Luuk Loeff
@lloeff.bsky.social
Principal Investigator at Leiden University Medical Center Host-Defence | Structural biology | Single-molecule Biophysics http://www.loefflab.com
We’re so excited to share our new paper, where we tackle the wealth of structural and functional diversity of anti-phage sensors across bacteria (1/6)
Nature@nature.com · last wk.Nature research paper: Diverse bacterial pattern recognition receptors sense the core phage proteome go.nature.com/45fpXCZ
Out @cp-cellhostmicrobe.bsky.social, natural products meet bacterial immunity! We used genomics to identify lanthivirins: a family of >2,000 lanthipeptide BGCs that protect Actinobacteria against phages. Led by @hshomar.bsky.social & @mariegllm.bsky.social www.sciencedirect.com/science/arti...
A family of lanthipeptides with anti-phage function
Bacteria produce natural products to adapt to their environments, with phage interactions as major ecological and evolutionary drivers. While some nat…
sciencedirect.com
A new PAMP, a new innate immunity principle and a new preclinical application. I am so pleased to share our study on STING activation mechanisms in health and disease. Led by the fantastic Stephanie Ragland, follow the link below for a summary of all we learned. www.cell.com/immunity/ful...
Purine and pyrimidine-based bacterial cyclic dinucleotides egress the phagosome and activate the innate immune sensor STING
Innate immune recognition of bacteria is thought to center on cell-surface or endosomal pattern recognition receptors such as TLRs. Ragland et al. identify an intraphagosomal cyclic dinucleotide (CDN)...
cell.com
🧬 Thrilled to share our latest @biorxiv-microbiol.bsky.social preprint! Here we find that Retron-IX build crazy supramolecular rings scaffolded by DNA molecules that sense phage infection! www.biorxiv.org/content/10.6... Read more below🧵! (1/X)
1/10 🚨Preprint! One RING to rule them all (phages)👑💍⚔️ Bacteria build giant DNA-scaffolded RNase rings (larger than the ribosome!) to shut down viral infection🧬🧵👇 biorxiv.org/content/10.6...
🚨 We're hiring! My new lab at EMBL Hamburg is looking for a Research Technician. I'm looking for someone excited by phages, metabolism, enzymes, structural biology and bacterial immunity—if you know the right person, please share this post!🧵⬇️ Apply here: embl.wd103.myworkdayjobs.com/en-US/EMBL/j...
Research Technician (Osterman Group – Metabolism-driven immunity)
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...
embl.wd103.myworkdayjobs.com
1/11 New preprint from the Sternberg lab in collaboration with the Fernández lab! We are excited to share our structure-function study of DRT10, a bacterial defense-associated reverse transcriptase that synthesizes long tandem-repeat DNA.🧵 Read the full story here: www.biorxiv.org/content/10.6...
Mechanism of tandem-repeat DNA synthesis by an antiviral reverse transcriptase
Defense-associated reverse transcriptases (DRTs) employ DNA synthesis to protect bacteria against phage infection[1][1],[2][2]. We previously showed that DRT10, a tripartite system comprising an RT, a...
biorxiv.org
Our paper out in Science today: The Metis defense system senses molecular byproducts released when a phage degrades the bacterial genome, and then prevents replication of the phage in the infected cell Congratulations @ostermanilya.bsky.social and co-authors!
Bacteria sense virus-induced genome degradation via methylated mononucleotides
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...
science.org
Osterman Ilya@ostermanilya.bsky.social · 4w agoExcited to share that our Metis story is now published in Science! 🎉 Bacteria can sense phage-induced degradation of their genome and activate immunity. Many thanks to everyone who contributed to this work. 📄 www.science.org/doi/10.1126/... More details in my earlier thread 🧵⬇️
Humans and bacteria share strategies to defend against viruses. We wondered: could they use each other's genes? Yes, both can! Bacteria can use human immune genes to defend against phages AND Human cells can use bacterial genes for viral defense. www.biorxiv.org/content/10.6...
Bacterial and human exonucleases mediate interkingdom antiviral immunity
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...
biorxiv.org
Join us! Postdoc position (2-3 years) in our lab @molbiolau.bsky.social Looking for candidates with experience in cell culture, genome editing, biochemistry, and/or structural biology. Application opens in August via AU's system but informal enquiries by email are welcome from now. (1/2)
The DdmDE defense system eradicates plasmids by target-centered bidirectional ssDNA loop extrusion and site-specific cleavage
The DdmDE defense system eradicates plasmids by target-centered bidirectional ssDNA loop extrusion and site-specific cleavage
Yang et al. reveal a dynamic DdmDE-mediated plasmid clearance pathway. Transient DNA bubbles permit promiscuous DdmE binding, while target specificity arises from slower dissociation at matched sites. DdmE then recruits a DdmD dimer to drive target-centered, bidirectional dsDNA unwinding. Free DdmD subsequently coats extruded ssDNA to enable site-specific endonucleolytic cleavage.
dlvr.it
How do pathogens disarm plant immunity? We discovered a widespread strategy used by plant bacterial pathogens: they directly cleave a conserved immune signaling molecule produced by plant immune receptors. www.biorxiv.org/content/10.6...
biorxiv.org
How do human cells defend against viruses? @sgfern.bsky.social discovers that human immune proteins named ISGs target ancient features of replication shared between animal and bacterial viruses – opening analysis of human immunity to the power of bacterial genetics www.biorxiv.org/content/10.6...
