Persistent antigen and germinal center B cells sustain T follicular helper cell responses and phenotype.
Baumjohann D, Preite S, Reboldi A, Ronchi F, Ansel KM, Lanzavecchia A, Sallusto F. Persistent antigen and germinal center B cells sustain T follicular helper cell responses and phenotype. Immunity. 2013 Mar 21; 38(3):596-605.