scholarly journals Relative contribution of T and B cells to hypermutation and selection of the antibody repertoire in germinal centers of aged mice.

1996 ◽  
Vol 183 (3) ◽  
pp. 959-970 ◽  
Author(s):  
X Yang ◽  
J Stedra ◽  
J Cerny
Keyword(s):  
T Cells ◽  
B Cells ◽  
Somatic Hypermutation ◽  
Variable Region ◽  
Germinal Centers ◽  
Antibody Repertoire ◽  
Gene Repertoire ◽  
Aged Mice ◽  
Relative Contribution ◽  
Adult Mice

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.

scholarly journals In situ studies of the primary immune response to (4-hydroxy-3-nitrophenyl)acetyl. III. The kinetics of V region mutation and selection in germinal center B cells.

1993 ◽  
Vol 178 (4) ◽  
pp. 1293-1307 ◽  
Author(s):  
J Jacob ◽  
J Przylepa ◽  
C Miller ◽  
G Kelsoe
Keyword(s):  
B Cells ◽  
Germinal Center ◽  
Somatic Hypermutation ◽  
Point Mutations ◽  
Variable Region ◽  
Germinal Centers ◽  
Primary Immune Response ◽  
Kinetics Of ◽  
Mutation And Selection ◽  
Germinal Center B Cells

In the murine spleen, germinal centers are the anatomic sites for antigen-driven hypermutation and selection of immunoglobulin (Ig) genes. To detail the kinetics of Ig mutation and selection, 178 VDJ sequences from 16 antigen-induced germinal centers were analyzed. Although germinal centers appeared by day 4, mutation was not observed in germinal center B cells until day 8 postimmunization; thereafter, point mutations favoring asymmetrical transversions accumulated until day 14. During this period, strong phenotypic selection on the mutant B lymphocytes was inferred from progressively biased distributions of mutations within the Ig variable region, the loss of crippling mutations, decreased relative clonal diversity, and increasingly restricted use of canonical gene segments. The period of most intense selection on germinal center B cell populations preceded significant levels of mutation and may represent a physiologically determined restriction on B cells permitted to enter the memory pathway. Noncanonical Ig genes recovered from germinal centers were mostly unmutated although they probably came from antigen-reactive cells. Together, these observations demonstrate that the germinal center microenvironment is rich and temporally complex but may not be constitutive for somatic hypermutation.

scholarly journals Facultative role of germinal centers and T cells in the somatic diversification of IgVH genes.

1995 ◽  
Vol 181 (4) ◽  
pp. 1319-1331 ◽  
Author(s):  
C Miller ◽  
J Stedra ◽  
G Kelsoe ◽  
J Cerny
Keyword(s):  
T Cells ◽  
B Cells ◽  
De Novo ◽  
Somatic Hypermutation ◽  
Gene Diversity ◽  
Germinal Centers ◽  
Memory B Cells ◽  
Cd4 Cells ◽  
V Gene ◽  
Somatic Diversification

The development of memory B cells takes place in germinal centers (GC) of lymphoid follicles where antigen-driven lymphocytes undergo somatic hypermutation and affinity selection, presumably under the influence of helper T cells. However, the mechanisms that drive this complex response are not well understood. We explored the relationship between GC formation and the onset of hypermutation in response to the hapten phosphorylcholine (PC) coupled to antigenic proteins in mice bearing different frequencies of CD4+ T cells. PC-reactive GC were identified by staining frozen splenic sections with peanut agglutinin (PNA) and with monoclonal Abs against AB1-2, a dominant idiotope of T15+ anti-PC antibody. The nucleotide sequences of rearranged T15 VH1 genes were determined from polymerase chain reaction amplifications of genomic DNA from microdissected GC B cells. T15+ GC became fully developed by day 6-7 after primary immunization of euthymic mice with either PC-keyhole limpet hemocyanin (KLH) or PC-chicken gamma globulin (CGG). Yet the VH1 gene segments recovered from the primary GC as late as day 10-14 had low numbers of mutations, in contrast to responses to the haptens nitrophenyl or oxazolone that sustain high levels of hypermutation after GC formation. PC-reactive B cells proliferate in histologically typical GC for considerable periods with no or little somatic hypermutation; the signals for GC formation are independent of those for the activation of hypermutation. We then examined GC 7 d after secondary immunization with PC-KLH in euthymic mice, in nu/nu mice reconstituted with limited numbers of normal CD4+ cells before priming (CD4(+)-nu/nu) and in nu/nu mice. All of these animals develop T15+ GC after antigen priming, however, the patterns of V gene mutations in the secondary GC reflected the levels of CD4+ cells present during the primary response. VDJ sequences from secondary GC of euthymic mice were heavily mutated, but most of these mutations were shared among all related (identical VDJ joints) sequences suggesting the proliferation of mutated, memory B cells, with little de novo somatic hypermutation. In contrast, the patterns of V gene diversity in secondary GC from CD4(+)-nu/nu mice suggested that there was ongoing mutation and clonal diversification during the first week after rechallenge. The secondary GC from T cell-deficient, nu/nu mice showed little evidence for mutational and/or recombinational diversity of T15+ B cells. We conclude that the participation of CD4+ helper cells is required for full activation of the mutator in GC and takes place in a dose-dependent fashion.

scholarly journals In situ studies of the primary immune response to (4-hydroxy-3-nitrophenyl)acetyl. II. A common clonal origin for periarteriolar lymphoid sheath-associated foci and germinal centers.

