Biology:Interleukin-12 subunit beta

Short description: Protein-coding gene in the species Homo sapiens

Generic protein structure example

Subunit beta of interleukin 12 (also known as IL-12B, natural killer cell stimulatory factor 2, cytotoxic lymphocyte maturation factor p40, or interleukin-12 subunit p40) is a protein subunit that in humans is encoded by the IL12B gene. IL-12B is a common subunit of interleukin 12 and interleukin 23.

Function

This gene encodes a subunit of interleukin 12, a cytokine that acts on T and natural killer cells, and has a broad array of biological activities. Interleukin 12 is a disulfide-linked heterodimer composed of the 40 kDa cytokine receptor like subunit encoded by this gene, and a 35 kDa subunit encoded by IL12A. This cytokine is expressed by activated macrophages that serve as an essential inducer of Th1 cells development. This cytokine has been found to be important for sustaining a sufficient number of memory/effector Th1 cells to mediate long-term protection to an intracellular pathogen. Overexpression of this gene was observed in the central nervous system of patients with multiple sclerosis (MS), suggesting a role of this cytokine in the pathogenesis of the disease. The promoter polymorphism of this gene has been reported to be associated with the severity of atopic and non-atopic asthma in children.

Role as IL-23 subunit

Interleukin-12 p40 also serves as a subunit of interleukin 23.

Further reading

• "The interleukin-12 and interleukin-12 receptor system in normal and transformed human B lymphocytes". Haematologica 87 (4): 434–42. 2002. PMID 11940489. 
• Abdi K (2002). "IL-12: the role of p40 versus p75". Scand. J. Immunol. 56 (1): 1–11. doi:10.1046/j.1365-3083.2002.01101.x. PMID 12100467. 
• "Assignment of genes encoding a unique cytokine (IL12) composed of two unrelated subunits to chromosomes 3 and 5". Genomics 14 (1): 59–62. 1992. doi:10.1016/S0888-7543(05)80283-6. PMID 1358798. 
• "Cloning of cDNA for natural killer cell stimulatory factor, a heterodimeric cytokine with multiple biologic effects on T and natural killer cells". J. Immunol. 146 (9): 3074–81. 1991. doi:10.4049/jimmunol.146.9.3074. PMID 1673147. 
• "Coexpression of two distinct genes is required to generate secreted bioactive cytotoxic lymphocyte maturation factor". Proc. Natl. Acad. Sci. U.S.A. 88 (10): 4143–7. 1991. doi:10.1073/pnas.88.10.4143. PMID 1674604. Bibcode: 1991PNAS...88.4143G. 
• "Homology of the p40 subunit of natural killer cell stimulatory factor (NKSF) with the extracellular domain of the interleukin-6 receptor". Cell 66 (1): 9–10. 1991. doi:10.1016/0092-8674(91)90131-H. PMID 2070420. 
• "Purification to homogeneity and partial characterization of cytotoxic lymphocyte maturation factor from human B-lymphoblastoid cells". Proc. Natl. Acad. Sci. U.S.A. 87 (17): 6808–12. 1990. doi:10.1073/pnas.87.17.6808. PMID 2204066. Bibcode: 1990PNAS...87.6808S. 
• "IL-12 is expressed and released by human keratinocytes and epidermoid carcinoma cell lines". J. Immunol. 153 (12): 5366–72. 1995. doi:10.4049/jimmunol.153.12.5366. PMID 7527439. 
• "Human IL-12 p40 homodimer binds to the IL-12 receptor but does not mediate biologic activity". J. Immunol. 154 (1): 116–27. 1995. doi:10.4049/jimmunol.154.1.116. PMID 7527811. 
• "Regulation of interleukin 12 p40 expression through an NF-kappa B half-site". Mol. Cell. Biol. 15 (10): 5258–67. 1995. doi:10.1128/MCB.15.10.5258. PMID 7565674. 
• "Differential expression of cytokine genes in HIV-1 tat transfected T and B cell lines". Biochem. Biophys. Res. Commun. 208 (2): 704–13. 1995. doi:10.1006/bbrc.1995.1395. PMID 7695626. 
• "High-resolution physical mapping of human 5q31-q33 using three methods: radiation hybrid mapping, interphase fluorescence in situ hybridization, and pulsed-field gel electrophoresis". Genomics 24 (2): 395–8. 1995. doi:10.1006/geno.1994.1636. PMID 7698768. 
• "Stimulatory and inhibitory effects of interleukin (IL)-4 and IL-13 on the production of cytokines by human peripheral blood mononuclear cells: priming for IL-12 and tumor necrosis factor alpha production". J. Exp. Med. 181 (2): 537–46. 1995. doi:10.1084/jem.181.2.537. PMID 7836910. 
• "Mouse interleukin-12 (IL-12) p40 homodimer: a potent IL-12 antagonist". Eur. J. Immunol. 25 (1): 200–6. 1995. doi:10.1002/eji.1830250133. PMID 7843232. 
• "IL-12 inhibits apoptosis induced in a human Th1 clone by gp120/CD4 cross-linking and CD3/TCR activation or by IL-2 deprivation". Cell. Immunol. 161 (1): 14–21. 1995. doi:10.1006/cimm.1995.1003. PMID 7867080. 
• "The interleukin 12 p40 gene promoter is primed by interferon gamma in monocytic cells". J. Exp. Med. 183 (1): 147–57. 1996. doi:10.1084/jem.183.1.147. PMID 8551218. 
• "Induction of interleukin-12 (IL-12) by recombinant glycoprotein gp120 of human immunodeficiency virus type 1 in human monocytes/macrophages: requirement of gamma interferon for IL-12 secretion". J. Virol. 70 (6): 4121–4. 1996. doi:10.1128/JVI.70.6.4121-4124.1996. PMID 8648753. 
• "Ligation of CD40 on dendritic cells triggers production of high levels of interleukin-12 and enhances T cell stimulatory capacity: T-T help via APC activation". J. Exp. Med. 184 (2): 747–52. 1996. doi:10.1084/jem.184.2.747. PMID 8760829. 
• "Local production of the p40 subunit of interleukin 12 suppresses T-helper 1-mediated immune responses and prevents allogeneic myoblast rejection". Proc. Natl. Acad. Sci. U.S.A. 93 (17): 9085–9. 1996. doi:10.1073/pnas.93.17.9085. PMID 8799158. Bibcode: 1996PNAS...93.9085K. 
• "Human immunodeficiency virus gp120 inhibits interleukin-12 secretion by human monocytes: an indirect interleukin-10-mediated effect". Blood 89 (8): 2842–8. 1997. doi:10.1182/blood.V89.8.2842. PMID 9108403.