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Ujvari B, Madsen T. Do natural antibodies compensate for humoral immunosenescence in tropical pythons? Funct Ecol 2011. [DOI: 10.1111/j.1365-2435.2011.01860.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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2
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Twohig JP, Pappworth IY, Sivasankar B, Kulik L, Bull M, Holers VM, Wang EC, Marchbank KJ. Defective B cell ontogeny and humoral immune response in mice prematurely expressing human complement receptor 2 (CR2, CD21) is similar to that seen in aging wild type mice. Mol Immunol 2009; 46:2002-13. [PMID: 19359041 PMCID: PMC2706330 DOI: 10.1016/j.molimm.2009.03.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Revised: 03/12/2009] [Accepted: 03/14/2009] [Indexed: 02/03/2023]
Abstract
Mice prematurely expressing human CR2 (hCR2) in the B cell lineage have a defective B cell ontogeny and humoral immune response. We have previously determined altered tyrosine phosphorylation patterns within hCR2 transgenic mice, suggesting that irreversible changes in B cell signaling pathways had occurred, which could explain the B cell unresponsiveness associated with hCR2 transgene expression. In support of that assertion, we found that increasing antigen dose or addition of adjuvant had a minimal impact on the ability of B cells to respond to antigen. However, analysis of aged hCR2high mice (1 year plus) revealed that both B cell numbers, B cell sub-population distribution including expansion of a newly described B regulatory cell subset, and immune responses were comparable with age-matched hCR2 negative mice. Finally, we established that B cell unresponsiveness to antigen in aging wild type mice (1 year plus) was equivalent to that noted in 3-month-old hCR2high mice. This data provides evidence that 3-month-old hCR2high mice have a humoral immune system resembling aged mice and suggests that further examination of the precise molecular and cellular parallells between aged wild type mice and 3-month-old hCR2high mice could provide an important insight into the mechanisms which lead to B cell unresponsiveness in the aging immune system.
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Affiliation(s)
- Jason P. Twohig
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, UK
| | - Isabel Y. Pappworth
- Institute of Human Genetics, Newcastle University, Center for Life, Central Parkway, Newcastle NE1 3BZ, UK
| | | | - Liudmila Kulik
- Departments of Medicine and Immunology, University of Colorado, SOM, Denver, CO, USA
| | - Melanie Bull
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, UK
| | - V. Michael Holers
- Departments of Medicine and Immunology, University of Colorado, SOM, Denver, CO, USA
| | - Eddie C.Y. Wang
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, UK
| | - Kevin J. Marchbank
- Institute of Human Genetics, Newcastle University, Center for Life, Central Parkway, Newcastle NE1 3BZ, UK
- Corresponding author. Tel.: +44 191 222 5998; fax: +44 191 222 8988.
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3
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Kumar R, Burns EA. Age-related decline in immunity: implications for vaccine responsiveness. Expert Rev Vaccines 2008; 7:467-79. [PMID: 18444893 DOI: 10.1586/14760584.7.4.467] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Aging is associated with declines in immune system function, or 'immunosenescence', leading to progressive deterioration in both innate and adaptive immunity. These changes contribute to the decreased response to vaccines seen in many older adults, and morbidity and mortality from infection. Infections (e.g., influenza, pneumonia and septicemia) appear among the top ten most-common causes of death in adults in the USA aged 55 years and older. As immunosenescence has gathered more attention in the scientific and healthcare communities, investigators have demonstrated more links between immunosenescent changes and morbidity and mortality related to infections and declining vaccine responses. This review summarizes the recent literature on age-dependent defects in adaptive and innate immunity, data linking these defects to poor vaccine response and morbidity and mortality, current recommendations for vaccinations and potential strategies to improve vaccine efficacy in older adults.
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Affiliation(s)
- Rajesh Kumar
- Medical College of Wisconsin, 5000 W National Avenue, CC-G, Milwaukee, WI 53295, USA.
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4
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Zheng B, Switzer K, Marinova E, Wansley D, Han S. Correction of age-associated deficiency in germinal center response by immunization with immune complexes. Clin Immunol 2007; 124:131-7. [PMID: 17561442 DOI: 10.1016/j.clim.2007.04.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 04/19/2007] [Accepted: 04/28/2007] [Indexed: 10/23/2022]
Abstract
In aging, both primary and secondary antibody responses are impaired. One of the most notable changes in age-associated immune deficiency is the diminished germinal center (GC) reaction. This impaired GC response reduces antibody affinity maturation, decreases memory B cell development, and prevents the establishment of long-term antibody-forming cells in the bone marrow. It is of great importance to explore novel strategy in improving GC response in the elderly. In this study, the efficacy of immunization with immune complexes in overcoming age-associated deficiency in GC response was investigated. We show that the depressed GC response in aged mice can be significantly elevated by immunization with immune complexes. Importantly, there is a significant improvement of B cell memory response and long-lived plasma cells. Our results demonstrate that immune complex immunization may represent a novel strategy to elicit functional GC response in aging, and possibly, to overcome age-related immune deficiency in general.
