1/4 What if in vivo apoptotic cell fragmentation is not autonomous, but is carried out by resident phagocytes? Check how this can improve tissue clearance in our recent paper from the Hoijman and Poon labs. @ibmb-csic.bsky.social @latrobeuni.bsky.social
www.science.org/doi/10.1126/...

4/4 We found this mechanism using early zebrafish embryos and mouse thymuses. It may help avoid inflammation during homeostatic or developmental cell turnover.

3/4 Both fragmentation and phagocytosis are size-sensitive, with small targets favoring phagocytosis and large targets favoring fragmentation. Therefore, reducing apoptotic cell size by phagocyte-mediated fragmentation improves the efficiency of tissue clearance.

2/4 Assumed to be intrinsic to apoptotic cells, fragmentation into apoptotic bodies can be performed by Actin-rich protrusions from phagocytic cells, which split apoptotic cells into smaller phagocytic targets.

1/4 What if in vivo apoptotic cell fragmentation is not autonomous, but is carried out by resident phagocytes? Check how this can improve tissue clearance in our recent paper from the Hoijman and Poon labs. @ibmb-csic.bsky.social @latrobeuni.bsky.social
www.science.org/doi/10.1126/...

Want to image cells protecting the embryo during early development? We're hiring! 1 Postdoc, 1 PhD student, and 1 Research Technician. Come to Barcelona! www.embryobioimaging.com

Haciendo contacto: nuestro primer encuentro con los habitantes del micromundo Un hallazgo clave para entender la fertilidad y la salud reproductiva: un embrión es capaz de defenderse de bacterias.

Mi artículo @muyinteresante.com sobre el primer encuentro entre embriones humanos y bacterias
www.fundacionmuyinteresante.org/embrion-defe...

Thanks for the comment of our paper in @science.org . Our first encounter in development with other organisms.

Early embryos develop... and eliminate threats - the Node We recently discovered that early embryos can eliminate bacterial infections before immune cells are formed. Take a look at the dynamics of our first encounter with microbes.

Now at The Node
Early embryos develop... and eliminate threats thenode.biologists.com/early-embryo...

Thanks for the comment of our paper in @science.org . Our first encounter in development with other organisms.

Thanks Hanna!

Thanks Juan!

Thanks!

Thanks!!

Thanks Alejo!!

Thanks Marta!

Thanks!

Thanks!!

Thanks Marc!

Thanks!

Thanks!!

Our work highlights the urgent need to better define bacterial populations able to colonize or reside in the human uterus and to increase visibility of infection-related uterine diseases and their possible link to infertility. 9/9

Our work reveals that, beyond proliferation, fate specification, tissue morphogenesis, and implantation, early embryonic cells also play biological defense roles well before organ formation. 8/9

Functional experiments with engineered bacteria show that phagocytic clearance improves normal developmental progression after infection, emphasizing its key defensive role. 7/9

Transcriptomic analysis after bacterial challenge showed that epithelial cells activate a full set of immune genes regulated by NF-κB, including proinflammatory cytokines, antibacterial proteins, and pattern recognition receptors. 6/9

Quantitative imaging and in vivo single-cell interference revealed the dynamics and key regulators of phagocytic protrusions for bacterial internalization, still poorly understood in immune cells. We also identified tissue-scale patterns shaped by bacterial motility. 5/9

We also modeled these infections in early zebrafish embryos, enabling us to observe bacterial clearance dynamics by epithelial cells across scales—from subcellular to tissue-level behaviors. 4/9

Since bacterial infections are common in the human uterus, we asked how preimplantation embryos respond to microorganisms. We found that, long before myeloid immune cells develop, human embryos phagocytose and destroy certain bacteria infecting the uterus, such as S. aureus. 3/9

@joanroncero

Extraordinary achievement of Joan Roncero, a talented PhD student who tackled every challenge, with key contributions from June Olaizola. Thanks also to Irimia Lab @crg.eu, Veiga Lab @idibell.bsky.social, Torrents & Ojosnegros Labs @ibecbarcelona.eu, Miquel Solé @dexeus, and Alsina Lab @upf.edu 2/9

Our paper is now published! The first encounter of a forming organism with bacteria reveals that innate immunity initiates in epithelial cells of early embryos, even in humans. www.cell.com/cell-host-mi...
made in @ibmb-csic.bsky.social @csic.es @idibell.bsky.social 1/9