@romihadary.bsky.social and @soreklab.bsky.social 's discovery that sponge proteins constitute enormous families of viral immune evasion factors is now out in @natmicrobiol.nature.com @reneechang.bsky.social and our lab were happy to help with this story! www.nature.com/articles/s41...
Functional diversity of phage sponge proteins that sequester host immune signals - Nature Microbiology
A functional screen reveals phage sponge proteins that bind Pycsar, Thoeris and CBASS signalling molecules to inhibit bacterial immunity.
nature.com
Kranzusch Lab@kranzuschlab.bsky.social · 11mo agoTwo major breakthroughs for the nucleotide immune signaling field in pre-print by @romihadary.bsky.social @soreklab.bsky.social www.biorxiv.org/content/10.1... (1) Beautiful bioinformatic analyses reveal known viral nucleotide sponges are members of enormous protein families ubiquitous in phages
Our aRES story is finally out 😀 Beyond what was reported in the preprint, we found that aRES is activated by direct binding of the phage DNA polymerase. Another NAD-degrading defense system — and multiple phage strategies to overcome it. www.sciencedirect.com/science/arti...
Bacterial defense via RES-mediated NAD+ depletion is countered by phage phosphatases
Many bacterial defense systems restrict phage infection by breaking down the molecule nicotinamide (Nam) adenine dinucleotide (NAD+) into adenosine di…
sciencedirect.com
Osterman Ilya@ostermanilya.bsky.social · 6mo ago🧬 Metabolic arms race continues! We discovered a new NAD⁺-depleting bacterial immune system aRES and phage enzymes that overcome it. Our preprint is out: www.biorxiv.org/content/10.6...
(1/6) Thrilled to share this story! In our preprint from my PhD in the @kranzuschlab.bsky.social, with help from the Hatfull lab and @soreklab.bsky.social, we discover RyDEP, a phage-encoded RyR-domain glycosidase that allows phages to evade Thoeris defense. Highlights below! doi.org/10.64898/202...
Amazing piece from @science.org and @richardastone.bsky.social on our field and the growing connection between human and bacterial immunity! #microsky #virosky #immunosky www.science.org/content/arti...
Ancient wars between microbes gave us key immune defenses
A better understanding of battles between bacteria and viruses could inspire new medicines
science.org
1/8 🚨 New preprint from the @sternberglab.bsky.social & @martinjinek.bsky.social labs! CRISPR-associated transposases (CASTs) insert large DNA cargoes at precise genomic locations — no double-strand breaks needed.
Like a prophage being awakened from its slumber, the phage field has seen a lot of renewed activity during the last decade. Check out our new @natrevmicro.nature.com review on the temperate phage life cycle here to stay up-to-date 🧫🦠 www.nature.com/articles/s41...
Revisiting the life cycle of temperate phages - Nature Reviews Microbiology
The life cycle of temperate bacteriophages involves lytic or lysogenic cycles and has historically served as a model for studying genetic regulation. This Review provides an updated overview of these ...
nature.com
Some phages are named after gods or rivers, this one was named by journalist Thilo Mischke @thilomischke.bsky.social after his grandma ("Oma Karin") while filming in our lab. It's a cool phage that should be temperate but became virulent due to a transposon at its lysogeny control! ⛓️💥💪🏼
Excited to see this online! The structure of the CAST type I holo-complex. Congrats to all involved! By the labs of @martinjinek.bsky.social & @sternberglab.bsky.social.
cryoEM papers@cryoempapers.bsky.social · 3mo agoStructural basis of RNA-guided DNA integration by type I CRISPR-associated transposases www.biorxiv.org/content/10.64898/2026.05.18.725949v1 #cryoEM
Exciting paper! - www.researchsquare.com/article/rs-8...
Cyclic dinucleotides induce chromatin remodeling associated with long-lasting antiviral protection in flies and bees
cGAS-like receptors (cGLRs) are an important family of nucleic acid-sensing pattern recognition receptors in innate immunity, which produce cyclic dinucleotides (CDNs) to activate STING signaling and ...
researchsquare.com
And another preprint about the Druantia defense system 👏🏻👏🏻 in case you were missing some reading for the weekend, here we go bsky.app/profile/lloe...
Luuk Loeff@lloeff.bsky.social · 3mo agoHappy to share our latest pre-print on the Druantia defense system. We find that Type III Druantia uses a cooperative helicase-nuclease mechanism to sense and degrade replication-associated forked DNA structures. www.biorxiv.org/content/10.6... A🧵
Very happy to share our Druantia III–Zorya II synergy story, now on bioRxiv: www.biorxiv.org/cgi/content/short/2026.05.12.724681v1 It appears alongside several Druantia III papers from excellent colleagues, each telling a different part of the story. (links below)
biorxiv.org
Happy to share our latest pre-print on the Druantia defense system. We find that Type III Druantia uses a cooperative helicase-nuclease mechanism to sense and degrade replication-associated forked DNA structures. www.biorxiv.org/content/10.6... A🧵
biorxiv.org
When is an antiphage mechanism an evolved defence adaptation? This question has been on my mind for so long, because despite the field’s rapid progress there is currently no widely agreed framework in place to answer it. So @brownlab.bsky.social and I wrote this, and I'm happy to share the preprint!
The bacterial immune system: identifying evolved defense adaptations
ecoevorxiv.org
For 40 years the 8-nt ‘Kozak Sequence’ was thought to mark sites of translation initiation. In a new study, we revise this model by identifying an ~80-nt sequence—the extended Translation Initiation Sequence (eTIS)— that guides ribosomes to correct start sites. 🧵 www.biorxiv.org/content/10.6...
biorxiv.org
