0000000000350186
AUTHOR
Salvatore Vitello
B cell immunosenescence in the elderly and in centenarians.
The elderly suffer from an increased susceptibility to infectious disease and cancer. Aging of the immune system contributes to this state of affairs due to immunosenescence. Because repeated intermittent or chronic antigen exposure may lead to lymphocyte clonal exhaustion, chronic antigenic stress plays a part in the compromised immunity of the elderly, who have accumulated a lifetime's exposure to infectious agents, autoantigens, and cancer antigens. Literature on immunosenescence has focused mainly on T cell impairment, but B cell compartment is also affected. The age-dependent B cell changes documented by the present review indicate that advanced age per se is a condition characterized …
B cell immunosenescence: different features of naive and memory B cells in elderly.
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…
Memory B Cell Subpopulations in the Aged
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…
Impairment of gamma/delta T lymphocytes in elderly: implications for immunosenescence
Gamma/delta T lymphocytes cells recognize the antigen in a non-classical way and are considered the third branch of the immune system devoted to defend the integrity of the body. Ageing is characterized by an impairment of the main way of protection (the adaptive branch) but, successfully aged people show compensatory mechanisms of defense such as proneness to inflammation. Moreover, very old subjects show an increased number of NK cells. We have previously demonstrated that gamma delta T lymphocytes are reduced in elderly. In the present paper we have studied some characteristics of these cells to evaluate the possibility that these cells might balance the decreased action of the adaptive …
A double-negative (IgD−CD27−) B cell population is increased in the peripheral blood of elderly people
The T cell branch of the immune system has been extensively studied in the elderly and it is known that the elderly have impaired immune function, mainly due to the chronic antigenic load that ultimately causes shrinkage of the T cell repertoire and filling of the immunologic space with memory T cells. In the present paper, we describe the IgD(-)CD27(-) double-negative B cell population which (as we have recently described) is higher in the elderly. Most of these cells were IgG(+). Evaluation of the telomere length and expression of the ABCB1 transporter and anti-apoptotic molecule, Bcl2, shows that they have the markers of memory B cells. We also show that these cells do not act as antigen…