Interleukin 27 (IL-27) is a member of the IL-12 cytokine family. It is a heterodimeric cytokine that is encoded by two distinct genes, Epstein-Barr virus-induced gene 3 (EBI3) and IL-27p28. IL-27 is expressed by antigen presenting cells and interacts with a specific cell-surface receptor complex known as IL-27 receptor (IL-27R).[1][2][3][4][5] This receptor consists of two proteins, IL-27Rɑ and gp130. IL-27 induces differentiation of the diverse populations of T cells in the immune system and also upregulates IL-10.

Signal transduction

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When IL-27 binds to the IL-27 receptor, signaling pathways including JAK-STAT and p38 MAPK pathways are turned on.[6][2] There are two types of responses, pro-inflammatory and anti-inflammatory, which involve different types of cells, such as macrophages, dendritic cells, T cells, and B cells.[3] The response that is activated is very much dependent on the external surrounding of IL-27.[1][2][3]

Differentiation of T cells

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There are many different subsets of T cells, such as Th1, Th2, Th17, Tr1, and Treg cells; IL-27 is greatly involved in differentiation through inducing or suppressing of each T cell subset.[1][2][4][5] Th1 cells, which express IFNγ, are generated by IL-27 through STAT1 dimerization and nuclear localization which subsequently leads to the expression of T-bet and signature Th1 genes. Th2 cells, which express IL-4, are inhibited by IL-27 through the transcription factor GATA-3. Th17 cells, which express IL-17, IL-22, and granulocyte macrophage colony-stimulating factor (GM-CSF), are inhibited by IL-27 through STAT1 and expression of transcription factor RORγt. Tr1 cells, which express IL-10, are induced by IL-27 through the transcription factor c-Maf. Treg cells are inhibited by IL-27 through STAT1 and STAT3.[2][4][5]

IL-10 production

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IL-10 acts in an anti-inflammatory manner by suppressing inflammatory responses.[7] One way that IL-27 can have an anti-inflammatory response is through the expression of IL-10. IL-27 has been found to be involved in the production of IL-10 by stimulating the various subsets of T cells, especially Tr1 cells. Also involved are the STAT1 and STAT3 transcription factors that bind specifically to the receptor subunits, IL-27ɑ and glycoprotein. IL-27 is able to activate STAT3 signaling, which eventually leads to an increase of IL-10 secretion from Treg cells.[1]

References

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  1. ^ a b c d Yoshida H, Hunter CA (April 2015). "The immunobiology of interleukin-27". Annual Review of Immunology. 33 (1): 417–43. doi:10.1146/annurev-immunol-032414-112134. PMID 25861977.
  2. ^ a b c d e Meka RR, Venkatesha SH, Dudics S, Acharya B, Moudgil KD (December 2015). "IL-27-induced modulation of autoimmunity and its therapeutic potential". Autoimmunity Reviews. 14 (12): 1131–1141. doi:10.1016/j.autrev.2015.08.001. PMC 4628569. PMID 26253381.
  3. ^ a b c Yoshimoto T, Chiba Y, Furusawa J, Xu M, Tsunoda R, Higuchi K, Mizoguchi I (September 2015). "Potential clinical application of interleukin-27 as an antitumor agent". Cancer Science. 106 (9): 1103–10. doi:10.1111/cas.12731. PMC 4582978. PMID 26132605.
  4. ^ a b c Iwasaki Y, Fujio K, Okamura T, Yamamoto K (January 2015). "Interleukin-27 in T cell immunity". International Journal of Molecular Sciences. 16 (2): 2851–63. doi:10.3390/ijms16022851. PMC 4346869. PMID 25633106.
  5. ^ a b c Aparicio-Siegmund S, Garbers C (October 2015). "The biology of interleukin-27 reveals unique pro- and anti-inflammatory functions in immunity". Cytokine & Growth Factor Reviews. 26 (5): 579–86. doi:10.1016/j.cytogfr.2015.07.008. PMID 26195434.
  6. ^ Sharma G, Dutta RK, Khan MA, Ishaq M, Sharma K, Malhotra H, Majumdar S (October 2014). "IL-27 inhibits IFN-γ induced autophagy by concomitant induction of JAK/PI3 K/Akt/mTOR cascade and up-regulation of Mcl-1 in Mycobacterium tuberculosis H37Rv infected macrophages". The International Journal of Biochemistry & Cell Biology. 55: 335–47. doi:10.1016/j.biocel.2014.08.022. PMID 25194337.
  7. ^ Iyer SS, Cheng G (2012-01-01). "Role of interleukin 10 transcriptional regulation in inflammation and autoimmune disease". Critical Reviews in Immunology. 32 (1): 23–63. doi:10.1615/CritRevImmunol.v32.i1.30. PMC 3410706. PMID 22428854.