The NLRP3 Inflammasome activation in human or mouse cells,sensitivity causes puzzle

SIGNAL 1 ALONE IS ENOUGH TO ACTIVATE THE NLRP3 INFLAMMAOSME IN HUMAN CELLS According to our current understanding,the NLR family,pyrin domain containing 3(NLRP3)infl ammasome activation is generally a two-step process.The fi rst step is priming,in which pathogen associated molecular patterns(PAMPs)such as LPS or pro-inflammatory cytokines such as tumor necrosis factor-α(TNF-α)induced NF-κB activation provides synthesis of pro-IL-1βand NLRP3 proteins.This priming step is considered as signal 1,which makes the cell ready for a second strike to assemble the infl ammasome.Then danger signals such as ATP and MSU provide the signal 2 that promotes formation of the NLRP3 infl ammasome and activates caspase-1.Both of these 2 steps are required in mouse macrophages for the NLRP3 inflammasome activation(Dinarello,2007).