Improved B Cell Typing for HLA-DR Using Nylon Wool Column Enriched B Lymphocyte Preparations

Abstract The responsiveness and diversity of peripheral B-cell repertoire decreases with age, possibly because of B-cell clonal expansions, as suggested by the incidence of serum monoclonal immunoglobulins and of monoclonal chronic lymphocytic leukemia (CLL)–like B lymphocytes in clinically silent adults. We phenotyped peripheral blood cells from 500 healthy subjects older than 65 years with no history or suspicion of malignancies and no evidence of lymphocytosis. In 19 cases (3.8%) a κ/λ ratio of more than 3:1 or less than 1:3 was found: 9 were CD5+, CD19+, CD23+, CD20low, CD79blow, sIglow (classic CLL-like phenotype); 3 were CD5+, CD19+, CD23+, CD20high, CD79blow, sIglow (atypical CLL-like), and 7 were CD5-, CD19+, CD20high, CD23-, CD79bbright, FMC7+, sIgbright (non–CLL-like). In 2 subjects, 2 phenotypically distinct unrelated clones were concomitantly evident. No cases were CD10+. Polymerase chain reaction (PCR) analysis demonstrated a monoclonal rearrangement of IgH genes in 15 of 19 cases. No bcl-1 or bcl-2 rearrangements were detected. Using a gating strategy based on CD20/CD5/CD79 expression, 13 additional CLL-like B-cell clones were identified (cumulative frequency of classic CLL-like: 5.5%). Thus, phenotypically heterogeneous monoclonal B-lymphocyte expansions are common among healthy elderly individuals and are not limited to classic CLL-like clones but may have the phenotypic features of different chronic lymphoproliferative disorders, involving also CD5- B cells.

Download Full-text

B-lymphocyte-induced maturation protein1 up-regulates the expression of B-cell maturation antigen in mouse plasma cells

Molecular Biology Reports ◽

10.1007/s11033-010-0028-z ◽

2010 ◽

Vol 37 (8) ◽

pp. 3747-3755 ◽

Cited By ~ 8

Author(s):

Shaoli Deng ◽

Tao Yuan ◽

Xiaoxing Cheng ◽

Rui Jian ◽

Jing Jiang

Keyword(s):

B Cell ◽

B Lymphocyte ◽

Plasma Cells ◽

Cell Maturation ◽

Mouse Plasma ◽

B Cell Maturation ◽

B Cell Maturation Antigen

Download Full-text

Scope of action of the immunoglobulin mutator system

Genome ◽

10.1139/g89-022 ◽

1989 ◽

Vol 31 (1) ◽

pp. 118-121 ◽

Cited By ~ 2

Author(s):

Matthias R. Wabl ◽

Hans-Martin Jäck ◽

R. C. von Borstel ◽

Charles M. Steinberg

Keyword(s):

B Cell ◽

Mutation Rate ◽

Heavy Chain ◽

B Lymphocyte ◽

Somatic Hypermutation ◽

Spontaneous Mutation ◽

Cell Lineage ◽

Variable Region ◽

High Rate ◽

Spontaneous Mutation Rate

The authors have developed a method to measure the rate of spontaneous mutations taking place in IgH, the gene encoding the immunoglobulin heavy chain. When an amber chain-termination codon mutates to a sense codon, translation of the polypeptide chain will be completed, and mutant cells producing the heavy chain can be detected with a fluorescent labelled antibody. The protocol used is the compartmentalization test which minimizes any effect of selection. In subclones of the pre-B lymphocyte line 18–81, the spontaneous mutation rate in the part of IgH encoding the variable region is somewhat greater than 10−5 mutations per base pair per generation. This supports the hypothesis that hypermutation is not dependent on cell stimulation by an antigen. In a hybrid between a cell of this line and a myeloma (which represents the terminal stage of the B-cell lineage), the mutation rate was too low to be determined by this test, less than 10−9. When the same loss to gain procedure system was used with an opal chain-terminating codon in the part of IgH encoding the constant region (Cμ), a high rate of reversion by deletion was found. Long (more than one exon) and short (less than one exon) deletions occurred at rates of 1.7 × 10−5 and 1.4 × 10−7 per generation, respectively. It is thought that the high rate of deletion is not related to somatic hypermutation but rather to DNA rearrangement during the heavy-chain class switch, which is occurring in these pre-B cell lines. The point mutation rate was too low to be detected above the background of deletion mutants, less than 5 × 10−8. The immunoglobulin mutator system works weakly, if at all, on two other, nonimmunoglobulin, genes tested: B2m (β2 microglobulin) and the gene for ouabain resistance.Key words: pre-B lymphocyte, B lymphocyte, spontaneous mutation rate, compartmentalization test, deletion mutation, hypermutation.