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Affiliation(s)
- Biao Zheng
- Department of Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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5
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Abstract
It is now becoming apparent that the immune system undergoes age-associated alterations, which accumulate to produce a progressive deterioration in the ability to respond to infections and to develop immunity after vaccination, both of which are associated with a higher mortality rate in the elderly. Immunosenescence, defined as the changes in the immune system associated with age, has been gathering interest in the scientific and health-care sectors alike. The rise in its recognition is both pertinent and timely given the increasing average age and the corresponding failure to increase healthy life expectancy. This review attempts to highlight the age-dependent defects in the innate and adaptive immune systems. While discussing the mechanisms that contribute to immunosenescence, with emphasis on the extrinsic factors, particular attention will be focused on thymic involution. Finally, we illuminate potential therapies that could be employed to help us live a longer, fuller and healthier life.
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Affiliation(s)
- Danielle Aw
- Royal Veterinary College, Host Response and Genes and Development Group, Department of Veterinary Basic Sciences, Royal College Street, London, United Kingdom
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6
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Sehl M, Sawhney R, Naeim A. Physiologic aspects of aging: impact on cancer management and decision making, part II. Cancer J 2006; 11:461-73. [PMID: 16393480 DOI: 10.1097/00130404-200511000-00005] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In this second article of our two-part review, we focus on age-associated physiologic changes involving the nervous, endocrine, hematologic, immune, and musculoskeletal systems, with close attention to the interconnected nature of these systems. There is a well-known connection between the neuroendocrine and immune systems via the hypothalamic-pituitary-adrenal axis and via interaction by means of cytokines, hormones, and neurotransmitters. These changes may lead to a loss of integration and resiliency with age, thus decreasing the ability of the elderly patient with cancer to adapt to stressful circumstances. Prominent changes include decline in memory and cognition, and increased susceptibility to peripheral neuropathy. Hematologic and immune changes like reduced bone marrow reserve and increased susceptibility to infections have far reaching implications for cancer care in the elderly. Gradual decline in hormone levels, and changes in muscle and body composition, can lead to functional decline and frailty. Use of the clinical interventions suggested in this article, along with an appreciation of the interplay of these age-related physiologic changes and their consequences, allows oncology professionals to customize therapy and minimize side effects in the geriatric oncology patient.
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Affiliation(s)
- Mary Sehl
- Division of Hematology-Oncology and Geriatrics, David Geffen School of Medicine, University of California, Los Angeles, California 90095-1687, USA
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7
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Chelvarajan RL, Collins SM, Van Willigen JM, Bondada S. The unresponsiveness of aged mice to polysaccharide antigens is a result of a defect in macrophage function. J Leukoc Biol 2005; 77:503-12. [PMID: 15629885 DOI: 10.1189/jlb.0804449] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
A reduction in macrophage (MPhi) function with aging makes mice less responsive to bacterial capsular polysaccharides, such as those present in the pneumococcal polysaccharide vaccine, a model of thymus independent (TI) antigen (Ag). Using trinitrophenol (TNP)-lipopolysaccharide (LPS) and TNP-Ficoll, two other well-studied TI Ag, we studied the mechanistic basis of reduced MPhi function in the aged. We show that aged mice are profoundly hyporesponsive to these TI Ag. As a result of a requirement for MPhi, highly purified B cells from young-adult mice do not respond to TI Ag. When purified, young B cells were immunized with TNP-Ficoll, the antibody production from those cultures reconstituted with MPhi from aged mice was significantly lower than that seen with young MPhi. Consequently, this unresponsiveness can be overcome by a mixture of interleukin (IL)-1beta and IL-6. Upon stimulation with LPS, in comparison with young MPhi, aged MPhi secreted reduced amounts of IL-6, tumor necrosis factor alpha, IL-1beta, and IL-12, cytokines necessary for B cells to respond to TI Ag. LPS also induced aged MPhi to produce an excess of IL-10. Neutralization of IL-10 enhanced the production of proinflamatory cytokines by MPhi upon LPS stimulation and also induced Ab production by aged splenocytes. Thus, the inability of aged MPhi to help the B cell response appears to be caused by an excess of IL-10. As aged MPhi have a reduced number of cells expressing Toll-like receptor 4 and CD14, the imbalance in cytokine production might be partly a result of fewer cells expressing key components of the LPS receptor complex.
