NLRP3 and influenza: While NLRP3 inflammasome-mediated IL-1β release is a prominent feature of macrophages,15–17 neutrophils have also been reported to release IL-1β through the NLRP3 inflammasome pathway.18 19 The absence of IL-1β in neutrophil-depleted mice following influenza infection suggested that either neutrophils were the sole source of this cytokine or they indirectly mediate IL-1β expression and/or release in macrophages.