Download Full-text

Role of HLA-DR antigens in antibody production: Monoclonal anti-HLA-DR antibodies differ in their ability to directly inhibit B-cell response

Cellular Immunology ◽

10.1016/0008-8749(82)90504-4 ◽

1982 ◽

Vol 71 (1) ◽

pp. 148-158 ◽

Cited By ~ 11

Author(s):

Aimé Vazquez ◽

Dominique Charron ◽

Pierre Galanaud

Keyword(s):

B Cell ◽

Antibody Production ◽

Cell Response ◽

Hla Dr ◽

B Cell Response

Download Full-text

ERP, a new member of the ets transcription factor/oncoprotein family: cloning, characterization, and differential expression during B-lymphocyte development

Molecular and Cellular Biology ◽

10.1128/mcb.14.5.3292-3309.1994 ◽

1994 ◽

Vol 14 (5) ◽

pp. 3292-3309

Author(s):

M Lopez ◽

P Oettgen ◽

Y Akbarali ◽

U Dendorfer ◽

T A Libermann

Keyword(s):

Transcription Factor ◽

Dna Binding ◽

Gene Family ◽

B Cell ◽

Binding Sites ◽

B Lymphocyte ◽

Striking Similarity ◽

Lymphocyte Development ◽

B Lymphocyte Development ◽

Ets Transcription Factor

The ets gene family encodes a group of proteins which function as transcription factors under physiological conditions and, if aberrantly expressed, can cause cellular transformation. We have recently identified two regulatory elements in the murine immunoglobulin heavy-chain (IgH) enhancer, pi and microB, which exhibit striking similarity to binding sites for ets-related proteins. To identify ets-related transcriptional regulators expressed in pre-B lymphocytes that may interact with either the pi or the microB site, we have used a PCR approach with degenerate oligonucleotides encoding conserved sequences in all members of the ets family. We have cloned the gene for a new ets-related transcription factor, ERP (ets-related protein), from the murine pre-B cell line BASC 6C2 and from mouse lung tissue. The ERP protein contains a region of high homology with the ETS DNA-binding domain common to all members of the ets transcription factor/oncoprotein family. Three additional smaller regions show homology to the ELK-1 and SAP-1 genes, a subgroup of the ets gene family that interacts with the serum response factor. Full-length ERP expresses only negligible DNA-binding activity by itself. Removal of the carboxy terminus enables ERP to interact with a variety of ets-binding sites including the E74 site, the IgH enhancer pi site, and the lck promoter ets site, suggesting a carboxy-terminal negative regulatory domain. At least three ERP-related transcripts are expressed in a variety of tissues. However, within the B-cell lineage, ERP is highly expressed primarily at early stages of B-lymphocyte development, and expression declines drastically upon B-cell maturation, correlating with the enhancer activity of the IgH pi site. These data suggest that ERP might play a role in B-cell development and in IgH gene regulation.

Download Full-text

Fetal liver pro-B and pre-B lymphocyte clones: expression of lymphoid-specific genes, surface markers, growth requirements, colonization of the bone marrow, and generation of B lymphocytes in vivo and in vitro

Molecular and Cellular Biology ◽

10.1128/mcb.12.2.518-530.1992 ◽

1992 ◽

Vol 12 (2) ◽

pp. 518-530

Author(s):

R Palacios ◽

J Samaridis

Keyword(s):

