Our paper has finally graduated from pre-print to peer-reviewed, pretty much unscathed, and is out now! www.cell.com/cell/fulltex...
24.07.2025 14:08 โ ๐ 53 ๐ 19 ๐ฌ 7 ๐ 6@zahadyv.bsky.social
Host-parasite interaction. Passionate about exploring how Toxoplasma and Neospora induce host cell genome instability. #JLUgiessen.
Our paper has finally graduated from pre-print to peer-reviewed, pretty much unscathed, and is out now! www.cell.com/cell/fulltex...
24.07.2025 14:08 โ ๐ 53 ๐ 19 ๐ฌ 7 ๐ 6Such a fascinating, albeit terrifying study! In case you didn't see it, the study was also covered in @theconversation.com
theconversation.com/a-common-par...
Could the answer to the male fertility crisis be lurking in your catโs litter tray?
Discovery that the worldโs most successful parasite can โdecapitateโ sperm offers a new path to understanding rising infertility among men
โ๏ธ @arthurscottgeddes.bsky.social
www.telegraph.co.uk/global-healt...
Excited to see our collaborative research featured in the Telegraph! Grateful for the amazing team effort behind it and hopeful it helps raise awareness about toxoplasmosis in men. Thanks @arthurscottgeddes.bsky.social for highlighting our research! www.telegraph.co.uk/global-healt... #Toxoplasmosis
18.06.2025 11:42 โ ๐ 4 ๐ 1 ๐ฌ 1 ๐ 0It turns out the worldโs most successful parasite can โdecapitateโ sperm. For @telglobalhealth.bsky.social I wrote about the implications of this discovery for our understanding of the male infertility crisis. With thanks to @zahadyv.bsky.social and Bill Sullivan
www.telegraph.co.uk/global-healt...
๐งต Ever wondered what Toxoplasma is doing in your brain years after that undercooked steak ๐ฅฉ or a sip of contaminated water? Turns out, it's been hiding in your brain ๐ง and we finally have a way to spot it. New study just dropped in EMBO Molecular Medicine ๐
doi.org/10.1038/s443...
Thanks Jean. I'm glad that you like it โบ๏ธ
05.05.2025 19:31 โ ๐ 0 ๐ 0 ๐ฌ 0 ๐ 07/ Why does this matter? Shows T. gondii can rapidly invade male reproductive organs reveals a novel mechanism of sperm damage and raises questions about potential impacts on male fertility. Is it interesting? check out the above link #Toxoplasma #ReproductiveHealth#Microbiology #Parasitology
04.05.2025 08:54 โ ๐ 0 ๐ 0 ๐ฌ 0 ๐ 06/ Surprisingly, ROS levels did not increase, and the acrosome reaction (key for fertilization) was unaffected. This suggests T. gondii damages sperm via direct mechanical disruption and mitochondrial dysfunction.
04.05.2025 08:54 โ ๐ 1 ๐ 0 ๐ฌ 1 ๐ 05/ Is this damage caused by direct contact or secreted molecules? We ruled out soluble factorsโonly direct parasite contact induced sperm decapitation. Extracellular vesicles (exosomes) also had no effect and no DNA fragmentation. But apoptosis & necrosis increased. MMP dropped sharply.
04.05.2025 08:54 โ ๐ 0 ๐ 0 ๐ฌ 1 ๐ 04/ Scanning electron microscopy (SEM) revealed: Parasites attaching to sperm heads/tails Twisted, coiled tails. Holes in sperm heads (!) and Some heads were completely emptied of content
04.05.2025 08:54 โ ๐ 0 ๐ 0 ๐ฌ 1 ๐ 03/ Next, we tested how T. gondii affects human sperm. After just 5 minutes of exposure: 22% of sperm lost their heads (vs. 1.6% in controls). By 15 min, headless sperm increased 8-fold!.
04.05.2025 08:54 โ ๐ 0 ๐ 0 ๐ฌ 1 ๐ 02/ But are these parasites still infectives? Yes. We extracted infected tissues, injected them into healthy mice, and confirmed new infections via PCR. The parasites remain viable and infectious!.
04.05.2025 08:54 โ ๐ 0 ๐ 0 ๐ฌ 1 ๐ 01/ T. gondii effects on male reproduction are poorly understood, and here we reveals how T.g invades testes, epididymis, and even damages. After 2 days tachyzoites were detected in both testes and epididymis with immune cell infiltration and structural damage in seminal tubules.