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Affiliation(s)
- R Lakshman Chelvarajan
- Department of Microbiology, Immunology and Molecular Genetics, Sanders Brown Center on Aging, University of Kentucky, Lexington, KY 40536-0230, USA
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Johnson SA, Cambier JC. Ageing, autoimmunity and arthritis: senescence of the B cell compartment - implications for humoral immunity. Arthritis Res Ther 2004; 6:131-9. [PMID: 15225355 PMCID: PMC464870 DOI: 10.1186/ar1180] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Revised: 03/04/2004] [Accepted: 03/30/2004] [Indexed: 12/29/2022] Open
Abstract
Immunosenescence is associated with a decline in both T and B lymphocyte function. Although aged individuals have normal numbers of B cells in the periphery and are capable of mounting robust humoral responses, the antibodies produced are generally of lower affinity and are less protective than those produced by young animals. Here we review multiple studies that address the mechanisms that contribute to this decline. Taken together, these studies suggest that age-associated loss of the ability to generate protective humoral immunity results in part from reduced B lymphopoiesis. As the output of new, naïve B cells declines, homeostatic pressures presumably force the filling of the peripheral B cell pool by long-lived antigen-experienced cells. Because the antibody repertoire of these cells is restricted by previous antigenic experience, they make poor quality responses to new immunologic insults.
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Affiliation(s)
- Sara A Johnson
- Integrated Department of Immunology, University of Colorado Health Sciences Center and National Jewish Medical and Research Center, Denver, Colorado, USA
| | - John C Cambier
- Integrated Department of Immunology, University of Colorado Health Sciences Center and National Jewish Medical and Research Center, Denver, Colorado, USA
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9
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Abstract
The effects of aging on the immune system are widespread and extend from hematopoietic stem cells and lymphoid progenitors in the bone marrow and thymus to mature lymphocytes in secondary lymphoid organs. These changes combine to result in a diminution of immune responsiveness in the elderly. This review aims to provide an overview of age-related changes in lymphocyte development and function and discusses current controversies in the field of aging research.
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Han S, Yang K, Ozen Z, Peng W, Marinova E, Kelsoe G, Zheng B. Enhanced differentiation of splenic plasma cells but diminished long-lived high-affinity bone marrow plasma cells in aged mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:1267-73. [PMID: 12538685 DOI: 10.4049/jimmunol.170.3.1267] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In the present work, we have dissected the mechanisms responsible for the impaired humoral responses in aging. We found that there was a substantially higher level of Ab-forming cells in the spleens of aged mice than that of young controls. However, the number of high-affinity, class-switched Ab-forming cells was severely decreased in the spleen of aged mice. The accumulation of low-affinity IgM Ab-forming cells in the spleens of aged animals was not due to a deficiency in isotype switching because the number of total IgG1 splenic plasma cells was not significantly reduced. Remarkably, plasma cells of both low and high affinity were significantly diminished in the bone marrow of aged mice compared with that of young mice. The results from reconstitution experiments showed that aged bone marrow was less supportive for plasma cells derived from young splenic B cells. These findings suggest that humoral immune deficiency in aging results from at least two mechanisms: the inability to generate sufficient numbers of high-affinity Ab-forming cells, which is a result of diminished germinal center reaction, and the defective bone marrow environment that has diminished ability to support the selection and survival of long-term Ab-forming cells.
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Affiliation(s)
- Shuhua Han
- Department of Immunology, Baylor College of Medicine, Houston, TX 77030, USA
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11
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Lu YF, Cerny J. Repertoire of antibody response in bone marrow and the memory response are differentially affected in aging mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:4920-7. [PMID: 12391204 DOI: 10.4049/jimmunol.169.9.4920] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The primary burst of Ab and germinal center (GC) formation in response to T-dependent Ag is compromised in aging mice. Here we examine the effects of aging on the post-GC phase of memory B cell differentiation and the late Ab repertoire maturation in bone marrow (BM) in mice immunized with a hapten nitrophenyl coupled to chicken gamma-globulin. Specific Ab-forming cells (AFC) with mutated V(H) genes accumulated preferentially in the BM of aged mice, although the AFC numbers and average number of mutations per V(H) were lower, and the D gene usage was less restricted compared with those in the young animals. However, the repertoire of AFC after an Ag boost demonstrated the hallmarks of Ag selection, including the recurrent mutations and canonical VD rearrangements, similar to the late primary response in young animals. It is postulated that the Ab repertoire maturation in aged mice is delayed and may be notably improved by repeated immunizations.
