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Joe McKellar @viroscope.bsky.social · 12h

Thanks so much! That means so much to me 🤩
Working with MX1 proteins was definitely not easy, but coming across this mechanism felt super rewarding!
My question now is: what about the mechanisms behind the early stage blocks of the avian flus? 😄

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Joe McKellar @viroscope.bsky.social · Jun 30

Go and vote for @dianabrychka.bsky.social's stunning image of a brain organoid ! 🤩

Diana Brychka @dianabrychka.bsky.social · Jun 30

My little brain organoid is in a contest. If you find it pretty, you can vote for it 🤍
Go look at the other images too, they’re stunning!

Here is the link to vote:
m.cmpgn.page/jxZjTb?sre=2...

#MicroscopyMonday #SciArt

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Joe McKellar @viroscope.bsky.social · Jun 27

A Boa Constrictor brain-derived cell expressing a viral glycoprotein (magenta) and stained for actin (yellow) and DNA (white).

#FluorescenceFriday

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Joe McKellar @viroscope.bsky.social · May 30

HFF cells stained for DNA ⚪, intermediate filaments 🟠, microtubules 🔴 and actin 🔵.

#FluorescenceFriday
#SciArt

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Joe McKellar @viroscope.bsky.social · May 23

Aha thank you for the compliment!

Joe McKellar @viroscope.bsky.social · May 23

For #FluorescenceFriday, a field of individual VSV (rod-shaped, in 🟧) and Deltavirus (dot-shaped, in 🔵) particles imaged by STED (20nm per pixel).

We now know that Deltaviruses can package inside particles of other viruses.

Can you find any of these dual particles in this field?

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Joe McKellar @viroscope.bsky.social · May 16

Beautiful image!

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Reposted by Joe McKellar

Mathieu Preußner @mathpreu.bsky.social · May 16

🔬✨ Today for #FluorescenceFriday:
A close-up of the dorsal part of the first gill arch in a mature zebrafish.
The intricate vascular network supporting respiration, visualized using kdrl:mcherry.

#Zebrafish #DevBio #Microscopy #Fluorescence #SciArt

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Joe McKellar @viroscope.bsky.social · May 16

Viruses in the forest of the lungs.

Human airway epithelia stained for actin 🟢 and SARS-CoV-2 RNA 🟣.

#FluorescenceFriday
#SciArt

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Joe McKellar @viroscope.bsky.social · May 12

Thank you for sharing our work! It was great discussing with you at #ECV2025 !

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Reposted by Joe McKellar

Joe Grove @grovearmada.bsky.social · May 10

Saw this presented at ECV 2025. Fanastic and thought provoking work! Congrats to @viroscope.bsky.social, @karimaj.bsky.social and coauthors.

Joe McKellar @viroscope.bsky.social · May 10

⚠️ Discovery of a new mode of viral transmission:

Deltaviruses spread through a viral Trojan Horse !

These viral satellites that do not encode their own glycoproteins, are in fact physically encapsulated within their helper virus particles!

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

A thread 1/14

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Reposted by Joe McKellar

Thelonevirologist @thelonevirologist.bsky.social · May 12

Deltaviruses spread through a viral Trojan Horse www.biorxiv.org/content/10.1...

Deltaviruses spread through a viral Trojan Horse

Hepatitis D-like viral satellites, known as deltaviruses, have been recently discovered in a wide range of animals. These viruses are thought to expropriate glycoproteins from helper viruses to form i...

www.biorxiv.org

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Reposted by Joe McKellar

bioRxiv Microbiology @biorxiv-microbiol.bsky.social · May 10

Deltaviruses spread through a viral Trojan Horse https://www.biorxiv.org/content/10.1101/2025.05.09.653040v1

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Reposted by Joe McKellar

bioRxivpreprint @biorxivpreprint.bsky.social · May 10

Deltaviruses spread through a viral Trojan Horse https://www.biorxiv.org/content/10.1101/2025.05.09.653040v1

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Joe McKellar @viroscope.bsky.social · May 10

Thanks Maria! :)
It depends on the helper virus! With VSV and UGV the deltavirus free particles are productive, just much less so than the Trojan Horse particles (over 100-fold for UGV). However for HSV-1 they are totally unproductive, probably because they can't access/decorate with HSV-1 GPs!

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Reposted by Joe McKellar

Karim Majzoub @karimaj.bsky.social · May 10

With Joe in our lab, we discovered a new mode of how some viral sattelites can spread : A form of viral hitchhiking we termed Viral Trojan Horse ! check our paper on biorXiv : www.biorxiv.org/content/10.1...

Joe McKellar @viroscope.bsky.social · May 10

⚠️ Discovery of a new mode of viral transmission:

Deltaviruses spread through a viral Trojan Horse !

These viral satellites that do not encode their own glycoproteins, are in fact physically encapsulated within their helper virus particles!

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

A thread 1/14

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Joe McKellar @viroscope.bsky.social · May 10

Don't hesitate to get in touch if you'd like to know more!

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Joe McKellar @viroscope.bsky.social · May 10

Special thanks to Aurélien Fouillen, who was there since the initial observations and who was essential for all the EM data of the paper, and of course @karimaj.bsky.social, who was extremely supportive in my pursual of what was originally an anecdotal, unexpected, observation!

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Joe McKellar @viroscope.bsky.social · May 10

I would like to thank everyone involved in this project, for their expertise, their ideas and their enthusiasm!

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Joe McKellar @viroscope.bsky.social · May 10

This opens up many questions, as to whether deltaviruses may be causative agents of disease in humans, associating with helper viruses of different origins.

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Joe McKellar @viroscope.bsky.social · May 10

To conclude, we evidence a novel mode of viral transmission – spread through a viral Trojan Horse.

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Joe McKellar @viroscope.bsky.social · May 10

We show that snake deltavirus can use a reptarenavirus (UGV-1) as a viral Trojan Horse, being found inside of their particles, and that these Trojan Horse particles are over 100-fold more infectious than free deltavirus particles!

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Joe McKellar @viroscope.bsky.social · May 10

Finally, the only animal deltavirus - helper virus association accepted to date is that of snake deltavirus and reptarenavirus, found in boa constrictors suffering from Boid Inclusion Body Disease.

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Joe McKellar @viroscope.bsky.social · May 10

Furthermore, we show the tissue- and species-shifting capabilities that Trojan Horse particles allow, by showing infection of human neuronal cells with HSV-1 Trojan Horse particles!

Neuronal marker in 🟣 HSV-1 in 🟡, deltavirus in 🔵 and DNA in ⚪.

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Joe McKellar @viroscope.bsky.social · May 10

Separating the Trojan Horse particles from the free deltavirus particles showed us that deltaviruses are actually unable to steal the glycoproteins of HSV-1 to decorate their own free particles and that the Trojan Horse particles are the only possible infectious unit when HSV-1 is a helper.

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