Preferential localization of IgG memory B cells adjacent to contracted germinal centers

Abstract

It has long been presumed that after leaving the germinal centers (GCs), memory B cells colonize the marginal zone or join the recirculating pool. Here we demonstrate the preferential localization of nitrophenol-chicken γ-globulin-induced CD38+IgG1+ memory B cells adjacent to contracted GCs in the spleen. The memory B cells in this region proliferated after secondary immunization, a response that was abolished by depletion of CD4+ T cells. We also found that these IgG1+ memory B cells could present antigen on their surface, and that this activity was required for their activation. These results implicate this peri-GC region as an important site for survival and reactivation of memory B cells.