scholarly journals Secondary Heavy Chain Rearrangement

2003 ◽  
Vol 197 (1) ◽  
pp. 27-39 ◽  
Author(s):  
Debora R. Sekiguchi ◽  
Robert A. Eisenberg ◽  
Martin Weigert

The chronic graft-versus-host (cGVH) reaction results in a syndrome that closely resembles systemic lupus erythematosus (SLE). It is induced in nonautoimmune mice by the transfer of alloreactive T cells. The availability of anti-DNA transgenes allows us to study the genetic origins of autoantibodies in this model. We induced cGVH in two anti-DNA H chain site-directed transgenic mouse strains. This resulted in clonal expansion and selection of specific mutations in the anti–double-stranded (ds) DNA B cell population. These data, together with a high frequency of anti-dsDNA B cell clones recovered as hybridomas, suggested that anti-dsDNAs are the product of an antigen-driven immune response. Genetic analysis associated this response with the generation of anti-dsDNA B cells through secondary rearrangements that replaced the site-directed transgene (sd-tg) with endogenous VH genes.

1989 ◽  
Vol 170 (4) ◽  
pp. 1211-1230 ◽  
Author(s):  
T Manser

Changes in the structure and function of antibodies occur during the course of an immune response due to variable (V) region gene somatic mutation and isotype switch recombination. While the end products of both these processes are now well documented, their mechanisms, timing, and regulation during clonal expansion remain unclear. Here I describe the characterization of antibodies expressed by a large number of hybridomas derived from single B cell clones at an intermediate stage of an immune response. These data provide new insights into the mechanism, relative timing, and potential of V gene mutation and isotype switching. The data suggest that somatic mutation and isotype switching are completely independent processes that may, but need not, occur simultaneously during clonal expansion. In addition, the results of this analysis demonstrate that individual B cell clones are far more efficient than previously imagined at generating and fixing particular V region somatic mutations that result in increased affinity for the eliciting epitope. Models to account for this high efficiency are discussed. Taken together with previous data, the results of this analysis also suggest that the "somatic evolution" of V region structure to a single epitope takes place in two stages; the first in which particular mutations are sustained and fixed by antigen selection in the CDR regions of the V region genes expressed in a clone over a short period of clonal expansion, and the second in which these selected CDR mutations are maintained in the growing clone, deleterious mutations are lost, and selectively neutral mutations accumulate throughout the length of V genes over long periods of clonal expansion.


1993 ◽  
Vol 177 (2) ◽  
pp. 409-418 ◽  
Author(s):  
A K Stewart ◽  
C Huang ◽  
B D Stollar ◽  
R S Schwartz

Idiotype (Id) 16/6 marks a variable (V) region structure that occurs frequently in the human immunoglobulin repertoire. The basis of the Id has been traced to a germline heavy chain gene segment, VH18/2 (VH26). To pursue the molecular basis for the frequency of Id 16/6, we have analyzed polymerase chain reaction-generated C mu, C gamma, and VH3 family V gene libraries derived from the circulating and tonsillar B cells of four normal individuals and from the B cells of two patients with active systemic lupus erythematosus (SLE). The frequency of VH18/2 in these libraries was compared with three control VH genes, VH56P1, VH21/28, and VHA57. Plaque lifts from C mu and C gamma VH cDNA libraries were screened with gene-specific oligonucleotide probes. The frequency of VH18/2 ranged from 4 to 10% of JH+ plaques (two of five times that of control VH genes). In four VH3 family-specific libraries derived from rearranged DNA, VH18/2 represented 19-33% of VH3+ plaques. Hybridizing VH18/2 plaques were 98-100% homologous to the germline VH gene; mutations when present were often in framework 3. Extensive variation was seen in the complementarity determining region 3 sequences of these rearranged V genes. The high frequency of VH18/2 expression in the B cell repertoire was confirmed by sequencing randomly picked JH+ plaques. In two patients with active SLE the frequency of use of VH18/2 was not greater than that observed in normal subjects. These results show that VH18/2 is overrepresented in the B cell repertoire of normal subjects and suggest that the immune repertoire may be dominated by relatively few V genes.


2001 ◽  
Vol 194 (7) ◽  
pp. 927-940 ◽  
Author(s):  
Andreas Bräuninger ◽  
Tilmann Spieker ◽  
Klaus Willenbrock ◽  
Philippe Gaulard ◽  
Hans-Heinrich Wacker ◽  
...  

Angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) is a peculiar T cell lymphoma, as expanding B cell clones are often present besides the malignant T cell clones. In addition, large numbers of Epstein-Barr virus (EBV)-infected B cells are frequently observed. To analyze the differentiation status and clonal composition of EBV-harboring B cells in AILD, single EBV-infected cells were micromanipulated from lymph nodes of six patients with frequent EBV+ cells and their rearranged immunoglobulin (Ig) genes analyzed. Most EBV-infected B cells carried mutated Ig genes, indicating that in AILD, EBV preferentially resides in memory and/or germinal center B cells. EBV+ B cell clones observed in all six cases ranged from small polyclonal to large monoclonal expansions and often showed ongoing somatic hypermutation while EBV− B cells showed little tendency for clonal expansion. Surprisingly, many members of expanding B cell clones had acquired destructive mutations in originally functional V gene rearrangements and showed an unfavorable high load of replacement mutations in the framework regions, indicating that they accumulated mutations over repeated rounds of mutation and division while not being selected through their antigen receptor. This sustained selection-free accumulation of somatic mutations is unique to AILD. Moreover, the survival and clonal expansion of “forbidden” (i.e., Ig-deficient) B cells has not been observed before in vivo and thus represents a novel type of viral latency in the B cell compartment. It is likely the interplay between the microenvironment in AILD lymph nodes and the viral transformation that leads to the survival and clonal expansion of Ig-less B cells.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4021-4021
Author(s):  
James Sundblom Young ◽  
Tao Wu ◽  
Yuhong Chen ◽  
Dongchang Zhao ◽  
Heather F Johnston ◽  
...  

Abstract Abstract 4021 Chronic graft-versus-host disease (cGVHD) manifests with autoimmune symptoms (i.e. increased serum levels of autoantibodies, donor T cell infiltration in skin and salivary gland tissues, and collagen deposition in skin tissues). Donor B cells have been indicated to play an important role in the pathogenesis of cGVHD in mouse models as well as in patients, but the mechanisms remain unclear. In the current studies, using a cGVHD mouse model of DBA/2 donor to MHC-matched BALB/c host, we have observed that donor B cells are activated by donor CD4+ T cells in transplants to upregulate MHC II and co-stimulatory molecules and produce IgG autoantibodies; in turn, donor B cells mediated clonal expansion of autoreactive donor-type CD4+ T cells, as judged by TCR spectratyping and in vitro T cell proliferation in response to donor- and host-type APCs. Kinetic studies showed that the presence of donor B cells in transplants was associated with persistence of GVHD target tissue damage (i.e. sclerodermatous skin) and persistence of donor CD4+ T infiltration in the tissues in which there is an expansion of Th1 and Th2 but not Th17. The presence of donor B cells in transplants also markedly augmented tissue damage in prototypical cGVHD targets such as the salivary gland. Sorted donor CD4+ T cells from primary recipients given donor B cell-containing transplants but not from the primary recipients given B cell-depleted transplants caused cGVHD-like tissue damage in the skin and salivary gland of adoptive recipients. These results indicate that donor B cells in bone marrow transplants play an important role in the generation and expansion of pathogenic CD4+ T cells that mediate chronic GVHD tissue damage. Disclosures: No relevant conflicts of interest to declare.


1983 ◽  
Vol 158 (3) ◽  
pp. 872-884 ◽  
Author(s):  
P Legrain ◽  
G Buttin

Using monoclonal antiidiotypic antibodies, we developed a sensitive binding assay that detects molecules with one or with two idiotopes of the ABPC48 idiotype. ABPC48 cross-reactive idiotypes were thus shown to be present in substantial amounts in sera of nonimmunized mice. Levan binding sites are found on these idiotypes. During the life time of the mice, the natural anti-levan titer increases while ABPC48 idiotypic expression remains constant, suggesting different controls for these two activities. On the other hand, ABPC48 cross-reactive idiotypes participate--as minor components--in the response that follows a deliberate immunization with bacterial levan. This induction process is likely to reflect the selection of idiotopes expressed by the B cell clones preactivated in sera of nonimmunized mice rather than the activation of silent clones. We suggest that a similar situation might explain the reported emergence of ABPC48 idiotypes in animals primed with antiidiotypic antibodies and subsequently stimulated with levan.


2017 ◽  
Vol 214 (11) ◽  
pp. 3435-3448 ◽  
Author(s):  
Irina Zaretsky ◽  
Ofir Atrakchi ◽  
Roei D. Mazor ◽  
Liat Stoler-Barak ◽  
Adi Biram ◽  
...  