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Affiliation(s)
- Yi-Feng Lu
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore 21201, USA
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12
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Dailey RW, Eun SY, Russell CE, Vogel LA. B cells of aged mice show decreased expansion in response to antigen, but are normal in effector function. Cell Immunol 2001; 214:99-109. [PMID: 12088409 DOI: 10.1006/cimm.2001.1894] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Increased dysfunction of the immune system with age can be attributed to developmental changes in cell types critical for proper immune responses. Previous studies have shown defects in humoral responses of aged individuals, but have not distinguished between aged T-cell/microenvironment and intrinsic B-cell defects. Here adoptive transfer of antigen-specific transgenic B cells compared early immunopoeisis from young and aged donors in a young recipient environment. B cells from aged donors demonstrated decreased antigen-induced expansion, particularly in the lymph nodes; however, they acquired a germinal center phenotype at frequencies similar to B cells from young donors. Additionally, aged B cells produced equivalent levels of antigen-specific antibody that underwent affinity maturation and isotype switching and demonstrated similar numbers of antibody-secreting cells of switched isotype. Thus, the ability of aged B cells to respond appropriately to T-dependent antigens and differentiate into high-affinity, isotype-switched, antibody-secreting cells appears to be intact.
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Affiliation(s)
- R W Dailey
- Department of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
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13
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Abstract
The immune system of aged mice produces antibodies that are characterized by low affinity, diminished protection against infections and autoreactivity. It has been shown that these antibodies may be encoded by different immunoglobulin V genes and that the mechanism of somatic hypermutation in the V genes is inefficient. Studies on scid mice reconstituted with B and T cells from donors of different ages suggested that both lymphocyte subsets may contribute to the age-related changes in antibody repertoire. With help provided by T cells from young mice, the response to a hapten, nitrophenyl(acetyl), became gradually dominated by B-cell clones that rearranged a particular germline VH gene (V186.2). However, help from the aged T cells resulted in a heterogeneous response of B cells expressing many different V segments. Analysis of discrete foci of primary antibody-forming cells suggested that the aged T-helper cells are unable to govern the normally-occurring competition between the B-cell clones that have different affinities for the hapten. It is proposed that a signaling disequilibrium from the aged T cells, which provide less efficient help in quantitative terms, supports the growth of low-affinity B cells. This process may be exacerbated due to the apparent hyperactivity of aged B cells to CD40-mediated mitogenic signal.
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Affiliation(s)
- H Song
- Department of Microbiology and Immunology, University of Maryland, Baltimore 21201, USA
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14
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Abstract
Dysfunction of the immune system in aged individuals includes at least two important factors: accumulation of immunocytes with reduced function and accumulation of lymphocyte clones with self-reactive potential. Coincidently, there is a profound reduction of the germinal center reaction in the aged. While this reduction is likely the result of age-associated impairment in lymphocyte function (e.g. diminished response to costimulus, altered lymphokine production etc.), the reduction of germinal centers may itself make an important contribution to further immunological dysfunction.
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Affiliation(s)
- B Zheng
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore 21201-1559, USA.
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Yang X, Stedra J, Cerny J. Relative contribution of T and B cells to hypermutation and selection of the antibody repertoire in germinal centers of aged mice. J Exp Med 1996; 183:959-70. [PMID: 8642299 PMCID: PMC2192365 DOI: 10.1084/jem.183.3.959] [Citation(s) in RCA: 139] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The immune system of aged individuals often produces antibodies that have lower affinity and are less protective than antibodies from young individuals. Recent studies in mice suggested that antibodies produced by old individuals may be encoded by distinct immunoglobulin (Ig) genes and that the somatic hypermutation process in these individuals is compromised. The present study employed Ighb scid mice reconstituted with normal lymphocytes from young (2-3-mo-old) and aged (20-25-mo-old) donors and immunized with a protein conjugate of the hapten (4-hydroxy-3-nitrophenyl)acetyl (NP) to determine whether the molecular changes in antibody repertoire reflect senescence in the B cells or whether they are mediated by the aging helper T lymphocytes. The NP-reactive B cells from splenic germinal centers (GC) were recovered by microdissection of frozen tissue sections and their rearranged Ig heavy chain variable region (VH) genes of the V186.2/V3 families were sequenced. It was found that the VH gene repertoire of the GC B cells was strongly influenced by the source of the CD4+ T cells. When T cells were donated by young mice, the anti-NP response in GC was dominated by the canonical V186.2 gene, even if the responder B cells came from aged donors. However, when the mice were reconstituted with T cells from aged donors, the expression of the V186.2 gene by young B cells was diminished and the response was dominated by the C1H4 gene, another member of the V186.2/V3 family. In contrast, the somatic hypermutation process in the GC B cells followed a different pattern. The mutation frequencies in the animals that were reconstituted with both B and T cells from young donors (1/50 to 1/150 bp) were comparable to the frequencies previously reported for NP-immunized intact young/adult mice. However, when either lymphocyte subset was donated by the aged mice, the mutation frequencies declined. Thus, mice reconstituted with T cells from the aged and B cells from the young had severely compromised mutational mechanism. Likewise, the recipients of aged B and young T cells had diminished mutations even though the repertoire of their anti-NP response was dominated by the canonical V186.2 gene. It appears that the change in germine-encoded repertoire and the decrease of somatic hypermutation represent distinct mechanisms of immunosenescence and that the aging of helper T cells plays a pivotal role in both of these processes.
