Lineage-Specific Telomere Shortening and Unaltered Capacity for Telomerase Expression in Human T and B Lymphocytes with Age

A subset of patients with common variable immunodeficiency (CVID), group 1a of the Freiburg classification, is characterized by increased B cells expressing low levels of CD21 (CD21 low ), lymphoproliferation and autoimmunity. The CD21 low B cells have been shown to be profoundly anergic, and defects of BCR-mediated calcium signaling and of T cells have been described in CVID 1a. We found that also the classical naïve B cells from CVID 1a patients, but not from CVID non-1a patients, proliferated poorly. The B cells of CVID 1a patients had a reduced capacity to divide reminiscent of the proliferative arrest associated with replicative senescence. Thus, we investigated whether lymphocyte dysfunction in CVID 1a was related to telomere-dependent replicative senescence, and found that both the B and the T cells from CVID 1a patients had significantly shorter telomeres compared with B and T cells from CVID non-1a patients. Telomere lengths in B and T cells were significantly correlated, indicating that the rate of telomere attrition in lymphocytes is an individual characteristic of CVID patients. Our findings suggest that telomere-dependent replicative senescence contributes to the immune dysfunction of CVID 1a patients, and may provide an important clue for a better understanding of the pathogenesis of CVID.Key words: Anergy . IntroductionCommon variable immunodeficiency (CVID) is a heterogeneous disorder characterized by reduced antibody levels with low to normal numbers of circulating B cells [1]. Only a small proportion of CVID patients can be classified by the underlying genetic defect [2], and current classifications are mainly based on the B-cell phenotype [3,4]. A subset of CVID is hallmarked by the expansion of an unusual population of B cells with reduced expression of CD21 (CD21 low ); these patients are classified as CVID group 1a according to the Freiburg study [3]. Clinically, CVID 1a is characterized by a late onset, autoimmunity and benign polyclonal lymphoproliferation [3,4]. In addition, several T-cell abnormalities have been described in CVID 1a patients [5]. 854The CD21 low B cells of CVID patients express an array of inhibitory receptor and fail to proliferate in response to BCRdependent and -independent stimuli [6,7]. However, anergy is not limited to CD21 low B cells, since all mature B cells from CVID 1a patients fail to flux calcium upon BCR triggering [8]. CD21 low B cells are also increased in patients with HIV infection [9], systemic lupus erythematosus [10], or mixed cryoglobulinemia secondary to HCV infection [11,12], all conditions characterized by B-cell hyperactivation. Although the CD21 low B cells of patients with HIV infection or HCV-associated mixed cryoglobulinemia have mutated immunoglobulin genes [10][11][12], the CD21 low B cells of CVID 1a patients are unmutated and mostly autoreactive [6,7]. Similarly to those of patients with CVID, the CD21 low B cells of patients with HIV infection are profoundly anergic to B-cell stimuli [9].In this study, we observed that the B cells fr...

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“…In agreement with the previous studies [18,19], we observed that telomere length in B and T cells from healthy donors decreased Eur. J. Immunol.…”

Section: Telomeres Are Shortened In B and T Lymphocytes From Cvid 1a supporting

confidence: 93%

“…In agreement with the previous studies [18,19], we observed that telomere length in B and T cells from healthy donors decreased with age (Fig. 4A); thus, telomere lengths in CVID patients were compared with those in healthy donors of the same or older age.…”

Section: Telomeres Are Shortened In B and T Lymphocytes From Cvid 1a supporting

confidence: 92%

Telomere‐dependent replicative senescence of B and T cells from patients with type 1a common variable immunodeficiency

et al. 2011

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“…Our results are also compatible with the hypothesis that telomere erosion accompanying lymphocyte replication is at least partly responsible for the correlation observed in PBMC between decreasing telomere length and increasing donor age or years following marrow stem cell transplantation (1,5,10).…”

Section: Resultssupporting

confidence: 90%

Flow cytometric analysis of fluorescence in situ hybridization with dye dilution and DNA staining (flow‐FISH‐DDD) to determine telomere length dynamics in proliferating cells