The germinal center (GC) reaction begins with a diverse and expanded group of B cell clones bearing a wide range of antibody affinities. During GC colonization, B cells engage in long-lasting interactions with T follicular helper (Tfh) cells, a process that depends on antigen uptake and antigen presentation to the Tfh cells. How long-lasting T–B interactions and B cell clonal expansion are regulated by antigen presentation remains unclear. Here, we use in vivo B cell competition models and intravital imaging to examine the adhesive mechanisms governing B cell selection for GC colonization. We find that intercellular adhesion molecule 1 (ICAM-1) and ICAM-2 on B cells are essential for long-lasting cognate Tfh–B cell interactions and efficient selection of low-affinity B cell clones for proliferative clonal expansion. Thus, B cell ICAMs promote efficient antibody immune response by enhancement of T cell help to cognate B cells.


1994 ◽  
Vol 24 (6) ◽  
pp. 1345-1352 ◽  
Author(s):  
Alf Grandien ◽  
Rita Fucs ◽  
Alberto Nobrega ◽  
Jan Andersson ◽  
Antonio Coutinho

Blood ◽  
1999 ◽  
Vol 93 (1) ◽  
pp. 226-234 ◽  
Author(s):  
Anne Tierens ◽  
Jan Delabie ◽  
Lieve Michiels ◽  
Peter Vandenberghe ◽  
Chris De Wolf-Peeters

Abstract Splenic marginal-zone B cells, marginal-zone B cells of Peyer’s patches in the gut, and nodal marginal-zone B cells (also identified as monocytoid B cells) share a similar morphology and immunophenotype. These cells likely represent a distinct subset of B cells in humans and rodents, but their precise ontogenetic relationship as well as their origin from B cells of the germinal center is still debated. To study this, we performed a mutation analysis of the rearranged immunoglobulin variable genes (VH) of microdissected single nodal and splenic marginal-zone cells. In addition, we investigated the presence of proliferating cells and B-cell clones in the human splenic and nodal marginal zone as well as adjacent germinal centers. This was performed by immunohistochemical staining for the Ki-67 antigen and denaturing gradient gel analysis of amplified immunoglobulin heavy chain genes’ complementarity determining region 3 of microdissected cell clusters. A variable subset of nodal and splenic marginal-zone B cells showed somatic mutations in their rearranged VH genes, indicating that both virgin and memory B cells are present in the nodal and splenic marginal zone. Nodal and splenic marginal-zone B cells preferentially rearranged VH3 family genes such as DP47, DP49, DP54, and DP58. A preferential rearrangement of the same VH genes has been shown by others in the peripheral CD5− IgM+ B cells. These data suggest that the splenic and nodal marginal-zone B cells are closely related B-cell subsets. We also showed that marginal-zone B cells may cycle and that clones of B cells are frequently detected in the nodal as well as the splenic marginal zone. These clones are not related to those present in adjacent germinal centers. These data favor the hypothesis that clonal expansion occurs in the marginal zone. Whether the somatic hypermutation mechanism is activated during the clonal expansion in the marginal zone and which type of immune response triggers the clonal expansion need to be elucidated.


1999 ◽  
Vol 190 (7) ◽  
pp. 903-914 ◽  
Author(s):  
Calin Tatu ◽  
Jian Ye ◽  
Larry W. Arnold ◽  
Stephen H. Clarke

Phosphatidyl choline (PtC)-specific B cells segregate to the B-1 subset, where they comprise up to 10% of the B-1 repertoire. About half express VH12 and Vκ4/5H and are restricted in VHCDR3. We have previously reported that anti-PtC VHCDR3 is enriched among VH12-expressing cells by selective elimination of pre-B cells. We report here a bias for Vκ4/5H expression among VH12-expressing B cells, even among those that do not bind PtC and are not B-1. This is due in part to an inability of VH12 to associate with many light (L) chains but must also be due to a selective advantage in survival or clonal expansion in the periphery for Vκ4/5H-expressing cells. Thus, the bias for Vκ4/5H expression is independent of PtC binding, and, as segregation to B-1 occurs after Ig gene expression, it precedes segregation to the B-1 subset. In 6-1 mice, splenic B-1 cells reside in follicles but segregate to follicles distinct from those that contain B-2 cells. These data indicate that selection at multiple developmental checkpoints ensures the co-expression of an anti-PtC VHCDR3 and L chain in a high frequency of VH12 B cells. This focus toward specificity for PtC facilitates the development of a large anti-PtC B-1 repertoire.


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