Interleukin 1 beta (IL1β) also known as leukocytic pyrogen, leukocytic endogenous mediator, mononuclear cell factor, lymphocyte activating factor and other names, is a cytokineprotein that in humans is encoded by the IL1Bgene. There are two genes for interleukin-1 (IL-1): IL-1 alpha and IL-1 beta (this gene). IL-1β precursor is cleaved by cytosolic caspase 1 (interleukin 1 beta convertase) to form mature IL-1β.
The fever-producing property of human leukocytic pyrogen (interleukin 1) was purified by Dinarello in 1977 (PNAS) with a specific activity of 10–20 nanograms/kg. In 1979, Dinarello reported that purified human leukocytic pyrogen was the same molecule that was described by Igal Gery in 1972. He named it lymphocyte-activating factor (LAF) because it was a lymphocyte mitogen. It was not until 1984 that interleukin 1 was discovered to consist of two distinct proteins, now called interleukin-1 alpha and interleukin-1 beta.
IL-1β is a member of the interleukin 1 family of cytokines. This cytokine is produced by activated macrophages as a proprotein, which is proteolytically processed to its active form by caspase 1 (CASP1/ICE). This cytokine is an important mediator of the inflammatory response, and is involved in a variety of cellular activities, including cell proliferation, differentiation, and apoptosis. The induction of cyclooxygenase-2 (PTGS2/COX2) by this cytokine in the central nervous system (CNS) is found to contribute to inflammatory pain hypersensitivity. This gene and eight other interleukin 1 family genes form a cytokine gene cluster on chromosome 2.
Increased production of IL-1β causes a number of different autoinflammatory syndromes, most notably the monogenic conditions referred to as CAPS, due to mutations in the inflammasome receptor NLRP3 which triggers processing of IL-1B.
Because many authors of scientific manuscripts make the minor error of using a homoglyph, sharp s (ß), instead of beta (β), mentions of "IL-1ß" [sic] often become "IL-1ss" [sic] upon automated transcoding (because ß transcodes to ss). This is why so many mentions of the latter appear in web search results.
^ ab"Catabolin" is the name given by Jeremy Saklatvala for IL-1 alpha. March CJ, Mosley B, Larsen A, Cerretti DP, Braedt G, Price V, Gillis S, Henney CS, Kronheim SR, Grabstein K (1985). "Cloning, sequence and expression of two distinct human interleukin-1 complementary DNAs". Nature. 315 (6021): 641–7. PMID2989698. doi:10.1038/315641a0.
^Gery I, Handschumacher RE (1974). "Potentiation of the T lymphocyte response to mitogens. III. Properties of the mediator(s) from adherent cells". Cell. Immunol. 11 (1–3): 162–9. PMID4549027. doi:10.1016/0008-8749(74)90016-1.
Smirnova MG, Kiselev SL, Gnuchev NV, Birchall JP, Pearson JP (2003). "Role of the pro-inflammatory cytokines tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6 and interleukin-8 in the pathogenesis of the otitis media with effusion". Eur. Cytokine Netw. 13 (2): 161–72. PMID12101072.
Griffin WS, Mrak RE (2002). "Interleukin-1 in the genesis and progression of and risk for development of neuronal degeneration in Alzheimer's disease". J. Leukoc. Biol. 72 (2): 233–8. PMID12149413.
Chakravorty M, Ghosh A, Choudhury A, Santra A, Hembrum J, Roychoudhury S (2004). "Ethnic differences in allele distribution for the IL8 and IL1B genes in populations from eastern India". Hum. Biol. 76 (1): 153–9. PMID15222686. doi:10.1353/hub.2004.0016.
Maruyama Y, Stenvinkel P, Lindholm B (2005). "Role of interleukin-1beta in the development of malnutrition in chronic renal failure patients". Blood Purif. 23 (4): 275–81. PMID15925866. doi:10.1159/000086012.
Roy D, Sarkar S, Felty Q (2006). "Levels of IL-1 beta control stimulatory/inhibitory growth of cancer cells". Front. Biosci. 11: 889–98. PMID16146780. doi:10.2741/1845.