Séminaire CIRI : Dr. Timothée Bruel

Dr. Timothée BRUEL (Institut Pasteur, Unité Virus et Immunité, Paris), "Antiviral activities of anti-HIV-1 and anti-SARS-CoV-2 antibodies".

Abstract: Antibodies are produced by B cells as part of immune responses. They are polyfunctional
molecules, recognizing foreign molecular motifs through their variable domains and
interacting with immune cells via their constant region (Fc region). Our goal is to unravel the
landscape of antiviral activities of antibodies and underlying mechanisms in the context of
HIV-1 and SARS-CoV-2 infections.
Recombinant broadly neutralizing antibodies (bNAbs) targeting the HIV-1 envelope
glycoprotein (Env) are promising molecules for therapeutic or prophylactic interventions. We
have characterized their capacity to eliminate infected cells by NK-mediated antibodydependent cellular cytotoxicty (ADCC) and complement activation. We have also identified
an additional antiviral activity of bNAbs, which block HIV-1 release by tethering viral particles
at the surface of infected cells. In the context of SARS-CoV-2, we have developed a pipeline
to isolate circulating viral strains and investigate their profile of neutralization by sera from
convalescent and vaccinated individuals, as well as therapeutic antibodies. We also set-up
assays to quantify ADCC of SARS-CoV-2 infected cells and used them to investigate the
immune responses of asymptomatic individuals.
Overall, our projects aim at providing a basic understanding of antibody polyfunctionality and
viral countermeasures, with implications for the development of the next generations of
antibody-based vaccines and therapies