0000000000149637
AUTHOR
Marcella Potestio
Age-related changes in the expression of CD95 (APO1/FAS) on blood lymphocytes☆
Abstract Aging is associated with alterations of the immune system, thought to be related to an increased susceptibility to infectious diseases, and possibly to cancer and autoimmunity in the elderly. In the present paper we report data obtained on freshly collected blood from 148 healthy subjects of different ages (from cord blood to 102 years old). The subjects were divided into seven age classes (cord blood, 3–11 years, 15–39 years, 41–60 years, 61–74 years, 75–84 years, 85–102 years) and their lymphocyte subsets and the expression of the apoptosis-related molecule CD95 were evaluated. In respect of lymphocyte subsets, the major differences were found in the cord-blood samples compared w…
Apoptosis and ageing.
Stimulation of T cells from aged individuals leads to different kinds and/or size of responses if compared with the responses of T cells obtained from young individuals. In fact elderly is associated with a progressive decline of immune response besides an increasing incidence of autoimmune phenomena. These differences might be the result of modified cellular mechanisms controlling the immune system in the course of ageing. The apoptotic deletion of activated T cells has been proposed as the key mechanism to maintain T cell homeostasis, and in this respect CD95 (Fas antigen) seems to play a major role in this course of events. In this study we show that just collected lymphocytes from old s…
Gamma/delta T lymphocytes are affected in the elderly
gammadelta T lymphocytes are considered to represent a link between the inflammatory response and adaptive immunity. In the present paper we investigated whether these cells play any role in the remodeling of the immune system described in the elderly. We show that the absolute number of gammadelta T cells in peripheral blood of old and very old subjects is reduced. Moreover, gammadelta T cells from old people and centenarians show enhanced levels of the early activation marker CD69 both after culture in medium alone and in LPS-stimulated cells. Furthermore, they show a basal increased production of tumor necrosis factor (TNF)-alpha as evaluated at the single cell level. Additionally, the r…
CD4+ CCR5+ and CD4+ CCR3+ lymphocyte subset and monocyte apoptosis in patients with acute visceral leishmaniasis
The potential involvement of apoptosis in the pathogenesis of visceral leishmaniasis (VL) was examined by studying spontaneous and Leishmania antigen (LAg)-induced apoptosis using cryopreserved peripheral blood mononuclear cells (PBMC) of Sicilian patients with VL. Results indicate that monocytes and T lymphocytes from acute VL patients show a significantly higher level of apoptosis compared with that observed in healed subjects. The percentage of apoptotic cells was higher in monocytes than in T lymphocytes. T cells involved in programmed cell death (PCD) were mainly of the CD4(+) phenotype. In particular, the T helper 1-type (Th1) subset, as evaluated by chemokine receptor-5 (CCR5) expres…
Granulocyte and natural killer activity in the elderly
The deterioration of the immune system in ageing, 'immunosenescence', is thought to contribute to increased morbidity and mortality from infections and possibly autoimmune diseases and cancer. The most profound changes involve effector and immunoregulatory T-cell functions. Immunosenescence appears also to be related to changes in non specific immunity as well. In the present study we have assessed superoxide production, chemotaxis and the expression of the apoptosis-related molecule APO1/Fas (CD95) on neutrophils (PMN) from young and old subjects. Furthermore, we have measured the basal natural killer (NK) activity of young and elderly subjects and we have compared the number of CD16+ cell…
HLA-B8,DR3 haplotype affects lymphocyte blood levels
The number of lymphocytes in the blood is constant, pointing to an effective control of circulating lymphocyte values. The mechanisms of this regulation are uncertain, although it is likely that the number of blood lymphocytes is conditioned by hormones, homing factors and cytokines whose production is at least partly restrained by genetic factors. Particularly genetic factors linked to major histocompatibility complex (MHC) appear to be involved. In human beings a decreased number of blood lymphocytes has been described in healthy subjects carrying the Human Leucocyte Antigens (HLA) haplotype HLA-B8,DR3. In the present study, to inquire into the mechanisms of this lymphocyte decreased numb…
Cross-talk between Vβ8+and γδ+T lymphocytes in contact sensitivity
We have previously reported that T lymphocytes proliferating in vitro to the hapten trinitrochlorobenzene (TNCB) exhibit a very restricted V beta gene usage and response to TNCB is limited to T-cell receptors (TCR) composed of V beta 8.2 in combination with V alpha 3.2, V alpha 8 and V alpha 10. This paper investigates the role played by T lymphocytes expressing the V beta 8.2 gene segment in the contact sensitivity (CS) reaction to TNCB in the intact mouse and in its passive transfer into naive recipient mice. Mice injected with monoclonal antibodies to V beta 8 are unable to develop CS upon immunization with TNCB and 4-day TNCB-immune lymph node cells from mice that had been depleted in v…
Serum Levels of Soluble CD23 in Patients with Asthma or Rhinitis Monosensitive to Parietaria. Its Relation to Total Serum IgE levels and Eosinophil Cationic Protein during and out of the Pollen Season
The diagnostic value for allergies of the low affinity IgE receptor and its soluble circulating fragment (sCD23) remains unclear. In particular, little is know about seasonal influences on serum sCD23 levels in subjects with pollen allergy. In the present study, to gain insight into pathophysiological role of sCD23, we have analyzed, in blood from patients allergic to Parietaria sCD23, IgE, and eosinophil cationic protein (ECP) serum levels. IgE were assessed as atopy markers and ECP as an inflammation marker. Patients were studied during and out of pollen season, and results were compared to those obtained in nonallergic subjects. The study population included 42 nonsmoking outpatients, li…
Biological Basis of the HLA-B8,DR3-Associated Progression of Acquired Immune Deficiency Syndrome
The factors influencing the evolution of human immunodeficiency virus (HIV) infection are not fully known, but the host genotype undoubtedly plays a role in determining the outcome of the disease by affecting the immune response to HIV. The role of the host human leukocyte antigen (HLA) genotype in the regulation of susceptibility to HIV infection and expression has been studied extensively in different major risk groups. Certain HLA alleles and haplotypes, being associated with aberrant immune responses independently from HIV infection, have been reported to facilitate the rapid progression of disorders related to HIV infection. Particularly, the association of rapid acquired immunodeficie…
Interleukin-12 release by mitogen-stimulated mononuclear cells in the elderly.
Abstract Defects involving cellular expression of activation molecules, cell mediated immune response and natural killer (NK) activity are commonly observed in the elderly. Herein, data are reported on the evaluation of IL-12 production by old subjects. IL-12 is, actually, considered the key molecule for the induction of a T helper 1 (Th1) -type and NK response. IL-12 production from old subjects peripheral blood mononuclear cells (PBMNC) was evaluated using T-independent (bacterial lipopolysaccharide, LPS) or -dependent (phytoemagglutinin, PHA; immobilized anti-CD3 monoclonal antibodies, anti-CD3) mitogens. The IL-12 production after LPS stimulation was not reduced in cultures from old sub…
Early activation of γδ T lymphocytes in the elderly
T cell function is altered in vivo and in vitro in elderly compared with young subjects, and this alteration is believed to contribute to morbidity and mortality in man due to the greater incidence of infection, as well as autoimmunity and cancer in elderly. The majority of T cells express TCRalphabeta whereas TCRgammadelta is expressed on a minority of T cells. Moreover, it is known that gammadelta T lymphocytes display major histocompatibility complex (MHC)- unrestricted cytotoxicity that is reminiscent of natural killer (NK) activity. In view of earlier findings on both T cells and NK cells in the elderly, we hypothesised a different behaviour of gammadelta T lymphocytes from old subject…