1992 ◽  
Vol 176 (3) ◽  
pp. 679-687 ◽  
Author(s):  
J Jacob ◽  
G Kelsoe
Keyword(s):  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Somatic Hypermutation ◽  
Variable Region ◽  
Germinal Centers ◽  
Primary Immune Response ◽  
Cell Populations ◽  
Peanut Agglutinin ◽  
Clonal Origin

In the genetically restricted response that follows immunization with (4-hydroxy-3-nitrophenyl)acetyl coupled to protein carriers, two distinct populations of B cells are observed in the spleens of C57BL/6 mice. By 48 h postimmunization, foci of antigen-binding B cells appear along the periphery of the periarteriolar lymphoid sheaths. These foci expand to contain large numbers of antibody-forming cells that neither bind the lectin, peanut agglutinin, nor mutate the rearranged immunoglobulin variable region loci. Germinal centers containing peanut agglutinin-positive B cells can be observed by 96-120 h after immunization. Although specific for the immunizing hapten, these B cells do not produce substantial amounts of antibody, but are the population that undergoes somatic hypermutation and affinity-driven selection. Both focus and germinal center populations are pauciclonal, founded, on average, by three or fewer B lymphocytes. Despite the highly specialized roles of the focus (early antibody production) and germinal center (higher affinity memory cells) B cell populations, analysis of VH to D to JH joins in neighboring foci and germinal centers demonstrate that these B cell populations have a common clonal origin.

scholarly journals WASP confers selective advantage for specific hematopoietic cell populations and serves a unique role in marginal zone B-cell homeostasis and function

Blood ◽  
2008 ◽  
Vol 112 (10) ◽  
pp. 4139-4147 ◽  
Author(s):  
Lisa S. Westerberg ◽  
Miguel A. de la Fuente ◽  
Fredrik Wermeling ◽  
Hans D. Ochs ◽  
Mikael C. I. Karlsson ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
B Cell ◽  
Marginal Zone ◽  
Hematopoietic Cells ◽  
Selective Advantage ◽  
Relative Contribution ◽  
B Cell Homeostasis ◽  
And Function

Abstract Development of hematopoietic cells depends on a dynamic actin cytoskeleton. Here we demonstrate that expression of the cytoskeletal regulator WASP, mutated in the Wiskott-Aldrich syndrome, provides selective advantage for the development of naturally occurring regulatory T cells, natural killer T cells, CD4+ and CD8+ T lymphocytes, marginal zone (MZ) B cells, MZ macrophages, and platelets. To define the relative contribution of MZ B cells and MZ macrophages for MZ development, we generated wild-type and WASP-deficient bone marrow chimeric mice, with full restoration of the MZ. However, even in the presence of MZ macrophages, only 10% of MZ B cells were of WASP-deficient origin. We show that WASP-deficient MZ B cells hyperproliferate in vivo and fail to respond to sphingosine-1-phosphate, a crucial chemoattractant for MZ B-cell positioning. Abnormalities of the MZ compartment in WASP−/− mice lead to aberrant uptake of Staphylococcus aureus and to a reduced immune response to TNP-Ficoll. Moreover, WASP-deficient mice have increased levels of “natural” IgM antibodies. Our findings reveal that WASP regulates both development and function of hematopoietic cells. We demonstrate that WASP deficiency leads to an aberrant MZ that may affect responses to blood-borne pathogens and peripheral B-cell tolerance.

scholarly journals Analysis of the human VH gene repertoire. Differential effects of selection and somatic hypermutation on human peripheral CD5(+)/IgM+ and CD5(-)/IgM+ B cells.

1997 ◽  
Vol 99 (10) ◽  
pp. 2488-2501 ◽  
Author(s):  
H P Brezinschek ◽  
S J Foster ◽  
R I Brezinschek ◽  
T Dörner ◽  
R Domiati-Saad ◽  
...  
Keyword(s):  
B Cells ◽  
Somatic Hypermutation ◽  
Gene Repertoire ◽  
Differential Effects ◽  
Vh Gene

scholarly journals Germinal centers in human lymph nodes contain reactivated memory B cells

2007 ◽  
Vol 204 (11) ◽  
pp. 2655-2665 ◽  
Author(s):  
Richard J. Bende ◽  
Febe van Maldegem ◽  
Martijn Triesscheijn ◽  
Thera A.M. Wormhoudt ◽  
Richard Guijt ◽  
...  
Keyword(s):  
B Cells ◽  
Lymph Nodes ◽  
Germinal Center ◽  
Lymphoid Tissue ◽  
Somatic Hypermutation ◽  
Germinal Centers ◽  
Memory B Cells ◽  
Cell Clones ◽  
Clonal Origin ◽  
Successive Recall