Potter

Wener

2005

Cytometry Pt A

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Background: Telomeres shorten during DNA replication; extensive erosion of telomeres likely promotes replicative senescence and chromosomal instability. Telomere length in individual cells has been quantified by flow cytometric analysis of fluorescence in situ hybridization (flow-FISH). To determine the rate of telomere attrition (telomere erosion per cell division), we combined flow-FISH with dye dilution and DNA staining (flow-FISH-DDD) and measured telomere-specific fluorescence in proliferating cells identified by cell generation and cell cycle phase. Methods: Peripheral blood mononuclear cells (PBMC) were stained with the cell division tracking dye carboxyfluorescein diacetate succinimidyl ester (CFSE), stimulated with phytohemagglutinin (PHA), grown for 5-6 days, hybridized with a telomere sequence-specific peptide nucleic acid fluorescent probe (PNA-Cy5), counterstained with DAPI, and analyzed by flow cytometry. The cell cycle distribution and cell division generations were respectively identified by analysis of DAPI emission and deconvo-

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“…However, the molecular mechanisms underlying these processes are poorly understood. Most early studies of immunosenescence focused on T cells and described a variety of phenotypic and functional changes, including the predominance of memory cell populations (4 -7), decreased IL-2R expression (8 -10), alterations in cytokine production (6,(11)(12)(13)(14), and telomere loss (15,16). Disruption of Ag receptor signal transduction events has also been reported in T cells from aged animals; TCR-mediated proliferation, calcium mobilization, and protein kinase activation are decreased relative to T cell responses from young animals (for review see Refs.…”

mentioning

confidence: 99%

Aging-Dependent Exclusion of Antigen-Inexperienced Cells from the Peripheral B Cell Repertoire

Johnson

Rozzo

Cambier

2002

The Journal of Immunology

119

111

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Aging is accompanied by greatly reduced B cell production in the bone marrow, yet peripheral B cell numbers do not decline. We hypothesize that this may reflect filling of the peripheral pool with B cells that are long-lived as a consequence of specificity for, and chronic stimulation by, environmental Ags. To begin to explore this possibility, we analyzed the effects of aging on B cell population dynamics in the anti-H2k/b 3-83μδ Ig-transgenic mouse. We predicted that, because they presumably do not bind environmental Ags, B cells bearing the transgenic receptor may be lost in aged animals. As seen in nontransgenic animals, total splenic B cell numbers remained constant with age in the Ig-transgenic animals despite reduced B cell production. Importantly, although the few newly produced B cells in the bone marrow of aged mice are 3-83 positive, the peripheral compartment of these mice is dominated by B cells that express endogenous Ig genes rather than the transgenes. This population includes large numbers of marginal zone-like and CD21low/−CD23low/−IgMlow B cells, as well as elevated numbers of CD5+ B cells. Many of these cells express only non-B220 CD45 isoforms, suggesting that they may be memory cells. A significant proportion of aged transgenic animals produce autoantibodies that are reactive with ssDNA, dsDNA, or histones. Results support the hypothesis that, in the face of severely reduced production with age, B cells are selected based on reactivity to environmental Ags, accumulate, and display activated phenotypes. Cells bearing 3-83-transgenic receptors are excluded from this population due to their specificity. Beyond their importance in aging, these findings define a novel form of receptor revision in which B cells are selected rather than deleted based on Ag reactivity.

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Lineage-Specific Telomere Shortening and Unaltered Capacity for Telomerase Expression in Human T and B Lymphocytes with Age

Cited by 182 publications

References 45 publications

Telomere‐dependent replicative senescence of B and T cells from patients with type 1a common variable immunodeficiency

Telomere‐dependent replicative senescence of B and T cells from patients with type 1a common variable immunodeficiency

Flow cytometric analysis of fluorescence in situ hybridization with dye dilution and DNA staining (flow‐FISH‐DDD) to determine telomere length dynamics in proliferating cells

Aging-Dependent Exclusion of Antigen-Inexperienced Cells from the Peripheral B Cell Repertoire

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