Memory B cells isolated from human tonsils are characterized by an activated cell surface phenotype, localization to mucosal epithelium, expression of somatically mutated immunoglobulin (Ig) variable (V) region genes, and a preferential differentiation into plasma cells in vitro. In spleens of both humans and rodents, a subset of memory B cells is believed to reside in the marginal zone of the ...

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 gamma-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 res...

background & aim: in traditional medicine, boswellia species gum resin known as frankincense or olibanum, has been administrated in elderly for enhancement of memory and also in pregnant women to increase memory and intelligence of progeny. however, it has been rarely scientifically documented so far. we have previously reported that maternal administration of frankincense during lactation ...

Considering the emerging importance of phenotypic markers as indicators of cell function and differentiation, we studied patterns ofCD44 and CD45RB expression in CD8+ murine T cells with prior exposure to antigen or staphylococcal enterotoxin B ( SEB ). Following in vivo priming with two purified protein derivatives (one from a virulent WHO strain and the other from an avirulent strain), T ...

Induction of tolerance in memory T cells has profound implications in the treatment of autoimmune diseases and transplant rejection. Previously, we reported that the presentation of low densities of agonist peptide/MHC class II complexes induced anergy in memory CD4(+) T cells. In the present study, we address the specific interaction of different types of APCs with memory CD4(+) T cells. A nov...

The humoral immune system has the ability to acquire memory. Hence, it can recall a previous encounter with an antigen and consequently mount a efficient, specific, and rapid response to a second challenge by that same antigen. A critical aspect of this acquisition of memory is the establishment of a small pool of memory B cells during the latter phases of the primary immune response. In mice a...

abstract background b cells play an important role in the immune system due to production of the immunoglobulin and secreting several cytokines. it has been shown that b cells produced successfully in the presence of stem cell factor (scf) and flt3 ligand (flt3l). il2, il7, and il15 cytokines as  -common family have an essential cytokines may support either synergistically or in an additi...

INTRODUCTION HIV causes defects in memory B cells in children, but the mechanisms of those defects have not been fully elucidated. One possible mechanism is the lack of T-cell help to B cells during immune reactions. However, few studies have assessed the effect of HIV on follicular helper T cells (TFH cells) in children. METHODS In this study, follicular-homing CD4 T cells and memory B cells...

The expression of the costimulatory molecules CD80 and CD86 was increased on synovial fluid CD19+ B cells as compared to peripheral blood. CD80/CD86 expression on these B cells could be shown to induce alloreactive T cell proliferation in vitro. Most of the synovial fluid B cells belonged to the CD27+IgDclass-switched memory B cell subset. However, almost half of the CD27 negative synovial B ce...

Memory B cells are a central component of humoral immunity, and yet little is known about their longevity in humans. Immune memory after smallpox vaccination (DryVax) is a valuable benchmark for understanding the longevity of B cell memory in the absence of re-exposure to Ag. In this study, we demonstrate that smallpox vaccine-specific memory B cells last for >50 years in immunized individuals....