Download MendeleyBacteriophages inhibit and evade cGAS-like immune function in bacteria.
Huiting, E., Cao, X., Ren, J., Athukoralage, J.S., Luo, Z., Silas, S., An, N., Carion, H., Zhou, Y., Fraser, J.S., Feng, Y., Bondy-Denomy, J.(2023) Cell 186: 864
- PubMed: 36750095
- DOI: https://doi.org/10.1016/j.cell.2022.12.041
- Primary Citation of Related Structures:
8H2J, 8H2X, 8H39 - PubMed Abstract:
A fundamental strategy of eukaryotic antiviral immunity involves the cGAS enzyme, which synthesizes 2',3'-cGAMP and activates the effector STING. Diverse bacteria contain cGAS-like enzymes that produce cyclic oligonucleotides and induce anti-phage activity, known as CBASS. However, this activity has only been demonstrated through heterologous expression. Whether bacteria harboring CBASS antagonize and co-evolve with phages is unknown. Here, we identified an endogenous cGAS-like enzyme in Pseudomonas aeruginosa that generates 3',3'-cGAMP during phage infection, signals to a phospholipase effector, and limits phage replication. In response, phages express an anti-CBASS protein ("Acb2") that forms a hexamer with three 3',3'-cGAMP molecules and reduces phospholipase activity. Acb2 also binds to molecules produced by other bacterial cGAS-like enzymes (3',3'-cUU/UA/UG/AA) and mammalian cGAS (2',3'-cGAMP), suggesting broad inhibition of cGAS-based immunity. Upon Acb2 deletion, CBASS blocks lytic phage replication and lysogenic induction, but rare phages evade CBASS through major capsid gene mutations. Altogether, we demonstrate endogenous CBASS anti-phage function and strategies of CBASS inhibition and evasion.
Organizational Affiliation:
Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA.
