Appay is the research director at the INSERM, and co-head of the “Vulnerability and Ageing of the Immune System” team, INSERM U1303 within the ImmunoConcept unit.
After receiving an engineer diploma in Biotechnology at the Ecole Superieure de Biotechnologie de Strasbourg (France) in 1997, he joined the department of Prof Andrew McMichael at the University of Oxford (England) where he obtained a PhD in Immunology in 2001 under the supervision of Prof Sarah Rowland-Jones. Following postdoctoral experiences both in Oxford and Lausanne (Switzerland), he established his research team in Paris (France) in 2005, before moving to Bordeaux in 2020.
Research over the past 25 years has primarily focused on cellular immunity. Early work emphasized the characterization of human T cells in a range of infectious settings, with particular attention to HIV‑1 infection. These studies have contributed mechanistic insights into the generation and function of effective CD8+ T cell responses against HIV, as well as into the role of immune activation in the development of premature immunosenescence during HIV infection. More recently, research activities have increasingly addressed immune ageing in older populations, aiming to advance knowledge within the emerging field of immunogerontology.