Search results for "memory B cells"
showing 5 items of 5 documents
B cell immunosenescence: different features of naive and memory B cells in elderly.
2011
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/naive 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 naive B cells from young donors need a sufficiently strong stimulus to be activated "in vitro", while naive B cells from old subjects are able t…
CD27 distinguishes two phases in bone marrow infiltration of splenic marginal zone lymphoma.
2004
Aims: To investigate CD27 expression in splenic marginal zone lymphoma (SMZL), an indolent low-grade B-cell lymphoma with constant involvement of the bone marrow, especially with an intrasinusoidal pattern. It is not clear if the neoplastic clone is composed of virgin or somatically mutated B cells. CD27 is reported to be a hallmark of memory B cells. Methods and results: We evaluated 64 bone marrow biopsy specimens (BMBs) from 36 patients with SMZL for the expression of CD27. For comparison, splenectomy specimens of patients with traumatic splenic rupture or with SMZL were used. All BMBs showed lymphomatous infiltration. When located in the marrow sinusoids, neoplastic cells were CD27– i…
Memory B Cell Subpopulations in the Aged
2006
The literature on immunosenescence has focused mainly on T cell impairment. With the aim of gaining insight into B cell immunosenescence, the authors investigated the serum IgD levels in 24 young and 21 old people and analyzed their relationship with the number of CD19 CD27 memory cells. Serum IgD were quantified by the use of radial immunodiffusion and the lymphocyte population CD19 CD27 was identified by a FACScan flow cytometer. Serum IgD levels were significantly lower (p 0.0001) in old subjects, and the percentage of CD19 CD27 lymphocytes were significantly increased (p 0.01) in old subjects. Finally, a significant negative correlation was found (p 0.01) between serum concentrations of…
Reduced CD27−IgD− B Cells in Blood and Raised CD27−IgD− B Cells in Gut-Associated Lymphoid Tissue in Inflammatory Bowel Disease
2019
The intestinal mucosa in inflammatory bowel disease (IBD) contains increased frequencies of lymphocytes and a disproportionate increase in plasma cells secreting immunoglobulin (Ig)G relative to other isotypes compared to healthy controls. Despite consistent evidence of B lineage cells in the mucosa in IBD, little is known of B cell recruitment to the gut in IBD. Here we analyzed B cells in blood of patients with Crohn's disease (CD) and ulcerative colitis (UC) with a range of disease activities. We analyzed the frequencies of known B cell subsets in blood and observed a consistent reduction in the proportion of CD27−IgD− B cells expressing all Ig isotypes in the blood in IBD (independent o…