1974-1978, DERBH student, then Collège de France Fellowship, INSERM U.20, Hospital Broussais, Paris, Director Pr. Bernard Halpern
1978-1982, PhD. student (LNFCC and ARC Fellowships), INSERM U.50, ICIG, Villejuif, Director Pr. Raymond Frade
1982-1986, Attaché de Recherches INSERM, INSERM U.139, Hospital Henri Mondor, Créteil, Director Raymond Frade
1986-1991, Chargé de Recherche INSERM, INSERM U.23, Hospital Saint-Antoine, Paris, Director Raymond Frade
Since July 1991, Director of research INSERM
1991-2005, INSERM U.354, at Hospital Saint-Antoine, Paris (until 2002), then Genopole at Evry, Director Raymond Frade
Since July 2005, INSERM U.570, now U.1002, University René Descartes, Faculty Necker –Enfants Malades, Paris, Director Pr. Xavier Nassif
Since 1998, my main interest has been the study of host-pathogen interaction. Until 2005, I analyzed the interaction of Epstein-Barr virus (EBV), involved in human B lymphoma, with its receptor on human B lymphocytes, the complement receptor type 2 (CR2). I first studied its binding characteristics. Then, I showed that EBV binding on CR2 triggered intracellular signalling through different pathways. One of the human intracellular protein involved was nucleolin, a protein known previously to be localized only in nucleus but described now as able to shuttle from the nucleus to the cell membrane. Since 2005, I am interested in the infection of human macrophages by the pathogenic bacteria, Francisella tularensis. These bacteria are responsible for the human disease, tularemia and are now considered as a potential biothreat terrorism agent, due to their ability to infect humans at very low doses by simple inhalation. I recently demonstrated that nucleolin, present on the surface of human macrophages, is involved in the binding of Francisella tularensis through its elongation factor Tu, present on the surface of the bacteria. This function of nucleolin is specific to Francisella tularensis as it was not used either by Listeria monocytogenes or inert particles. Nucleolin is also involved in the infection of the human cells by these bacteria. Therefore, nucleolin may serve as a cargo protein for the bacteria as they are endocytosed together with this protein. I recently demonstrated that an amino acid transporter (SLC1A5) is upregulated by Francisella tularensis infection, both at the mRNA and at the protein level. Furthermore, this transporter is specifically deglycosylated by Francisella infection and not by Listeria infection. This deglycosylation may provide nutrients for survival of the bacteria inside the human cells.
Altogether, these results show that pathogens are able to use eukaryotic proteins, localized either on the cell surface or intracellularly to subvert host defense.