Osterman Ilya

Antiviral Defence is a Conserved Function of Diverse DNA Glycosylases Bacteria are frequently attacked by viruses, known as phages, and rely on diverse defence systems like restriction endonucleases and CRISPR-Cas to survive. While phages can evade these defences by cov...

Excited to share: DNA glycosylases are diverse antiviral effectors. They recognize phage base modifications and initiate genome destruction. A structure‑guided approach made the scope of this discovery possible! 🧪 #phagesky doi.org/10.1101/2025... #phage #microbiology

Are you interested in studying RNA phages? We are looking for a PhD student and a postdoc to join the lab!

For more information and how to apply, see below 👇

Please RT!

Use antisense oligomers to silence phage genes and discover new biology.
@jorg-vogel-lab.bsky.social @helmholtz-hiri.bsky.social @helmholtzhzi.bsky.social @uni-wuerzburg.de
print: www.nature.com/articles/s41...
highlight: www.nature.com/articles/s41...
briefing: www.nature.com/articles/d41...

q.e.d Science Critical Thinking AI for constructive criticism and science evaluation

Here's the link to the system, try it! qedscience.com
@qedscience.bsky.social

Bacterial TIR-based immune systems sense phage capsids to initiate defense - Nature Microbiology After sensing capsids, the Thoeris antiphage defense system triggers a cascade that leads to NAD+ cleavage and cell arrest, which are dynamics that are mirrored in some mammalian immune pathways.

www.nature.com/articles/s41...

#phagesky #phage defence system Thoeris

Phages with a broad host range are common across ecosystems - Nature Microbiology Proximity-ligation-based sequencing from 111 samples and 5 environments reveals that a substantial proportion of phages infect multiple species.

www.nature.com/articles/s41...

#phagesky #phage genomics on host range

Serine recombinases are conserved genetic markers of antiphage defense systems https://www.biorxiv.org/content/10.1101/2025.10.07.681051v1

Pseudouridine RNA avoids immune detection through impaired endolysosomal processing and TLR engagement Recognition of exogenous RNA by Toll-like receptors (TLRs) is central to pathogen defense. Using two distinct binding pockets, TLR7 and TLR8 recognize…

#WeekendRead! #ToSenseOrNotToSense! #MysterySolved! Berouti, Wagner, Carell, @v-hornung.bsky.social &co show @cp-cell.bsky.social that RNase T2 & PLDs generate #TLR7 & #TLR8 agonistic ligands only if RNA does not contains pseudouridines explaining avoidance of self RNA sensing!

Antiviral reverse transcriptases reveal the evolutionary origin of telomerase Defense-associated reverse transcriptases (DRTs) employ diverse and distinctive mechanisms of cDNA synthesis to protect bacteria against viral infection. However, much of DRT family diversity remains ...

1/10 Genome maintenance by telomerase is a fundamental process in nearly all eukaryotes. But where does it come from?

Today, we report the discovery of telomerase homologs in a family of antiviral RTs, revealing an unexpected evolutionary origin in bacteria.
www.biorxiv.org/content/10.1...

Perfect timing in the field for a beautiful review on NAD+ in bacterial immunity by @hugovaysset.bsky.social and @audeber.bsky.social @cp-molcell.bsky.social

#MicroSky

www.cell.com/molecular-ce...

Isolation, engineering and ecology of temperate phages from the human gut - Nature Human host-associated cellular products may act as induction agents for bacteriophages.

www.nature.com/articles/s41...

#phagesky #phage #microsky #microbiome

The Panoptes system uses decoy cyclic nucleotides to defend against phage - Nature The Panoptes antiphage system defends bacteria by detecting phage-encoded counter-defences that sequester cyclic nucleotide signals, triggering membrane disruption and highlighting a broader strategy of sensing immune evasion through second-messenger surveillance.

Our story describing the Panoptes bacterial immune defense system is now finally peer-reviewed and published today! www.nature.com/articles/s41...

Discovery of phage defense systems through component modularity networks Phage defense systems in bacteria exhibit high degrees of modularity, with sensing, signal transmission, and effector enzymes frequently being exchanged among phage defense gene clusters. In this study, we capitalized on this modularity to discover phage defense systems by searching for defense-associated modules in new gene contexts. This approach revealed a large and interconnected network of modular components distributed across diverse gene clusters. From over 500 candidate defense systems, we selected nine for experimental testing and validated three: Dionysus, a TerB-encoding system that disrupts early phage infection vesicle formation by Jumbo phages; Ophion, a Radical SAM-containing system that prevents the formation of the Jumbo phage nucleus; and Ambrosia, a tightly regulated RM-like system. Collectively, we demonstrate that leveraging the modular architecture of phage defense systems is an effective approach to their discovery. ### Competing Interest Statement The authors have declared no competing interest. European Research Council, 101003229 Netherlands Organisation for Scientific Research, VI.C.192.027, OCENW.XS23.1.006 Koningin Wilhelmina Fonds, 15602

Discovery of phage defense systems through component modularity networks | bioRxiv https://www.biorxiv.org/content/10.1101/2025.09.30.679545v1

You’ve heard of ubiquitination, meet deazaguanylation: Doug Wassarman in our lab discovered phage defense pathways have co-opted Q nucleobase biosynthetic enzymes to catalyze a new form of protein conjugation chemistry @science.org

www.science.org/doi/10.1126/...

