Nature Reviews Microbiology, Published online: 02 October 2026; doi:10.1038/s41579-026-01376-xBacteria deploy diverse immune systems to counter phage infection, yet how these systems sense invasion remains incompletely understood. This Review categorizes phage-derived triggers and outlines emerging principles that govern immune recognition of phage infection.

Cyclic oligonucleotide–based antiphage signaling systems (CBASS) are bacterial immune pathways evolutionarily related to cGAS-STING (cyclic GMP-AMP synthase–stimulator of interferon genes) in humans. ...

The conservation of immune systems from prokaryotes to eukaryotes can guide discovery of immunity genes across the tree of life. Most studies to date have focused on metazoan systems, while the extent...

Retrotransposons can infect neighboring cells using a mechanism that relies on a small fusogen-like protein rather than on the envelope protein that is typically required for infection.

CRISPR-Cas provides RNA-mediated adaptive immunity, but how its first RNA-guided effector arose is unclear. In this study, we report the discovery of Viral Interference Programmable Repeat (VIPR) syst...

The BASEL collection of phages that infect E. coli has been a valuable resource, but is limited by the peculiarities of the host strain used. This study uses a modified host to expand the collection…

Viruses are ubiquitous mobile genetic elements that are obligate symbionts of cellular life forms and replicate exclusively within host cells. The ...

Recent discoveries on bacterial immunity have revealed that several protein domains involved in anti-phage defense are conserved in eukaryotes, such as SIRim, TIR, PNP and gasdermin. Bacterial immune ...

Bacterial ribosomes can synthesize proteins encoded within their own RNA.

We treat viral antagonism as a discovery tool for host biology to reveal fundamental mechanisms of immune signaling and new opportunities for therapeutic intervention.

How functional protein sequences are distributed in sequence space is fundamentally important for evolutionary theory and protein design, particula...

The T7 bacteriophage deactivates bacterial defence systems through T7K phosphorylation of nearly all host and phage proteins during infection.

The T7 bacteriophage deactivates bacterial defence systems through T7K phosphorylation of nearly all host and phage proteins during infection.

Many bacterial immune defenses transmit recognition of phage infection via the generation of diverse cyclic nucleotide second messengers. Phage have evolved to subvert this kind of immunity by sequest...

Bacterial diadenylate cyclase (DAC) enzymes synthesize the nucleotide signal 3′3′ cyclic di-AMP (3′3′-c-di-AMP) to control osmoregulation, cell-wall homeostasis, and DNA-damage responses. Here we disc...

The Review describes shared ancient, conserved mechanisms between human antiviral immunity and bacterial anti-phage systems, outlining universal principles of pathogen sensing, signalling and effector...

Bacteria produce natural products to adapt to their environments, with phage interactions as major ecological and evolutionary drivers. While some nat…

EMBL Hamburg / CSSB The European Molecular Biology Laboratory (EMBL) is Europe’s flagship life sciences organization, with more than 110 independent research groups across Heidelberg, Hamburg, Grenobl...

Phages often degrade the genome of their bacterial host to individual nucleotides. Here we describe Metis, a bacterial defense system that directly senses phage-mediated host genome degradation. Metis...

Phages often degrade the genome of their bacterial host to individual nucleotides. Here we describe Metis, a bacterial defense system that directly senses phage-mediated host genome degradation. Metis...

Conjugative plasmids are a class of mobile genetic elements capable of efficient transfer between bacterial cells. Although they can introduce beneficial traits such as antibiotic resistance to recipi...

All kingdoms of life have developed strategies to limit viral infection. In humans, interferons induce a suite of antiviral factors that collectively provide immunity. Some human immune genes are homo...

Bacterial defense systems act as barriers to phage infection and plasmid transformation. Here, Garb et al. designed synthetic proteins that disable bacterial defense systems, enabling phages to infect...

Small molecules produced by TIR (Toll-interleukin-1 receptor) domains are essential for plant immune signaling. A central TIR-derived signal is 2'cADPR, a cyclic ADP-ribose (ADPR) molecule that is gen...

In this issue of Cell Host & Microbe, Osterman et al. discover aRES, a new family of bacterial immune proteins that deplete cellular NAD+, generating cleavage products that cannot be utilized by canon...

Folddisco enables protein structural motif search in million scale databases.