The persistence of memory: A unique niche for IgG memory B cells

The persistence of memory: a unique niche for IgG memory B cells.

T he concept of immunologic memory has been documented since ancient times. Indeed, in 450 BC, the Greek historian Thuydices observed that those who had survived a disease were most apt to visit the newly stricken, because “[they] knew it was from experience, and had now no fear for themselves, for the same man was never attacked twice.” Despite this longstanding appreciation, the mechanisms re...

Autoreactivity in human IgG+ memory B cells.

More than half of the nascent B cells in humans initially express autoreactive antibodies. However, most of these autoantibodies are removed from the repertoire at two checkpoints before maturation into naive B cells. A third checkpoint excludes remaining autoantibodies from the antigen-experienced IgM(+) memory B cell pool. Nevertheless, low-affinity self-reactive antibodies are frequently fou...

Cellular Dynamics of Memory B Cell Populations: IgM+ and IgG+ Memory B Cells Persist Indefinitely as Quiescent Cells.

Despite their critical role in long-term immunity, the life span of individual memory B cells remains poorly defined. Using a tetracycline-regulated pulse-chase system, we measured population turnover rates and individual t1/2 of pre-established Ag-induced Ig class-switched and IgM-positive memory B cells over 402 d. Our results indicate that, once established, both IgG-positive and less freque...

Reactivation of IgG-switched memory B cells by BCR-intrinsic signal amplification promotes IgG antibody production

Secondary antibody responses are marked by faster kinetics, improved antibody affinity and a switch from IgM to other immunoglobulin isotypes, most notably IgG, compared with primary responses. These changes protect from reinfection and represent the principle of most vaccination strategies. Yet, the molecular mechanisms that underlie B-cell memory responses are unclear. Here we show, by inacti...

The Persistence of Memory