title: B cell immunosenescence: different features of naive and memory B cells in elderly.
abstract: Elderly people show a reduced protection against new infections and a decreased response to vaccines as a consequence of impairment of both cellular and humoral immunity. In this paper we have studied memory/naïve B cells in the elderly, evaluating surface immunoglobulin expression, production of the pro- and anti-inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-10, and presence of somatic hypermutation, focusing on the IgG(+)IgD(-)CD27(-) double negative (DN) B cells that are expanded in the elderly. Our results show that naïve B cells from young donors need a sufficiently strong stimulus to be activated "in vitro", while naïve B cells from old subjects are able to produce IL-10 and TNF-α when stimulated "physiologically" (α-CD40/IL-4), suggesting that these cells might play a role in the control of the immuno-inflammatory environment in the elderly. In addition, in the elderly there is an accumulation of DN B cells with a reduced rate of somatic hypermutation. Thus, DN B lymphocytes may be exhausted cells that are expanded and accumulate as a by-product of persistent stimulation or impaired germinal center formation.
authors: Immunosenescence Unit, Department of Pathobiology, University of Palermo, Corso Tukory, 211, 90134, Palermo, Italy.
authors: Silvio
authors: S
authors: Buffa
authors: Matteo
authors: M
authors: Bulati
authors: Mariavaleria
authors: M
authors: Pellicanò
authors: Deborah K
authors: DK
authors: Dunn-Walters
authors: Yu-Chang
authors: YC
authors: Wu
authors: Giuseppina
authors: G
authors: Candore
authors: Salvatore
authors: S
authors: Vitello
authors: Calogero
authors: C
authors: Caruso
authors: Giuseppina
authors: G
authors: Colonna-Romano
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D016922:Cellular Senescence / Q000276:immunology*; D006801:Humans; D007136:Immunoglobulins / Q000276:immunology; D007156:Immunologic Memory; D016753:Interleukin-10 / Q000096:biosynthesis; D015759:Ionomycin / Q000494:pharmacology; D008213:Lymphocyte Activation; D008875:Middle Aged; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D007136:Immunoglobulins; D016753:Interleukin-10; D015759:Ionomycin; D013755:Tetradecanoylphorbol Acetate