Florian Tesson

Recurrent acquisition of nuclease-protease pairs in antiviral immunity Antiviral immune systems diversify by integrating new genes into existing pathways, creating new mechanisms of viral resistance. We identified genes encoding a predicted nuclease paired with a trypsin...

Excited to finally share this work!
We noticed a pair of genes - a nuclease and a protease - shuffles between antiviral systems. We show how proteolysis activates the nuclease, triggering defense in known and unknown immune contexts.
tinyurl.com/2uwwy4ty

Temperate phages enhance host fitness via RNA-guided flagellar remodeling Bacterial flagella drive motility and chemotaxis while also playing critical roles in host-pathogen interactions, as their oligomeric subunit, flagellin, is specifically recognized by the mammalian im...

Excited to share the work that’s been on my mind for the past 2 years, now on bioRxiv!
Led with Matt Walker, and my first project in the Sternberg Lab .
Check it out ⬇️

tinyurl.com/mshwjd77

Bacterial Schlafens mediate anti-phage defense Human Schlafen proteins restrict viral replication by cleaving tRNA, thereby suppressing protein synthesis. Although the ribonuclease domain of Schlafen proteins is conserved across all domains of lif...

First preprint from the Nemudryi Lab! 🍾

In this work, we link antiviral immunity in bacteria and humans by showing that homologs of human Schlafen nucleases protect bacteria from phages.

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

A human protein inherited from bacteria reveals an overlooked aspect of human immunity What if the study of bacteria could illuminate our understanding of human immunity? In recent years, scientists have been exploring unexpected links between human proteins involved in the body’s defen...

🧬 From bacteria to humans: a new study led by @institutcurie.bsky.social, @institutpasteur.bsky.social & @inserm.fr reveals SIRal, a novel human immune protein with ancestral roots. A new path for immunotherapy?

🔗 Read: www.pasteur.fr/en/press-are...

🦠🧍‍♀️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/...

📢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!

Signez la pétition Sauvons le Palais de la découverte

Le Palais de la Découverte est menacé! Il a contribué à éveiller ma passion pour la science quand j'étais petit. Nous devons tout faire pour protéger ce lieu unique qui a toute sa place au cœur de Paris. Signez la pétition ici: chng.it/BnR9gZvhL2

The Viral AlphaFold Database of monomers and homodimers reveals conserved protein folds in viruses of bacteria, archaea, and eukaryotes https://www.biorxiv.org/content/10.1101/2025.05.14.653371v1

Sedentary chromosomal integrons as biobanks of bacterial antiphage defense systems Integrons are genetic systems that drive bacterial adaptation by acquiring, expressing, and shuffling gene cassettes. While mobile integrons are well known for spreading antibiotic resistance genes, t...

White smoke, we have a new pope and also 16 new anti-phages systems in sedentary integrons (SCIs) !
In collaboration with the Rocha lab, we show in our new paper that cassettes of these large platforms encode many known anti-phage defenses, and uncovered 16 new ones.
www.science.org/doi/10.1126/...

Out in Nature today: A new immune signaling molecule, His-ADPR, is produced by defensive TIR domain proteins in bacteria to protect from phage

Joint work with the Tamulaitienė and Kranzusch labs

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

Congrats Carmel Avraham, Dziugas Sabonis, Renee Chang and co-authors!

It was an honor for my lab and myself to host the meeting on the Immune Systems of Bacteria. Such a high from all the incredible science and sharing with scientists from the whole world the greatness of Paris in the spring.
Vive la science, et vive Paris!

Structural basis for Lamassu-based antiviral immunity and its evolution from DNA repair machinery https://www.biorxiv.org/content/10.1101/2025.04.02.646746v1

CBASS, CRISPR, and mCpol- oh my! What a satisfying collaboration with @aaronwhiteley.bsky.social 's lab- we uncovered a new cyclic dinucleotide signaling pathway, but it doesn't work how you'd expect! Check out the thread from @aesully98.bsky.social for an overview of the most important findings!

Genetics, ecology and evolution of phage satellites Nature Reviews Microbiology, Published online: 27 March 2025; doi:10.1038/s41579-025-01156-zIn this Review, Penadés et al. explore the genetics, potential origins and life cycle of phage satellites, and they discuss the impact of these elements on the evolution of other mobile genetic elements and their host bacteria.

New online! Genetics, ecology and evolution of phage satellites

Protein-primed DNA homopolymer synthesis by an antiviral reverse transcriptase Bacteria defend themselves from viral predation using diverse immune systems, many of which sense and target foreign DNA for degradation. Defense-associated reverse transcriptase (DRT) systems provide...

Hello BlueSky! Inaugural post here from the Sternberg Lab. We're excited to share our latest work, in which we teamed up with the @WiedenheftLab to study how DRT9 reverse transcriptases provide antiviral immunity. Here’s what we found: www.biorxiv.org/content/10.1...

