Search results for "B-LYMPHOCYTE"
showing 10 items of 221 documents
Priming of cytotoxic T cell responses to exogenous hepatitis B virus core antigen is B cell dependent
2003
The hepatitis B virus (HBV) core antigen (HBcAg) has a unique ability to bind a high frequency of naive human and murine B cells. The role of HBcAg-binding naive B cells in the immunogenicity of HBcAg is not clear. The HBcAg-binding properties of naive B cells were characterized using HBcAg particles with mutated spike region (residues 76-85) sequences. Deletion of residues 76-85 (HBcDelta76-85) destroyed naive B cell binding, whereas deletion of residues 79-85 did not. HBcAg particles with an Ile instead of the natural Ala at position 80 did not bind naive B cells, whereas reversion of Ile80--Ala restored B cell binding. Destroying the B cell-binding ability of HBcAg had a marginal effect …
Hepatitis C virus antibody secretion in vitro by peripheral blood lymphocytes.
1992
A recombinant polypeptide corresponding to a virus-specific cDNA clone (c100-3) serves as the antigen for a hepatitis C virus (HCV) antibody assay. Previous investigations have shown an 80% prevalence of HCV antibodies in sera of patients suffering from post-transfusional chronic hepatitis non-A, non-B, but positive results were also obtained for 30 to 70% of sera from patients with chronic hepatitis B or autoimmune hepatitis. In this study we show that HCV antibodies are secreted by peripheral blood lymphocytes (PBL) in vitro. PBL from 12/35 patients with chronic non-A, non-B hepatitis and 1/6 patients with chronic active hepatitis B spontaneously secreted HCV antibodies in cell culture su…
In vitro production of anti-neutrophilocyte-cytoplasm-antibodies (ANCA) by Epstein-Barr virus-transformed B-cell lines in Wegener's granulomatosis.
1991
The frequent detection of anti-neutrophilocyte-cytoplasm-antibodies (ANCA) in patients with Wegener's granulomatosis (WG) led to the supposition that this disease might be of autoimmune nature. For some authors assume that Epstein-Barr virus (EBV) infection of human B-lymphocytes besides polyclonal activation could reveal the cryptic immune status against different autoantigens in patients with autoimmune diseases we investigated EBV-transformed B-lymphocytes from patients with Sjögren's syndrome, mixed connective tissue disease, WG and healthy blood donors. Two stable B-cell lines (Ho3, We1) could be established. Inhibition experiments showed that antibodies produced by transformed B-lymph…
Recombinant virus-like particles as a carrier of B- and T-cell epitopes of hepatitis C virus (HCV)
2005
The major aim of the project was the development of virus-like particles (VLP) displaying B- and T-cell epitopes of hepatitis C virus (HCV) proteins. To this end, hepatitis B virus core (HBc) particles were used as a carrier of HCV epitopes. Fragments of HCV genes encoding core (aa 98) and NS3 (aa 155) proteins were fused to the 3' terminus of the truncated HBV core gene. All recombinant plasmids led to relatively high levels of expression of chimeric proteins in E. coli, which resulted in the formation of complete "mature" VLP. Chimeric HBc/HCV VLPs were purified by combination of gel filtration and sucrose gradient centrifugation, and used for immunogenicity studies in mice. All variants …
Over 30% of patients with splenic marginal zone lymphoma express the same immunoglobulin heavy variable gene: ontogenetic implications.
