T-bet+ B cells are activated by and control endogenous retroviruses through TLR-dependent mechanisms. - Rauch E; Amendt T; Lopez Krol A; Lang FB; Linse V; Hohmann M; Keim AC; Kreutzer S; Kawengian K; Buchholz M; Duschner P; Grauer S; et al. (Nature communications, 2024)