B Cell ◽

B Lymphocytes ◽

Stromal Cells ◽

B Lymphocyte ◽

Germ Line ◽

Fetal Liver ◽

Rag 1 ◽

B Cell Precursors

We describe here the development and characterization of the FLS4.1 stromal line derived from 15-day fetal liver of BALB/c embryos and defined culture conditions that efficiently support the cloning and long-term growth of nontransformed B-220+ 14-day fetal liver cells at two stages of B-cell development, namely, pro-B lymphocytes (immunoglobulin [Ig] genes in germ line configuration) and pre-B cells (JH-rearranged genes with both light-chain Ig genes in the germ line state). All B-cell precursor clones require recombinant interleukin-7 (rIL-7) and FLS4.1 stromal cells for continuous growth in culture, but pro-B lymphocyte clones can also proliferate in rIL-3. None proliferate in rIL-1, rIL-2, rIL-4, rIL-5, rIL-6, or leukemia inhibitory factor. FLS4.1 stromal cells synthesize mRNA for Steel factor but not for IL-1 to IL-7; all pro-B and pre-B clones express c-Kit, the receptor for Steel factor, and a c-Kit-specific antibody inhibits the enhanced proliferative response of fetal liver B-220+ B-cell precursors supported by FLS4.1 stromal cells and exogenous rIL-7 but does not affect that promoted by rIL-7 alone. Northern (RNA) blot analysis of the expression of the MB-1, lambda 5, Vpre-B, c mu, RAG-1, and RAG-2 genes in pro-B and pre-B clones show that transcription of the MB-1 gene precedes IgH gene rearrangement and RNA synthesis from c mu, RAG-1, RAG-2, lambda 5, and Vpre-B genes. All clones at the pre-B-cell stage synthesize mRNA for c mu, RAG-1, and RAG-2 genes; transcription of the lambda 5 and Vpre-B genes seems to start after D-to-JH rearrangement in B-cell precursors, indicating that the proteins encoded by either gene are not required for B-cell progenitors to undergo D-to-JH gene rearrangement. These findings mark transcription of the MB-1 gene as one of the earliest molecular events in commitment to develop along the B-lymphocyte pathway. Indeed, both pro-B and pre-B clones can generate in vitro and in vivo B lymphocytes but not T lymphocytes; moreover, these clones do not express the CD3-gamma T-cell-specific gene, nor do they have rearranged gamma, delta, or beta T-cell antigen receptor genes.

Download Full-text

Partial characterization of the shift from IgG to IgA synthesis in the clonal differentiation of human leukemic bone marrow-derived lymphocytes.

Journal of Experimental Medicine ◽

10.1084/jem.142.3.549 ◽

1975 ◽

Vol 142 (3) ◽

pp. 549-559 ◽

Cited By ~ 21

Author(s):

R A Rudders ◽

R Ross

Keyword(s):

B Cell ◽

B Lymphocyte ◽

Plasma Cells ◽

Lymphocytic Leukemia ◽

B Cell Differentiation ◽

Cell Staining ◽

Clonal Origin ◽

Switch Mechanism ◽

Sequential Labeling ◽

Chain Synthesis

An unusual B-cell proliferation was noted in an individual (Tun) which was characterized by the presence of two separate populations of chronic lymphocytic leukemia (CLL) cell staining on the surface and in the cytoplasm for either IgG(k) or IgA(k). Utilizing an idiotypic antiserum prepared from the associated serum monoclonal IgG(k) protein the idiotype was detected on the surface and in the cytoplasm of both the IgG- and IgA-bearing cell populations. These observations are consistent with a common clonal origin and a switch mechanism involving IgG and IgA synthesis. Sequential-labeling of Surface Ig and intracellular Ig with antisera conjugated to opposite fluorochromes documented the progressive maturation of the terminal differentiation of the IgA-bearing cell population at a level before morphologically distinct plasma cells. The distribution and pattern of surface and cytoplasmic IgG and IgA staining in individual cells suggest that the direction of switching is from IgG to IgA synthesis. The demonstration of shared idiotypic specificity between the IgG- and IgA-bearing populations is consistent with a transition in Ig heavy chain synthesis resulting from an alternation in the CH gene. It is concluded that certain CLL clones may manifest a switch from IgG to IgA synthesis at a level of B-cell differentiation which encompasses both the B lymphocyte and the Ig-synthesizing plasma cell.

