Oleg Dmytrenko

The paradox of immune systems conservation between prokaryotes and eukaryotes Nature Reviews Microbiology, Published online: 05 February 2026; doi:10.1038/s41579-026-01284-0The widespread prokaryotic immune systems, in particular restriction–modification, CRISPR–Cas and defensive toxin–antitoxin systems, are absent in eukaryotes, whereas relatively rare ones, such as Argonautes and antiviral STAND NTPases, became central to eukaryotic innate immunity. In this Comment, we hypothesize that the cause of this paradox is the drastic reduction of horizontal gene transfer rate in eukaryotes.

New online! The paradox of immune systems conservation between prokaryotes and eukaryotes

Beyond gene scissors: New CRISPR mechanism discovered Team from Würzburg, Braunschweig, and the US identifies Cas12a3 nuclease showing precise activity | Study just published in Nature

The #CRISPR “gene scissors” have become an important basis for genome-editing technologies in many fields. 🧬✂️ A team from the #HIRI in Würzburg has now demonstrated that these CRISPR-Cas systems are even more versatile than previously thought. Read more: www.helmholtz-hiri.de/en/newsroom/...

Kryo-Elektronenmikroskopaufnahme der Nuklease Cas12a3 mit einer illustrierten Schere

#CRISPR kann mehr als gedacht: Ein Team des @helmholtz-hiri.bsky.social hat mit Forschenden des HZI & aus den USA eine neue Nuklease entschlüsselt: In @nature.com zeigen sie, dass Cas12a3 Transfer-Ribonukleinsäuren schneidet, um infizierte Zellen lahmzulegen. www.helmholtz-hzi.de/media-center...

RNA-triggered Cas12a3 cleaves tRNA tails to execute bacterial immunity - Nature Cas12a3 nucleases constitute a distinct clade of type V CRISPR–Cas bacterial immune systems that preferentially cleave the 3′ tails of tRNAs after recognition of target RNA to induce growth arres...

Our paper is out! Hiding in plain sight among Cas12a nucleases, Cas12a3 cleaves not its RNA target but the 3′ ends of tRNA. Huge thanks to all who made this possible, especially the Beisel lab, Biao & Dirk for the structure, & @sebastianglatt.bsky.social for all things tRNA. doi.org/10.1038/s415...

Russia is a terrorist state!

“Paraxenoviridae”, a putative family of ubiquitous marine bacteriophages with double-stranded RNA genomes Fragmented and primer Ligated DsRNA Sequencing (FLDS) was used to reconstruct five complete, bisegmented RNA genomes of paraxenoviruses, a group of viruses that was previously identified in the ocean ...

Preprint alert: Putative phages with dsRNA genomes. Intriguing what bacteria they may infect. Nature’s diversity continues to astonish! www.biorxiv.org/content/10.1...

Kyiv, not Kiev — How Ukrainians reclaimed their capital For decades, if not more, English speakers the world over referred to Ukraine’s capital as Kiev, pronouncing it kee-yev. Few people knew they were using the Russian name for the city. The city is pro...

The Russian spelling and pronunciation of Kyiv throughout the ages was no accident. While the name gets its origin from an empire that predates Russia, a series of policies by the Russian Empire and the Soviet Union that sought to Russify Ukraine and the Ukrainian language distorted its roots.

I’m very fortunate to be at the 2025 CRISPR Meeting in Christchurch to share our latest work on the quirky Cas12a diversity. What an amazing crowd and location!
@crisprmeeting.bsky.social

TIR signaling activates caspase-like immunity in bacteria Caspase family proteases and Toll/interleukin-1 receptor (TIR)-domain proteins have central roles in innate immunity and regulated cell death in humans. We describe a bacterial immune system comprisin...

The diversity of microbial defenses is amazing! Type IV Thoeris system shows an ancient innate immunity mechanism which uses a TIR protein to make N7-cADPR, activating a caspase-like protease to block phages. Learn more: www.science.org/doi/10.1126/...

Our paper out @Nature: CARD domains mediate anti-phage defense in bacterial gasdermin systems

CARDs are essential for caspase recruitment during human inflammasome activation. We now find them in bacterial immune systems

Congrats Tana Wein! Thank you Kranzusch lab!
www.nature.com/articles/s41...

Das Ende einer Ära: Heute fand die allerletzte Klasse in meinem geliebten Yogastudio statt, das mir in den letzten sechs Jahren ein Zufluchtsort war. Danke, Clau, für all die Posen und erholsamen Savasanas.

AI-driven discovery of host thioredoxin as a CRISPR enhancer of phage-encoded miniature Cas12 hacker nuclease The evolutionary arms race between bacteriophages and their bacterial hosts has driven the evolution of sophisticated adaptive immune systems, such as CRISPR-Cas, as a crucial defense mechanism. While...

This is just wild: using AI-driven structural predictions, this study discovered how a phage-encoded “Cas12 hacker” hijacks the bacterial host’s thioredoxin enzyme to supercharge its DNA-cleaving ability. www.biorxiv.org/content/10.1...

Charting the epitranscriptomic landscape across RNA biotypes using native RNA nanopore sequencing RNA modifications are conserved chemical features found in all domains of life and across diverse RNA biotypes, shaping gene expression profiles and e…

An excellent review on direct Nanopore sequencing of RNA for detecting epigenetic modifications. We are clearly just at the beginning of this journey, with many exciting discoveries to come. www.sciencedirect.com/science/arti...

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🧬 Save the date! The EMBO Workshop "The Immune System of Bacteria" will uncover groundbreaking insights into bacterial defense systems. Join us April 8-10, 2025, at Institut Pasteur, Paris. Submit your abstracts by Feb. 28 👉 https://www.sisb2025.conferences-pasteur.org/home

Nucleic acid recognition during prokaryotic immunity Prokaryotes sense viral and plasmid nucleic acids to start defense pathways against these invaders. This review examines the different mechanisms of DNA and RNA recognition and how these distinguish s...

An excellent review on nucleic acid recognition in microbial immunity! www.cell.com/molecular-ce...

Hanging there! Hoping to post my next printing here too, soon!

What a fantastic lineup! I really hope to be there to soak in all the amazing science of microbial defenses!

Registration now open for the EMBO Workshop: Immune System of Bacteria !!!!

www.sisb2025.conferences-pasteur.org/home

Joins us in Institut Pasteur, Paris, April 8-10th.

Thank you for the insightful lecture on the role of RANK/L in bone remodeling, mammary gland development, and cancer therapeutics! Excited to see how the future of HZI takes shape!

Happy 🦃 day, everyone!

Congratulations @grunewald.bsky.social! It is an impressive accomplishment, showing how AI-designed binders can transform CAR-T therapies for resistant cancers!

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