• Chef de projet: Jules Brice Tchatchueng Mbougua, Centre Pasteur du Cameroun / UMMISCO, Cameroun
• Durée du projet: 24 Months
• Date de début: February 2021

• ANR 2023: INRIA, INRAE et IRD 
• Participants UMMISCO: G. Sallet et B. Cazelles (Correspondant IRD et Responsable WP1)
• Durée du projet: 36 months
• Date début du projet: Janvier 2024
• Budget total: 350K€

his project is a part of the international Infect-Era program, AMOEBAC: Entamoeba histolytica-bacterium interaction and the role of this interaction in intestinal pathogenesis (http://www.infect-era.eu/2nd-call-2014)

The aim of this investigation is to understand the induced changes in physiology, metabolism, and gene expression of Entamoeba histolytica following its interaction with enteric bacteria and during intestine invasion. We take advantage of human tissue-like models to study amoebic pathogenesis combining imaging, image analysis and Omics approaches. The three-dimensional tissue model consists of a human cells system composed of fibrillar collagen I matrix, intestinal cells (epithelial, fibroblasts and goblets) and macrophages. Using this model, we determine the rate of amebic invasiveness using two-photon laser scanning fluorescence microscopy, assess the immune response using ELISA, investigate human gene expression by RNA sequencing and discover the secretome using proteomics and HPLC-MS/MS.

In the human colon, mucus protects the underlying epithelium from pathogens. During infection, pathogens and resident microbiota compete for nutritional metabolites and therefore changes may alter the equilibrium in the colon ecosystem contributing to the susceptibility to infection. Around 50–60 % of the population in developing countries might be harboring E. histolytica in the outer mucus layer in an asymptomatic manner. Only ∼20% of the cases develop intestinal amoebiasis and thus under conditions not fully understood. E. histolytica overcomes the protective mucus layer using a combination of mucinase/glycosidase and cysteine proteases. Actually, publications of study on the field and in vitro suggest that the outcome of amoebiasis may be influenced by the composition of the gut microbiome.

– In this project, we aim at studying the impact of the mucus colonised with different commensal bacteria (in collaboration with H. Tun) on the mechanic of the epithelium and on E. histolytica behaviour using human organoid-derived colonic epithelial cells (in collaboration with G. Nigro) cultured in an organ-on-a-chip microfluidic device (in collaboration with the microfluidics plateform. S. Gobaa and H. Mary).
– By live imaging and quantitative image we will measure the stress maps within the tissue using an integrated framework to analyze cell mechanics and we will qualify E. histolytica behavior.