2012
We performed an immunogenetic analysis of 345 IGHV-IGHD-IGHJ rearrangements from 337 cases with primary splenic small B-cell lymphomas of marginal-zone origin. Three immunoglobulin (IG) heavy variable (IGHV) genes accounted for 45.8% of the cases (IGHV1-2, 24.9%; IGHV4-34, 12.8%; IGHV3-23, 8.1%). Particularly for the IGHV1-2 gene, strong biases were evident regarding utilization of different alleles, with 79/86 rearrangements (92%) using allele *04. Among cases more stringently classified as splenic marginal-zone lymphoma (SMZL) thanks to the availability of splenic histopathological specimens, the frequency of IGHV1-2*04 peaked at 31%. The IGHV1-2*04 rearrangements carried significantly lo…
Minimal peripheral blood cells carrying clonal markers of b cell disorders: Evidence for monoclonality of circulating lymphocytes in patients with mu…
1989
Peripheral blood lymphocytes (PBL) of 20 patients with multiple myeloma (MM) were assayed for clonality by Southern blot and cell surface marker analysis. Eight samples showed monoclonal origin of circulating lymphocytes by demonstrating rearrangements of the heavy chain immunoglobulin gene (IgH). In selected experiments, comparison of IgH rearrangements of bone marrow plasma cells and peripheral blood-derived mononuclear cells, highly enriched for B lymphocytes, proved to be identical. However, monoclonal circulating cells could not be detected in samples with rearranged IgH genes by surface marker phenotyping using one-color immunofluorescence analysis and a panel of monoclonal and polycl…
Toll-like receptors – sentries in the B-cell response
2009
Summary Toll-like receptors (TLR) play a central role in the initiation of the innate immune response to pathogens. Upon recognition of molecular motifs specific for microbial molecules TLR mediate pro-inflammatory cytokine secretion and enhance antigen presentation; in B cells they further promote expansion, class switch recombination and immunoglobulin secretion. As a result of their adjuvant properties, TLR ligands have become an integral component of antimicrobial vaccines. In spite of this, little is known of the direct effects of TLR engagement on B-lymphocyte function. The scope of this review is to outline the differences in TLR expression and reactivity in murine and human B-cell s…
B cell activating factor (BAFF): Structure, functions, autoimmunity and clinical implications in Systemic Lupus Erythematosus (SLE)
2020
The B cell activating factor (BAFF), or B lymphocyte stimulator (BLyS), is a B cell survival factor which supports autoreactive B cells and prevents their deletion. BAFF expression is closely linked with autoimmunity and is enhanced by genetic alterations and viral infections. Furthermore, BAFF seems to be involved in adipogenesis, atherosclerosis, neuro-inflammatory processes and ischemia reperfusion (I/R) injury. BAFF is commonly overexpressed in Systemic Lupus Erythematosus (SLE) and strongly involved in the pathogenesis of the disease. The relationship between BAFF levels, disease activity and damage accrual in SLE is controversial, but growing evidence is emerging on its role in renal …
A20 deficiency in B cells enhances B-cell proliferation and results in the development of autoantibodies.
2011
A20/TNFAIP3 is an ubiquitin-editing enzyme, important for the regulation of the NF-κB pathway. Mutations in the TNFAIP3 gene have been linked to different human autoimmune disorders. In human B-cell lymphomas, the inactivation of A20 results in constitutive NF-κB activation. Recent studies demonstrate that in mice the germline inactivation of A20 leads to early lethality, due to inflammation in multiple organs of the body. In this report, we describe a new mouse strain allowing for the tissue-specific deletion of A20. We show that B-cell-specific deletion of A20 results in a dramatic reduction in marginal zone B cells. Furthermore, A20-deficient B cells display a hyperactive phenotype repre…
Recognition of human renal cell carcinoma and melanoma by HLA-A2-restricted cytotoxic T lymphocytes is mediated by shared peptide epitopes and up-reg…
1996
Cytotoxic T lymphocytes (CTL) have previously been isolated from peripheral blood of patients with renal cell carcinoma (RCC). The CD8-positive CTL line MZ1257-CTL-5 (CTL-5) has been shown to lyse autologous cultured RCC cells in an HLA-A2 restricted fashion. Allogeneic, HLA-A2-matched RCC and melanoma cell lines were also lysed by CTL-5, suggesting that melanoma and renal cancer share antigenic determinants. The aim of the study was to determine whether RCC and melanoma share peptide epitopes that are recognized by CTL-5 in the context of HLA-A2 molecules. Peptides were acideulated from various cell lines, separated by reversed phase high performance liquid chromatography (RP-HPLC), and as…