I'm really happy to have been granted an @erc.europa.eu Starting Grant! We'll study the molecular principles of RNA phages—from infection to replication to bacterial immunity. Interested in joining? Feel free to reach out! Formal job ads to follow.

More info here:

tinyurl.com/RIBO-PHAGE

#ERCStG

Super excited to receive the ERC starting grant to explore what phage-bacteria interactions can teach us on host-pathogen conflicts 🤩 I'm immensely grateful to my wonderful team and to present and past mentors 🙏

Synthetically designed anti-defense proteins overcome barriers to bacterial transformation and phage infection Bacterial defense systems present considerable barriers to both phage infection and plasmid transformation. These systems target mobile genetic elements, limiting the efficacy of bacteriophage-based t...

📢 New preprint alert!
We designed synthetic proteins that can block bacterial immune systems, allowing phages + plasmids to overcome natural defenses.
This could transform phage therapy + genetic engineering.
Here’s what we found 🧵
Preprint🔗: www.biorxiv.org/content/10.1...

Functional diversity of phage sponge proteins that sequester host immune signals Multiple bacterial immune systems, including CBASS, Thoeris, and Pycsar, employ signaling molecules that activate the immune response following phage infection. Phages counteract bacterial immune sign...

📢 Preprint out!
Together with @reneechang.bsky.social @kranzuschlab.bsky.social and the amazing @soreklab.bsky.social, we explored viral sponges to map their diversity and function.

Discovered huge diversity, including sponges that inhibit Pycsar & Type IV Thoeris!

www.biorxiv.org/content/10.1...

Protein Structure Informed Bacteriophage Genome Annotation with Phold Bacteriophage (phage) genome annotation is essential for understanding their functional potential and suitability for use as therapeutic agents. Here we introduce Phold, an annotation framework utilis...

Stoked to finally have a preprint out for Phold, our tool that uses protein structural information to enhance phage genome annotation #phagesky 1/n

www.biorxiv.org/content/10.1...

Manipulation of the nucleotide pool in human, bacterial and plant immunity - Nature Reviews Immunology Modification of the nucleotide pool is emerging as key to innate immunity in animals, plants and bacteria. This Review explains how immune pathways conserved from bacteria to humans manipulate the nuc...

We wrote a review on the free nucleotide pool as a central playground in human, bacterial, and plant immunity – now out in Nature Reviews in Immunology

www.nature.com/articles/s41...

Was fun to write this piece with Dina Hochhauser!

Here is a thread to explain the premises

1/

1/16 New pre-print from the Sternberg Lab!
We uncover how temperate phages can use RNA-guided transcription factors to remodel the flagellar composition of their bacterial host and enhance their fitness.
Find the preprint and full story here: tinyurl.com/mshwjd77

🦠🧍‍♀️From bacterial to human immunity.

We report in @science.org the discovery of a human homolog of SIR2 antiphage proteins that participates in the TLR pathway of animal innate immunity.
Co-led wt @enzopoirier.bsky.social by D. Bonhomme and @hugovaysset.bsky.social

www.science.org/doi/10.1126/...

Next up from our lab - a ring nuclease with a novel fold which cleaves all cOA species involved in Type III CRISPR defence. It's also found in plasmid and phage genomes, where it presumably functions as an anti-CRISPR.
www.biorxiv.org/content/10.1...

A new preprint led by Sonomi Yamaguchi in our lab describes a bacterial anti-phage defense system named Clover that uses nucleotide signals to both activate and inhibit host immunity.

www.biorxiv.org/content/10.1...

SAM-AMP lyases in type III CRISPR defence Abstract. Type III CRISPR systems detect non-self RNA and activate the enzymatic Cas10 subunit, which generates nucleotide second messengers for activation

Here we show how the type III signalling molecule SAM-AMP is bound and degraded by a specialised lyase enzyme encoded in cellular and phage genomes. More great work by @haotianchi.bsky.social and the team. @uniofstandrews.bsky.social
academic.oup.com/nar/article/...

📢Preprint out!
Excited to share my final work from the @soreklab.bsky.social!

We mined phage dark matter using structural features shared by anti-defense proteins (viral tools that help phages bypass bacterial immunity) to guide discovery.

Found 3 new families targeting immune signaling!

Excited to unveil Boltz-2, our new model capable not only of predicting structures but also binding affinities! Boltz-2 is the first AI model to approach the performance of FEP simulations while being more than 1000x faster! All open-sourced under MIT license! A thread… 🤗🚀

Evolution of antivirus defense in prokaryotes depending on the environmental virus prevalence and virome dynamics Prokaryotes can acquire antivirus immunity via two fundamentally distinct types of processes: direct interaction with the virus as in CRISPR-Cas adaptive immunity systems and horizontal gene transfer ...

Cool work by Sanasar investigating how bacteria-phage dynamics affect the distribution of antiphage defense systems in the genome www.biorxiv.org/content/10.1...

We're thrilled to share the published version of our DRT9 story, online today @nature.com! Congratulations to all authors!

www.nature.com/articles/s41...

Really excited to share our resource and analysis of AlphaFold-predicted monomers and homodimers across viruses and phages. Project driven by fab PhD student @rodai.bsky.social and with our great collaborators Joana Pereira @joanampereira.bsky.social and @ninjani.bsky.social