Thierry JAFFREDO Origins and Regulations of hematopoietic stem Cells

Course and current status

PhD degree in 1989 at the University Pierre et Marie Curie (UPMC), Paris following a work on oncogenes and development at the “Institut d’Embryologie de Nogent sur Marne” headed by Pr. Nicole le Douarin in the team of Dr. Françoise Dieterlen. Post-doc at the Institut Pasteur, Lille. After a few years as CNRS CRCN (1991) at Nogent-sur-Marne I moved to Sorbonne Université (formerly UPMC) in 2002 where I established my own group. Director of Research 2 in 2005, Director of research 1 in 2014, Deputy director of the CNRS UMR7622 unit since 2017.

Scientific summary

My research is focusing on hematopoietic stem cell development using avian, mouse and human embryo models with a special interest to the interactions between haematopoietic stem cells and their niches. I was among the first to demonstrate that haematopoietic production in the embryonic aorta was occurring from hemogenic endothelial cells (Jaffredo et al., 1998) and was able to trace the progeny of the hemogenic endothelium using non-replicative retroviral vectors (Jaffredo et al., 2000). I also demonstrated the role of the allantois as a new hematopoietic organ in birds (Caprioli et al., 1998; 2001). I explored the dynamics of endothelium in the aorta, the role of the somites and the transient production of haematopoiesis associated with the exhaustion of the hemogenic endothelium. I also showed that the somite was giving rise to smooth muscle cells of the aorta (Pouget et al., 2006; 2008). Regarding Runx1, the hallmark of hemogenic endothelium, I demonstrated that its expression in the aorta was triggered by the formation of the sub-aortic mesenchyme (Richard et al., 2013). In recent years, I developed systems biology approaches to identify gene networks operating during haematopoietic stem cell-niche cell interactions (Charbord et al., 2014) and showed the role of extracellular vesicles in the hematopoietic support (Stik et al., 2016). I developed a robust in vitro system recapitulating the endothelial to haematopoietic transition (Yvernogeau et al., 2016) and demonstrated the existence of a haemogenic endothelium in the late foetal/young adult bone marrow in birds and mammals (Yvernogeau et al., 2019). I am now implementing new strategies to study cellular and molecular interactions in the leukemic niche. As a stem cell scientist and developmental biologist, I have organised several international meetings on stem cells over the past years covering different areas of the stem cell field. I have served as task force delegate for the ISEH and I’m involved in the organisation and writing of the “European Hematology Association Roadmap for European Research” to promote Haematology research through Europe. I am serving as board member of the French Society for Stem Cell Research.

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