Séminaire CIRI: Mathieu IAMPIETRO
Date / Heure
Date(s) - 13/12/2017
11 h 00 min - 12 h 00 min
Amphi Pasteur, Tour CERVI
Mathieu IAMPIETRO (University of Texas Medical Branch, Galveston National Laboratory – USA): « Disabling of T-lymphocyte immune response by Ebola Virus »
Ebola Virus Disease (EVD) is characterized by a rapid evolution leading to a sepsis-like syndrome that is associated with low counts of immune cells and particularly lymphopenia, which is uniformly observed in all fatal cases. Nonetheless, the mechanisms by which EBOV rapidly overpowers the host’s immune responses remain largely unknown. In our studies, we demonstrated that despite an absence of productive infection, Ebola virus directly binds to T-lymphocytes. We show that membrane bound virions are rapidly internalized and co-localize with endosomal markers. Specifically, Ebola glycoprotein (GP) interaction with TLR4 and/or viral membrane associated phosphatidylserine (PS) with Tim-1 on the surface of T-cells result in increased cytokine production consistent with non-specific activation and an overall contribution to the onset of a cytokine storm. Overall, these interactions resulted in a significant increase in cell death, which may contribute to the lymphopenia observed in vivo.
Contact : Branka Horvat