[HTML][HTML] The inflammasome mediates UVB-induced activation and secretion of interleukin-1β by keratinocytes

L Feldmeyer, M Keller, G Niklaus, D Hohl, S Werner… - Current Biology, 2007 - cell.com
L Feldmeyer, M Keller, G Niklaus, D Hohl, S Werner, HD Beer
Current Biology, 2007cell.com
It has long been known that human keratinocytes are a potent source of the proinflammatory
cytokines proIL-1α and-1β [1], which are activated and released in response to UV
irradiation [2]. However, the intracellular pathways, which regulate maturation and secretion
of IL-1 in keratinocytes, are unknown. Here we show that the UVB-mediated enhancement of
cytoplasmic Ca 2+ is required for activation of the IL-1β-converting enzyme caspase-1 by the
inflammasome, a multiprotein innate immune complex [3, 4]. Caspase-1 in turn activates …
Summary
It has long been known that human keratinocytes are a potent source of the proinflammatory cytokines proIL-1α and -1β [1], which are activated and released in response to UV irradiation [2]. However, the intracellular pathways, which regulate maturation and secretion of IL-1 in keratinocytes, are unknown. Here we show that the UVB-mediated enhancement of cytoplasmic Ca2+ is required for activation of the IL-1β-converting enzyme caspase-1 by the inflammasome, a multiprotein innate immune complex [3, 4]. Caspase-1 in turn activates proIL-1β, and keratinocytes secrete the cytokine as well as inflammasome components. These results demonstrate the presence of a proIL-1β-processing inflammasome in nonprofessional immune cells and the necessity of inflammasome components for the UVB-induced secretion of IL-1β. This supports the concept that keratinocytes are important immuno-competent cells under physiological and pathological conditions [5].
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