To reveal migration trails of antigen-responsive B cells in lymphoid tissue, we analyzed immunoglobulin (Ig)M-VH and IgG-VH transcripts of germinal center (GC) samples microdissected from three reactive human lymph nodes. Single B cell clones were found in multiple GCs, one clone even in as many as 19 GCs. In several GCs, IgM and IgG variants of the same clonal origin were identified. The offspring of individual hypermutated IgG memory clones were traced in multiple GCs, indicating repeated engagement of memory B cells in GC reactions. These findings imply that recurring somatic hypermutation progressively drives the Ig repertoire of memory B cells to higher affinities and infer that transforming genetic hits in non-Ig genes during lymphomagenesis do not have to arise during a single GC passage, but can be collected during successive recall responses.

scholarly journals Viral Superantigen Drives Extrafollicular and Follicular B Cell Differentiation Leading to Virus-specific Antibody Production

1997 ◽  
Vol 185 (3) ◽  
pp. 551-562 ◽  
Author(s):  
Sanjiv A. Luther ◽  
Adam Gulbranson-Judge ◽  
Hans Acha-Orbea ◽  
Ian C.M. MacLennan
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Antibody Production ◽  
Specific Antibody ◽  
Germinal Centers ◽  
B Cell Differentiation ◽  
Virus Specific Antibody ◽  
Specific Antibody Production

Mouse mammary tumor virus (MMTV[SW]) encodes a superantigen expressed by infected B cells. It evokes an antibody response specific for viral envelope protein, indicating selective activation of antigen-specific B cells. The response to MMTV(SW) in draining lymph nodes was compared with the response to haptenated chicken gamma globulin (NP-CGG) using flow cytometry and immunohistology. T cell priming occurs in both responses, with T cells proliferating in association with interdigitating dendritic cells in the T zone. T cell proliferation continues in the presence of B cells in the outer T zone, and B blasts then undergo exponential growth and differentiation into plasma cells in the medullary cords. Germinal centers develop in both responses, but those induced by MMTV(SW) appear later and are smaller. Most T cells activated in the T zone and germinal centers in the MMTV(SW) response are superantigen specific and these persist for weeks in lymph nodes draining the site MMTV(SW) injection; this contrasts with the selective loss of superantigen-specific T cells from other secondary lymphoid tissues. The results indicate that this viral superantigen, when expressed by professional antigen-presenting cells, drives extrafollicular and follicular B cell differentiation leading to virus-specific antibody production.

Introduced T cell receptor variable region gene segments recombine in pre-B cells: Evidence that B and T cells use a common recombinase

Cell ◽  
1986 ◽  
Vol 44 (2) ◽  
pp. 251-259 ◽  
Author(s):  
George D. Yancopoulos ◽  
T.Keith Blackwell ◽  
Heikyung Suh ◽  
Leroy Hood ◽  
Frederick W. Alt
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
T Cell Receptor ◽  
Variable Region ◽  
Cell Receptor ◽  
Region Gene ◽  
Variable Region Gene

scholarly journals CD40 ligand and MHC class II expression are essential for human peripheral B cell tolerance

2007 ◽  
Vol 204 (7) ◽  
pp. 1583-1593 ◽  
Author(s):  
Maxime Hervé ◽  
Isabelle Isnardi ◽  
Yen-shing Ng ◽  
James B. Bussel ◽  
Hans D. Ochs ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
B Cell ◽  
Mhc Class Ii ◽  
Somatic Hypermutation ◽  
Cd40 Ligand ◽  
Class Ii ◽  
Cell Tolerance ◽  
B Cell Tolerance ◽  
The Impact

Hyper-IgM (HIGM) syndromes are primary immunodeficiencies characterized by defects of class switch recombination and somatic hypermutation. HIGM patients who carry mutations in the CD40-ligand (CD40L) gene expressed by CD4+ T cells suffer from recurrent infections and often develop autoimmune disorders. To investigate the impact of CD40L–CD40 interactions on human B cell tolerance, we tested by ELISA the reactivity of recombinant antibodies isolated from single B cells from three CD40L-deficient patients. Antibody characteristics and reactivity from CD40L-deficient new emigrant B cells were similar to those from healthy donors, suggesting that CD40L–CD40 interactions do not regulate central B cell tolerance. In contrast, mature naive B cells from CD40L-deficient patients expressed a high proportion of autoreactive antibodies, including antinuclear antibodies. Thus, CD40L–CD40 interactions are essential for peripheral B cell tolerance. In addition, a patient with the bare lymphocyte syndrome who could not express MHC class II molecules failed to counterselect autoreactive mature naive B cells, suggesting that peripheral B cell tolerance also depends on major histocompatibility complex (MHC) class II–T cell receptor (TCR) interactions. The decreased frequency of MHC class II–restricted CD4+ regulatory T cells in CD40L-deficient patients suggests that these T cells may mediate peripheral B cell tolerance through CD40L–CD40 and MHC class II–TCR interactions.

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