RT Journal Article SR Electronic T1 Maintenance of Serological Memory by Polyclonal Activation of Human Memory B Cells JF Science JO Science FD American Association for the Advancement of Science SP 2199 OP 2202 DO 10.1126/science.1076071 VO 298 IS 5601 A1 Bernasconi, Nadia L. A1 Traggiai, Elisabetta A1 Lanzavecchia, Antonio YR 2002 UL http://science.sciencemag.org/content/298/5601/2199.abstract AB Production of antibodies can last for a lifetime, through mechanisms that remain poorly understood. Here, we show that human memory B lymphocytes proliferate and differentiate into plasma cells in response to polyclonal stimuli, such as bystander T cell help and CpG DNA. Furthermore, plasma cells secreting antibodies to recall antigens are produced in vivo at levels proportional to the frequency of specific memory B cells, even several years after antigenic stimulation. Although antigen boosting leads to a transient increase in specific antibody levels, ongoing polyclonal activation of memory B cells offers a means to maintain serological memory for a human lifetime.