biostudies-literatureKulsuptrakul JNational Institute of Allergy and Infectious DiseasesNIDA NIH HHSNIAID NIH HHSEdward Mallinckrodt Jr. FoundationNational Institute on Drug AbuseNational Institute of General Medical SciencesNIGMS NIH HHSe84108https://www.ebi.ac.uk/biostudies/studies/S-EPMC10359095biostudies-literatureUnknown12Inflammasomes are cytosolic innate immune complexes that assemble upon detection of diverse pathogen-associated cues and play a critical role in host defense and inflammatory pathogenesis. Here, we find that the human inflammasome-forming sensor CARD8 senses HIV-1 infection via site-specific cleavage of the CARD8 N-terminus by the HIV protease (HIV-1^PR). HIV-1^PR cleavage of CARD8 induces pyroptotic cell death and the release of pro-inflammatory cytokines from infected cells, processes regulated by Toll-like receptor stimulation prior to viral infection. In acutely infected cells, CARD8 senses the activity of both de novo translated HIV-1^PR and packaged HIV-1^PR that is released from the incoming virion. Moreover, our evolutionary analyses reveal that the HIV-1^PR cleavage site in human CARD8 arose after the divergence of chimpanzees and humans. Although chimpanzee CARD8 does not recognize proteases from HIV or simian immunodeficiency viruses from chimpanzees (SIVcpz), SIVcpz does cleave human CARD8, suggesting that SIVcpz was poised to activate the human CARD8 inflammasome prior to its cross-species transmission into humans. Our findings suggest a unique role for CARD8 inflammasome activation in response to lentiviral infection of humans.eLifeA human-specific motif facilitates CARD8 inflammasome activation after HIV-1 infection.PMC10359095DP2 AI154432T32 GM136534DP2 AI 154432-01T32 GM007270DP1 DA051110Turcotte EAKulsuptrakul JEmerman MMitchell PSfalseA human-specific motif facilitates CARD8 inflammasome activation after HIV-1 infection.Inflammasomes are cytosolic innate immune complexes that assemble upon detection of diverse pathogen-associated cues and play a critical role in host defense and inflammatory pathogenesis. Here, we find that the human inflammasome-forming sensor CARD8 senses HIV-1 infection via site-specific cleavage of the CARD8 N-terminus by the HIV protease (HIV-1^PR). HIV-1^PR cleavage of CARD8 induces pyroptotic cell death and the release of pro-inflammatory cytokines from infected cells, processes regulated by Toll-like receptor stimulation prior to viral infection. In acutely infected cells, CARD8 senses the activity of both de novo translated HIV-1^PR and packaged HIV-1^PR that is released from the incoming virion. Moreover, our evolutionary analyses reveal that the HIV-1^PR cleavage site in human CARD8 arose after the divergence of chimpanzees and humans. Although chimpanzee CARD8 does not recognize proteases from HIV or simian immunodeficiency viruses from chimpanzees (SIVcpz), SIVcpz does cleave human CARD8, suggesting that SIVcpz was poised to activate the human CARD8 inflammasome prior to its cross-species transmission into humans. Our findings suggest a unique role for CARD8 inflammasome activation in response to lentiviral infection of humans.2023-01-01T00:00:00Z2023 Jul2024-11-06T10:36:18.612Z2024-11-06T10:36:18.612ZS-EPMC103590953741786810.7554/eLife.84108