B cells and immunosenescence: A focus on IgG+IgD−CD27− (DN) B cells in aged humans

B cells and immunosenescence: a focus on IgG+IgD-CD27- (DN) B cells in aged humans.

Immunosenescence contributes to the decreased ability of the elderly to control infectious diseases, which is also reflected in their generally poor response to new antigens and vaccination. It is known that the T cell branch of the immune system is impaired in the elderly mainly due to expansion of memory/effector cells that renders the immune system less able to respond to new antigens. B lym...

Cells in Aged Mice and Humans Mechanisms for Decreased Function of B

Mechanisms for decreased function of B cells in aged mice and humans.

The immune system has been known for some time to be compromised in aged individuals, e.g., both mice and humans, and in both humoral and cellular responses. Our studies have begun to elucidate intrinsic B lymphocyte defects in Ig class switch recombination, activation-induced cytidine deaminase, and E47 transcription factor expression. These defects occur in both mice and humans. Our studies h...

CD26+ Cord Blood Mononuclear Cells Significantly Produce B, T, and NK Cells

Background: Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cell transplantation (HSCT), used in Leukemia treatment. CD26+ cells, a fraction of CD34 positive cells, are a major population of UCB cells which negatively regulate the in vivo homing and engraftment of HSCs. CD26 is highly expressed in various cells such as HSCs, immune cells, fibroblasts, and epithelial ce...

Distribution of Circulating Immune Cells in Responder and Non-Responder Individuals to Hepatitis B Vaccine

Unresponsiveness to hepatitis B surface antigen (HBsAg) has been shown to be associated with dysfunction of the presenting cells (APC) and defect in the specific B-lymphocyte and/or T-lymphocyte repertoires.   Direct determination of the frequency of specific T-lymphocytes together with complementary analysis of the naive circulating immune cells could provide valuable information about the cel...