NLRP1 Is the Key Inflammasome in Primary Human Keratinocytes.

The epidermis is the primary area of contact between the body and the environment, and it distinguishes between harmful exposures and those that should be tolerated. Discrimination between insults, and in particular the recognition of danger signals such as UVB, is mediated by innate immune receptors. Inflammasomes are one major innate mechanism that activate inflammatory caspases. In human keratinocytes, the importance of inflammasomes and the sensing of UVB and other danger signals are a matter of debate. Fenini et al. now provide evidence that the NLRP1 (rather than the NLRP3) inflammasome plays a key role in UVB sensing and subsequent IL-1β and -18 secretion by human keratinocytes.