
==== Front
bioRxiv
BIORXIV
bioRxiv
2692-8205
Cold Spring Harbor Laboratory

10.1101/2024.08.21.608981
preprint
1
Article
CARD8 inflammasome activation during HIV-1 cell-to-cell transmission
Kulsuptrakul Jessie
Emerman Michael
Mitchell Patrick S http://orcid.org/0000-0001-8375-9060

22 8 2024
2024.08.21.608981https://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License, which allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use.
http://biorxiv.org/lookup/doi/10.1101/2024.08.21.608981
nihpp-2024.08.21.608981.pdf
Our previous work demonstrated that CARD8 detects HIV-1 infection by sensing the enzymatic activity of the HIV protease, resulting in CARD8-dependent inflammasome activation (Kulsuptrakul et al., 2023). CARD8 recognition of HIV-1 protease activity is conferred by a HIV protease substrate mimic within the CARD8 N-terminus, which when cleaved by HIV protease triggers CARD8 inflammasome activation. Here, we sought to understand CARD8 responses to HIV-1 when the virus is transmitted through cell-to-cell infection from infected cells to target cells via a viral synapse. We observed that cell-to-cell transmission of HIV-1 induces CARD8 inflammasome activation in immortalized cells and primary human monocyte-derived macrophages in a manner that is dependent on viral protease activity and largely independent of the NLRP3 inflammasome. Additionally, to further evaluate the viral determinants of CARD8 sensing, we tested a panel of HIV protease inhibitor resistant clones to establish how variation in HIV protease affects CARD8 activation. We identified mutant HIV-1 proteases that differentially cleave and activate CARD8 compared to wildtype HIV-1, thus indicating that natural variation in HIV protease affects not only the cleavage of the viral Gag-Pol polyprotein but also likely impacts innate sensing and inflammation.
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pmc
