Postdoc position in my group at the Institut Pasteur in Paris in the field of cell and tissue biology and host-pathogen interactions!

We are delighted to announce that our Colox Project has received funding from the ANR!

We are hiring two postdoctoral researchers at the Institut Pasteur in Paris.

One of them will be hired for a period of 36 months to join my group https://research.pasteur.fr/en/team/group-nathalie-sauvonnet/ So please don’t hesitate to send me your application by mail [email protected]!

Here is a summary of our project:

Impact of Oxygen on the Human Colonic Barrier Under Physiological and Infectious Conditions

The human colon maintains a steep oxygen (O₂) gradient, shaped by epithelial and microbial metabolism, which is essential for barrier integrity and sustaining an anaerobic microbiota. During infection, this balance is disrupted, causing barrier dysfunction, dysbiosis, pathogen expansion, and immune activation. How the O₂ gradient influences epithelial cell fate, mucus properties, and immune responses during infection remains poorly understood. Clostridioides difficile (CD), an anaerobic pathogen, thrives in low-O₂ environments and triggers massive neutrophil recruitment; however, the interplay between O₂, CD, and host immunity remains unclear.

The ColOx project aims to define the role of O₂ levels in the human colonic barrier under physiological and infectious conditions by exposing the system to CD infection and neutrophils. The project’s objectives are to determine:

1- Mapping of O₂ concentrations in a human colon-on-chip under various O₂ concentration conditions

2- Impact of O2 variation on the epithelial and mucus layers under physiological conditions

3- Impact of the O2 gradient on the colonic barrier under conditions of infection using CD as a challenger

4- Impact of Hypoxia on the Interaction Between CD and Neutrophils

By integrating patient-derived colonic organoids, endothelial and immune cells into an organ-on-a-chip By exposing devices to controlled O₂ environments, ColOx enables causal studies of epithelial, microbial, and immune interactions. Using an interdisciplinary approach—including real-time O₂ mapping, transcriptomic analyses, mucus characterization, CD infection assays, and neutrophil functional studies—ColOx will generate novel insights into how O₂ regulates barrier function and host–microbe dynamics in health and disease.