PT - JOURNAL ARTICLE AU - Elisabet Bjanes AU - Reyna Garcia Sillas AU - Rina Matsuda AU - Benjamin Demarco AU - Timothée Fettrelet AU - Alexandra A. DeLaney AU - Eric M. Rodriguez Lopez AU - Daniel Grubaugh AU - Meghan A. Wynosky-Dolfi AU - Naomi H. Philip AU - Elise Krespan AU - Dorothy Tovar AU - Leonel Joannas AU - Daniel P. Beiting AU - Jorge Henao-Mejia AU - Brian C. Schaefer AU - Kaiwen W. Chen AU - Petr Broz AU - Igor E. Brodsky TI - The <em>Card19</em> locus of murine chromosome 13 regulates terminal cell lysis downstream of caspase activation and Gasdermin-D cleavage AID - 10.1101/2021.03.19.436207 DP - 2021 Jan 01 TA - bioRxiv PG - 2021.03.19.436207 4099 - http://biorxiv.org/content/early/2021/03/22/2021.03.19.436207.short 4100 - http://biorxiv.org/content/early/2021/03/22/2021.03.19.436207.full AB - Cell death plays a critical role in inflammatory responses. During pyroptosis, inflammatory caspases cleave Gasdermin D (GSDMD) to release an N-terminal fragment that generates plasma membrane pores that mediate cell lysis and IL-1 cytokine release. Terminal cell lysis and IL-1β release following caspase activation can be uncoupled in certain cell types or in response to particular stimuli, a state termed hyperactivation. However, the factors and mechanisms that regulate terminal cell lysis downstream of GSDMD cleavage remain poorly understood. In the course of studies to define regulation of pyroptosis during Yersinia infection, we identified a line of Card19-/- mice whose macrophages were protected from cell death and showed reduced pore formation during apoptosis or pyroptosis, yet had wild-type levels of caspase activation, IL-1 secretion, and GSDMD cleavage. Unexpectedly, CARD19, a mitochondrial CARD-containing protein, was not directly responsible for this, as two independently-generated CRISPR/Cas9 Card19 knockout mice showed no defect in macrophage cell lysis. The original Card19-/- line was generated in a 129SvEvBrd background, and SNP analysis revealed a six megabase region of 129 origin co-segregating with the Card19 locus. Card19 is located on chromosome 13, adjacent to Ninj1, which was recently reported to regulate cell lysis downstream of GSDMD activation. Nonetheless, we could not detect major defects in NINJ1 protein expression or mutations in Ninj1 coding sequence in Card19-/- mice. Mice from the original Card19-/- line exhibited significantly increased susceptibility to Yersinia infection, demonstrating that cell lysis itself plays a key role in protection against bacterial infection. Our findings identify a locus on murine chromosome 13 that regulates the ability of macrophages to undergo plasma membrane rupture downstream of gasdermin cleavage, and implicates additional NINJ1-independent factors that control terminal cell lysis.Author Summary Programmed cell death is critical for regulating tissue homeostasis and host defense against infection. Pyroptosis is an inflammatory form of programmed cell death that couples cell lysis with release of inflammatory cytokines. Cell lysis is triggered by activation of particular intracellular pore forming proteins, but how regulation of cell lysis occurs is not well understood. We identified the Card19 locus on chromosome 13 as playing a key role in regulating terminal cell death in response to danger signals, such as bacterial infections or harmful chemicals. We found that immune cells from Card19-/- mice were resistant to multiple forms of cell death in response to a variety of harmful stimuli, including bacterial infections. Card19-/- mice were more susceptible to Yersinia infection, indicating that cell lysis contributes to control of bacterial infections. Our data provide new insight into the impact of terminal cell lysis on control of bacterial infection and indicate that additional factors exist that regulate lytic cell death.Competing Interest StatementThe authors have declared no competing interest.