Human pathogenic fungus Trichophyton schoenleinii activates the NLRP3 inflammasome

The fungus Trichophyton schoenleinii(T.schoenleinii)is the causative agent of Trichophytosis and Tinea favosa of the scalp in certain regions of Eurasia and Africa.Hu-man innate immune system plays an important role in combating with various pathogens including fungi.The inflammasome is one of the most critical arms of host innate immunity,which is a protein complex controlling maturation of IL-1β.To clarify whether T.schoenleinii is able to activate the infl ammasome,we analyzed human monocytic cell line THP-1 for IL-1βproduction upon infec-tion with T.schoenleinii strain isolated from Tinea favosa patients,and rapid IL-1βsecretion from THP-1 cells was observed.Moreover,applying competitive inhibitors and gene specifi c silencing with shRNA,we found that T.sch-oenleinii induced IL-1βsecretion,ASC pyroptosome for-mation as well as caspase-1 activation were all dependent on NLRP3.Cathepsin B activity,ROS production and K+effl ux were required for the infl ammasome activation by T.schoenleinii.Our data thus reveal that the NLRP3 infl am-masome plays an important role in host defense against T.schoenleinii,and suggest that manipulating NLRP3 signaling can be a novel approach for control of diseases caused by T.schoenleinii infection.