New version of DefenseFinder available defensefinder.mdmlab.fr (& cli)

Now encompassing 263 systems (+111 this year..!).

Thanks @ftesson.bsky.social, DefenseFinder grandmaster. Full list of systems here: defense-finder-models/List_system_article.md at master · mdmparis/defense-finder-models

Specificity and Mechanism of tRNA cleavage by the AriB Toprim nuclease of the PARIS bacterial immune system Transfer RNA molecules have been recently recognized as widespread targets of bacterial immune systems. Translation inhibition through tRNA cleavage or modification inhibits phage propagation, thereby...

Happy to share our latest piece of work on the PARIS bacterial immune system. We performed a detailed characterization of the AriB Toprim nuclease, the effector of PARIS immunity.

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

Image with text that reads: It's happening now: I know it's totally overwhelming but here are just a handful of things happening in US Science & public health RIGHT NOW. I need you to know, so you can realise how you are being defrauded from a healthy, disease free future, with thriving science. I need you to know, so you can tell others.

Huge thanks to my sister for helping put these together.

I'm thrilled to announce our latest work is now published in Cell! Viruses encode numerous proteins that inhibit host defenses, but identifying immune-modulatory proteins among millions of viral sequences has been nearly impossible - until now! www.cell.com/cell/fulltex...

Phage defence system abundances vary across environments and increase with viral density www.biorxiv.org/content/10.1... #jcampubs

Institut Pasteur decides to leave X The Institut Pasteur, a research organization which for more than 130 years has been committed to tackling infectious diseases, sharing knowledge and defending science, has decided to leave X because ...

The Institut Pasteur has decided to leave X (formerly Twitter) to join BlueSky! 🦋
The Institut Pasteur made this decision due to several serious issues observed on the X platform since its acquisition. Join us here to continue advocating for science. www.pasteur.fr/en/home/pres...

Update_DefenseFinder_open

If you want to help us update DefenseFinder, you can add all the systems we could have missed on this table (suggestion sheet): docs.google.com/spreadsheets...
You can also see which systems are already included in the next version of DefenseFinder

👋 Hi antiphage defense community, we are soon releasing an update of DefenseFinder.

We are doing our best to include all the great discoveries from the community, but with so much going on we might miss things.

Please answer wt preprints/papers with new systems or mail/git them to us. 🙏

Excited to share our work using machine learning to predict anti-phage defense systems!

1/n

What is the diversity of antiphage systems out there ?

We used protein and genomic language models (and defense score!) to start bringing some answers: >45 000 protein families.

Leb by E. Mordret.
www.biorxiv.org/content/10.1...

Interactive UMAP to have fun
mdmparis.github.io/antiphage-la...

Exploring the diversity of anti-defense systems across prokaryotes, phages and mobile genetic elements Abstract. The co-evolution of prokaryotes, phages and mobile genetic elements (MGEs) has driven the diversification of defense and anti-defense systems ali

Out in NAR, AntiDefenseFinder & our "systematic" analysis of inhibitors of antiphage systems wt Bondy-Denomy lab led by @ftesson.bsky.social and E. Huiting.

Not so "systematic" as very few known, fun stuff on MGE, antidefense islands and cool phages exaptations!

academic.oup.com/nar/advance-...

Diversification of molecular pattern recognition in bacterial NLR-like proteins - Nature Communications Avs proteins are bacterial anti-phage pattern recognition receptors evolutionarily related to eukaryotic NLRs. Here, Béchon et al show that a single bacterial Avs can recognize different phage protein...

Happy to see our paper out @ Nat Comm

We discovered a bacterial NLR-like pattern recognition receptor that can sense 3 different viral proteins as a signature for infection. This explains its broad defense against different phage families

Congrats Nathalie Béchon!

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

Multigenerational Proteolytic Inactivation of Restriction Upon Subtle Genomic Hypomethylation Restriction-modification (R-M) systems, present in most bacterial genomes, protect against phage infection by detecting and degrading invading foreign DNA. However, like many prokaryotic anti-phage sy...

Another day, another cool recent preprint on bacterial immunity. #Phagesky

This one is on an super cool regulation of Restriction-Modification systems. Post-translational modifications that are temperature dependent AND inherited over 60 generations.

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

Prediction of strain level phage–host interactions across the Escherichia genus using only genomic information - Nature Microbiology Phage–host interactions are computationally predicted using only genomic information, highlighting future research directions and enabling generation of custom phage cocktails.

Out in Nature Microbiology, we predicted phage-bacteria interactions in E. coli species using only genomic information.

Adsorption, not defense systems, is the main driver at this scale (relevant for a phage therapy context), leading to tailored cocktails!

www.nature.com/articles/s41...
🧵👇

💻🧫 New preprint: How accurately can we predict diverse phage bacteria-interactions from their genomes only ? We created a matrix of >38k phage-bacteria interactions to find out (=> AUROC 86%) & used our predictions to recommend tailored phage cocktails.
www.biorxiv.org/content/10.1...