms generated by alternative splicing; IL-32γ is the most active and extensively studied[1][3]. IL-32 stimulates immune cells such as monocytes and macrophages to secrete other inflammatory cytokines (e.g., TNF-α, IL-6, IL-1β) and chemokines (e.g., IL-8)[1][5]. It plays roles in both innate and adaptive immune responses, can regulate osteoclast differentiation, and shows both pro- and anti-inflammatory properties depending on its isoform[3]. IL-32 expression is induced during immune cell activation and is implicated in several diseases, notably chronic inflammation, cancer, autoimmune diseases (such as rheumatoid arthritis and type 1 diabetes), infections, and cardiovascular pathology[2][4][5]. The cellular receptor for IL-32 is poorly characterized; possible interactions with integrins αVβ3 and αVβ6 have been reported, but a specific high-affinity receptor analogous to other cytokines has not been definitively established[2][4][5]. Targeting IL-32 therapeutically remains a research interest due to its broad involvement in inflammatory processes, but clinically validated drugs or detailed safety/tolerability profiles are not yet available[4][5].

Other names

Natural killer cell transcript 4 (NK4)IL32