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Affiliation(s)
- X Yang
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore 21201, USA
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Nicoletti C, Cerny J. A study of autologous anti-idiotypic antibody-forming cells in mice of different ages and genetic backgrounds. Cell Immunol 1992; 144:332-46. [PMID: 1394446 DOI: 10.1016/0008-8749(92)90249-o] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Antibody response to phosphorylcholine, an immunodominant epitope of Streptococcus pneumoniae R36a (Pn), is characterized by a public idiotype, T15, that is expressed on a large proportion of antibody molecules produced by all mouse inbred strains. The ability of the immune system to produce an autologous antibody to T15 upon immunization with Pn vaccine was investigated using a modified ELISA plaque assay for detection of single antibody-forming cells (AFC). The limit of ELISA assay for detection of specific anti-T15 AFC is approximately 300 cells/spleen. However, our studies failed to detect any autologous anti-T15 AFC in the course of the primary antibody response to Pn vaccine in young/adult (2-4 months) BALB/c and C57BL/6 mice. Aged mice (20-22 months) also failed to develop any specific auto-anti-T15 AFC upon the primary Pn immunization, despite the fact that the anti-Pn response in these animals changes both quantitatively and qualitatively. In order to generate specific anti-T15 AFC, BALB/c mice had to be immunized repeatedly with Pn vaccine (four weekly injections) or immunized directly with T15 protein in CFA. Different results were obtained with D1.LP mice that are low responders to Pn and express lower levels of T15 Id as compared to BALB/c. Young D1.LP mice produced high numbers of auto-anti-T15 AFC of both IgM and IgG isotypes following a single immunization with Pn vaccine. The kinetics of auto-anti-T15 response in D1.LP mice was similar to that of the antigen-specific response. These results demonstrate that the ability of the immune network to produce autologous antibody to a shared Id depends on the genetic makeup of the host, and that this response may be regulated by the level of Id expression.
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Affiliation(s)
- C Nicoletti
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore 21201
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Zharhary D, Klinman NR. Antigen responsiveness of the mature and generative B cell populations of aged mice. J Exp Med 1983; 157:1300-8. [PMID: 6187890 PMCID: PMC2186981 DOI: 10.1084/jem.157.4.1300] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The deficit of humoral immune responsiveness associated with aging was investigated at the level of individual antigen-specific B cells. It was found that mature dinitrophenyl (DNP)-responsive B cells isolated from the spleen of aged mice gave rise to clones of antibody-forming cells that were normal with respect to both the amount and relative affinity of anti-DNP antibody produced. However, although the proportion of immunoglobulin-bearing cells in the spleen of aged mice was normal, the proportion of cells that responded to T cell dependent DNP-specific stimulation (1.1 per 10(6) injected cells) was significantly lower than the proportion that responded when cells were obtained from the spleen of young mice (2.3 per 10(6) injected cells). To examine the origin of this diminution in antigen-responsive B cells, the responsiveness of precursor cells from the B cell generative pool isolated as the surface immunoglobulin negative (sIg-) cells within the bone marrow was evaluated. The frequency of DNP-responsive cells in both intact bone marrow cell suspensions and the sIg- subpopulation was not significantly different when such cells were isolated from aged vs. young individuals. Thus, it would appear that among the immunologic deficits associated with aging is a decrease in the proportion of antigen-responsive B cells, which is associated with maturation of B cell clones in the aged environment and occurs during the migration of cells from the bone marrow to the spleen.
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19
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20
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Merhav S, Gershon H. The mixed lymphocyte response of senescent mice: sensitivity to alloantigen and cell replication time. Cell Immunol 1977; 34:354-66. [PMID: 145322 DOI: 10.1016/0008-8749(77)90257-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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