Plasma membrane damage causes NLRP3 activation and pyroptosis during Mycobacterium tuberculosis infection

Mycobacterium tuberculosis (Mtb) is a major global health problem and causes extensive cytotoxicity in patient cells and tissues. Here we define an NLRP3, caspase-1 and gasdermin D-mediated pathway to pyroptosis in human monocytes following exposure to Mtb. We demonstrate an ESX-1 mediated, contact-induced plasma membrane (PM) damage response that occurs during phagocytosis or from the cytosolic side of the PM after phagosomal rupture in Mtb infected cells. This PM injury in turn causes K+ efflux and activation of NLRP3 dependent IL-1{beta} release and pyroptosis, facilitating the spread of Mtb to neighbouring cells. Further we reveal a dynamic interplay of pyroptosis with ESCRT-mediated PM repair. Collectively, these findings reveal a novel mechanism for pyroptosis and spread of infection acting through dual PM disturbances both during and after phagocytosis. We also highlight dual PM damage as a common mechanism utilized by other NLRP3 activators that have previously been shown to act through lysosomal damage.\n\nGraphical abstract\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=115 SRC=\"FIGDIR/small/747014v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (28K):\norg.highwire.dtl.DTLVardef@1911356org.highwire.dtl.DTLVardef@18c99dcorg.highwire.dtl.DTLVardef@1c94bb9org.highwire.dtl.DTLVardef@8a69db_HPS_FORMAT_FIGEXP M_FIG C_FIG