Forum d’infectiologie: Dr. Rik L. de Swart (visio-conférence)
Date / Heure
Date(s) - 08/10/2020
11 h 00 min - 12 h 00 min
Forum d’infectiologie: Dr. Rik L. de Swart, (Erasmus MC, Department of Viroscience Rotterdam, The Netherlands): « Measles from an immune suppression : lessons learned from animal models and outbreak studies »
Measles virus (MV) is a highly contagious virus that is transmitted via the respiratory route and causes systemic disease. Measles is characterized by fever and skin rash and is usually associated with cough and conjunctivitis. Hallmark of measles is a transient immune suppression, causing increased susceptibility to opportunistic infections. At the same time, measles is paradoxically associated with induction of a robust virus-specific immune response, resulting in lifelong immunity. While measles lymphopenia lasts for approximately one week, measles immune suppression may last from several weeks to up to more than two years. This led to the initial dismissal of the role of immune cell depletion in causing measles-induced immune suppression. We hypothesized that preferential infection of CD150+ memory lymphocytes causes depletion of these cells that mediate immune responses to previously experienced infections, resulting in immune amnesia. Memory lymphocyte depletion is masked by a massive expansion of MV-specific lymphocytes, which makes the model fully compatible with the measles paradox. We performed an observational cohort study amongst unvaccinated children in the Dutch Orthodox Protestant community during a measles outbreak and showed that viremia in prodromal measles is largely mediated by MV-infected memory lymphocytes. We also showed that measles has a lasting impact on circulating lymphocyte subsets and antibody profiles. These data support our immune amnesia hypothesis and may explain the long-term effects of measles on host resistance.
Hôte : Mathieu Mateo