04.05.2025 08:54 โ ๐ 0 ๐ 0 ๐ฌ 1 ๐ 0๐จNew Research: Adverse impact of acute Toxoplasma gondii infection on human spermatozoa- The FEBS Journal - febs.onlinelibrary.wiley.com/doi/10.1111/.... Thanks to @mariaefrancia.bsky.social Lab and all wonderful people who collaborate to make this possible. Here below what we found :).
04.05.2025 08:54 โ ๐ 5 ๐ 1 ๐ฌ 2 ๐ 0๐๐ฝ
22.04.2025 18:14 โ ๐ 0 ๐ 0 ๐ฌ 0 ๐ 0๐ Finally online ๐ GRA12, the first identified common virulence factor across Toxoplasma strains and murine subspecies! Check this improved manuscript after reviewersโ helpful suggestions www.nature.com/articles/s41...
16.04.2025 09:57 โ ๐ 26 ๐ 6 ๐ฌ 6 ๐ 2Congratulations Francesca!๐
17.04.2025 20:46 โ ๐ 1 ๐ 0 ๐ฌ 1 ๐ 0Congratulations! Well deserved it
17.02.2025 21:11 โ ๐ 1 ๐ 0 ๐ฌ 1 ๐ 0Delighted to share our study on a major Toxoplasma virulence factor that prevents lytic host cell death.
Many thanks to @parafrap.bsky.social for support, constructive reviews and all labs involved: Melissa Lodoen, Hiba El Hajj, @gissotlab.bsky.social, Karine Le Roch
Link : rdcu.be/d6m3G
Finally, I would like to thank all authors,
@ivanconejeros.bsky.social, and
@moritztreeck.bsky.social for allowing us to work with T.g. HCE1 and MYR1 mutants.
5/Host cells activate the ATM DNA damage response mechanism despite DNA damage. Other genome instability signs found were cytokinesis failure and micronuclei formation, which were observed early during infection. Interestingly, these effects proved independent of MYR1 or HCE1.
#CellBiology
4/ Strikingly, T. gondii-induced DNA damage begins just 15 minutes post-infection. This damage, marked by ฮณH2AX foci, predominantly affects cells in the S-phase and is independent of reactive oxygen species (ROS).
#GenomeInstability
3/ MYR1 drives the translocation of parasite effectors into the host nucleus, leading to cell cycle arrest and a MYR1-dependent DNA damage response. These findings highlight MYR1's central role in parasite-host manipulation.
#DNAResearch #Parasitology
2/ Within 15 minutes of infection, T. gondii causes host cells to arrest in the S-phase of the cell cycle. This rapid effect, seen in endothelial cells, relies on the parasiteโs MYR1 protein but not HCE1.
#CellCycle #HostPathogenInteractions
1/ Toxoplasma gondii manipulates host cells early in infection, arresting the cell cycle and triggering DNA damage. This breakthrough reveals a MYR1-dependent mechanism driving genome instability. Let's dive in!
#ToxoplasmaGondii #ParasiteBiology
๐ฃNew Study Alert!
Toxoplasma gondii arrests host cell cycle early p.i. in a MYR1-dependent manner, inducing DNA damage and genome instability. This work unveils new insights into host-parasite interactions and the mechanisms driving cell cycle modulation.
rdcu.be/d3IxO #Toxoplasma #CellCycle
Schematic showing the experimental outline for a full genome arrayed CRISPR screen. 384-well plates containing cells with an arrayed crRNA library are infected with Cryptosporidium parasites, which undergo asexual rounds of replication intracellularly, followed by sexual development to male and female forms. Plates are then fixed and immunolabeled to detect all parasites, female parasites, host actin recruited to parasite vacuoles, and host nuclei. Three z-stacks were imaged by high content microscopy to detect apically located parasites as well as host cell actin and nuclei.
Have you ever wondered how knocking out every single gene in the human genome, one by one, might affect your intracellular pathogen of interest? We did, & boy was it a wild ride! Happy to share our preprint discovering the essential host genome for Cryptosporidium -
www.biorxiv.org/content/10.1...
Cryptosporidium is an important public health threat, and it deserves better genetic tools to study it! Here weโve developed a targeted in vivo CRISPR genetic screen to identify parasite genes required for survival and virulenceโฆ
www.biorxiv.org/content/10.1...
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Come join us and set up your team in the I2BC Cell Bio Dept!
You will find great science, diverse topics and models, spacious labs, supportive environment, and fun colleagues. We are a short (train) ride south of Paris.
Please DM me with any questions and help us spread the word ๐