Download Full-text

Targeting CD20+ B-lymphocytes in inflammatory dilated cardiomyopathy with rituximab improves clinical course: a case series

European Heart Journal - Case Reports ◽

10.1093/ehjcr/ytz131 ◽

2019 ◽

Vol 3 (3) ◽

Cited By ~ 8

Author(s):

Carsten Tschöpe ◽

Sophie Van Linthout ◽

Frank Spillmann ◽

Maximilian G Posch ◽

Petra Reinke ◽

...

Keyword(s):

Dilated Cardiomyopathy ◽

B Cell ◽

B Lymphocytes ◽

B Lymphocyte ◽

Case Series ◽

Developed Countries ◽

Cell System ◽

Limited Information ◽

Autoimmune Myocarditis ◽

Cell Surface Molecule

Abstract Background The aetiology of dilated cardiomyopathy (DCM) is highly heterogeneous including genetic and/or acquired (infective, toxic, immune, endocrine, and nutritional) factors. The major part of acquired DCM in developed countries is caused by either viral or autoimmune myocarditis. It is believed that the activation of the T-lymphocyte cell system is the major pathomechanism underlying autoimmune myocarditis and inflammatory DCM (DCMi). However, in the hearts of a subset of patients, a significant number of CD20+ B-lymphocytes can be detected too. Limited information exists on the role of B-cell-dependent mechanisms in the progression of DCMi. Particularly CD20+ B-lymphocytes, which can be targeted by anti-CD20+ B-lymphocytes antibodies or inhibitors, might contribute to the pathogenesis of myocardial damage beyond antibody production. Case summary Here, we present a case series of six patients with subacute and chronic endomyocardial biopsy-proven CD20+ B-lymphocyte-associated DCMi, where symptomatic heart failure therapy, with or without combined immunosuppressive therapy with steroid-based treatment regime, was insufficient to improve cardiac function. Five patients improved clinically several weeks after a standard infusion protocol with rituximab, a chimeric monoclonal antibody against the pan-B-cell surface molecule CD20. Discussion Our case series shows that CD20+ B-lymphocyte persistence can play a pathophysiologic role in a subset of DCMi patients and highlights the potential of targeting CD20+ B cells in patients with prominent CD20+ B-lymphocyte persistence.

Download Full-text

Ligand-independent Signaling Functions for the B Lymphocyte Antigen Receptor and Their Role in Positive Selection during B Lymphopoiesis

Journal of Experimental Medicine ◽

10.1084/jem.194.11.1583 ◽

2001 ◽

Vol 194 (11) ◽

pp. 1583-1596 ◽

Cited By ~ 112

Author(s):

Gregory Bannish ◽

Ezequiel M. Fuentes-Pananá ◽

John C. Cambier ◽

Warren S. Pear ◽

John G. Monroe

Keyword(s):

B Cells ◽

B Cell ◽

B Lymphocyte ◽

Antigen Receptor ◽

Cell Development ◽

B Cell Development ◽

B Lymphopoiesis ◽

Biologically Relevant ◽

Developmental Progression

Signal transduction through the B cell antigen receptor (BCR) is determined by a balance of positive and negative regulators. This balance is shifted by aggregation that results from binding to extracellular ligand. Aggregation of the BCR is necessary for eliciting negative selection or activation by BCR-expressing B cells. However, ligand-independent signaling through intermediate and mature forms of the BCR has been postulated to regulate B cell development and peripheral homeostasis. To address the importance of ligand-independent BCR signaling functions and their regulation during B cell development, we have designed a model that allows us to isolate the basal signaling functions of immunoglobulin (Ig)α/Igβ-containing BCR complexes from those that are dependent upon ligand-mediated aggregation. In vivo, we find that basal signaling is sufficient to facilitate pro-B → pre-B cell transition and to generate immature/mature peripheral B cells. The ability to generate basal signals and to drive developmental progression were both dependent on plasma membrane association of Igα/Igβ complexes and intact immunoregulatory tyrosine activation motifs (ITAM), thereby establishing a correlation between these processes. We believe that these studies are the first to directly demonstrate biologically relevant basal signaling through the BCR where the ability to interact with both conventional as well as nonconventional extracellular ligands is eliminated.

Download Full-text