Biology subjects

Gros, G.

Publications and source records attributed to Gros, G..

4 recordsLinked to original sources

bioRxiv2025

IL-26 from ILCs regulates early-life gut epithelial homeostasis by shaping microbiota composition

Animals host symbiotic microbial communities that shape gut health. However, how the host immune system and microbiota interact to regulate epithelial homeostasis, particularly during early development, remains unclear. Human interleukin-26 (IL-26) is associated with gut inflammation and has intrinsic bactericidal activity in vitro, yet its in vivo functions are largely unknown, primarily due to its absence in rodents. To examine the role of IL-26 in early life, we used zebrafish and found that gut epithelial cells in il26-/- larvae exhibited increased proliferation and DNA damage, faster turnover, and an altered abundance of cell populations. This epithelial dysregulation occurred independently of the IL-26 canonical receptor and resulted from dysbiosis in il26-/-. Moreover, IL-26 bactericidal activity was conserved in zebrafish. Our findings suggest that IL-26 directly regulates microbiota composition through this property. We further identified innate lymphoid cells (ILCs) as the primary source of IL-26 at this developmental stage. These findings establish IL-26 as a central player in a regulatory circuit linking the microbiota, ILCs, and intestinal epithelial cells to maintain gut homeostasis during early life.

immunology↗

bioRxiv2025

Interleukin-22 in enteroendocrine cells controls early-life gut motility through interactions with the microbiota

The gut microbiota, immune system, and enteric nervous system tightly interact to regulate adult gut physiology. Yet the mechanisms establishing gut physiology during development remain unknown. Here, we report that in developing zebrafish, enteroendocrine cells produce IL-22 in response to microbial signals before lymphocytes populate the gut. In larvae, IL-22 is crucial to set gut microbiota composition, and ghrelin hormone expression to promote gut motility. IL-22 developmental function depends on its ability to modulate gut microbiota, as bacterial transfer from wild-type zebrafish restored gut motility in il22-/- by reestablishing ghrelin hormone expression. Additionally, IL-22-deficient mice show impaired gut motility and reduced ghrelin expression in early life, indicating a conserved function. Altogether, we identify a circuit where enteroendocrine cells regulate gut function via cytokine control of the microbiota, showing how gut physiology is set prior to immune system maturation.

immunology↗

bioRxiv2023

A non-invasive photoactivatable split-Cre recombinase system for genome engineering in zebrafish.

The cyclic recombinase (Cre)/loxP recombination system is a powerful technique for in vivo cell labeling and tracking. However, achieving high spatiotemporal precision in cell tracking using this system is challenging due to the requirement for reliable tissue-specific promoters. In contrast, light-inducible systems offer superior regional confinement, tunability and non-invasiveness compared to conventional lineage tracing methods. Here, we took advantage of the unique strengths of the zebrafish to develop an easy-to-use highly efficient, genetically encoded, Magnets-based, light-inducible transgenic Cre/loxP system. Our system relies on the reassembly of split Cre fragments driven by the affinity of the Magnets and is controlled by the zebrafish ubiquitin promoter. We demonstrate that our system does not exhibit phototoxicity or leakiness in the dark, and it enables efficient and robust Cre/loxP recombination in various tissues and cell types at different developmental stages through noninvasive illumination with blue light. Our newly developed tool is expected to open novel opportunities for light-controlled tracking of cell fate and migration in vivo. HighlightsO_LIzPA-Cre is a novel zebrafish transgenic optogenetic split-Cre tool C_LIO_LIzPA-Cre allows loxP-mediated DNA recombination in various tissues and cell types C_LIO_LIIt enables light-induced DNA recombination at different developmental stages. C_LIO_LIIt allows spatio-temporal DNA recombination in a specific tissue region with high resolution C_LI

developmental biology↗

bioRxiv2023

A layered erythromyeloid ontogeny ensures timely supply of erythrocytes and macrophages during development

In all organisms studied, from flies to humans, blood cells emerge in several sequential waves and from distinct hematopoietic origins. However, the relative contribution of these ontogenetically distinct hematopoietic waves to embryonic blood lineages and to tissue regeneration during development is yet elusive. Here, using a lineage-specific switch and trace strategy in the zebrafish embryo, we report that the definitive hematopoietic progeny barely contributes to erythrocytes and macrophages during early development. Lineage tracing further show that ontogenetically distinct macrophages exhibit differential recruitment to the site of injury based on the developmental stage of the organism. We further demonstrate that primitive macrophages can solely maintain tissue regeneration during early larval developmental stages after selective ablation of definitive macrophages. Our findings highlight that the sequential emergence of hematopoietic waves in embryos ensures the abundance of blood cells required for tissue homeostasis and integrity during development. O_FIG O_LINKSMALLFIG WIDTH=145 HEIGHT=200 SRC="FIGDIR/small/529211v2_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@c4cd30org.highwire.dtl.DTLVardef@7b38deorg.highwire.dtl.DTLVardef@1d28ea9org.highwire.dtl.DTLVardef@940784_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