Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0079731 (B-cell lymphoma)
 16,671 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epstein-Barr virus (EBV) is generally held to infect B cells and epithelial cells, although there are now reports of EBV infection in normal T cells and neoplastic T-cell diseases. In patients with human immunodeficiency virus (HIV) infection, EBV is associated with the benign epithelial lesion, hairy leukoplakia, and has been reported in up to 80% of acquired immunodeficiency syndrome (AIDS)-related B-cell lymphoma. This study shows the presence of EBV in malignant oral T-cell lymphoma in three AIDS patients, two of whom had concurrent manifestation of hairy leukoplakia. The T-cell lineage of the tumor cells was determined by positive immunophenotyping for T-cell markers and lack of B-cell or nonhematopoietic (cytokeratin) determinants. All tumors contained monoclonal T-cell populations shown by polymerase chain reaction, which showed amplification of T-cell receptor gamma chain DNA without evidence of Ig heavy chain gene rearrangement. Furthermore, these lesions showed the presence of EBV DNA and expression of EBV latent gene products in the tumor cells. EBV involvement in AIDS-related T-cell lymphoma has not been widely reported and may represent a further manifestation of opportunistic EBV infection arising in the HIV-immunocompromised host.
 ...
PMID:Epstein-Barr virus-related oral T-cell lymphoma associated with human immunodeficiency virus immunosuppression. 838 15

The value of gene analysis was assessed in patients with pulmonary pseudolymphoma. Two patients with histopathologic evidence of pseudolymphoma took part in the study. High molecular weight DNA was extracted from resected specimens and digested with restriction enzymes, followed by southern blotting. Gene rearrangement of immunoglobulins and T-cell receptors was investigated using DNA probes against heavy chain (H chain), kappa chain, and lambda chain of immunoglobulin genes and that against the beta-chain of T-cell receptor genes. Both patients with pseudolymphoma showed rearranged bands for the H chain; B-cell lymphoma was diagnosed from the gene analysis. Gene analysis is a valuable method when it is difficult to judge whether the tumor cells are of T-cell origin or B-cell origin in phenotype analysis by immunohistologic studies and when it should be judged whether or not the lymphoid hyperplasia is tumor related.
 ...
PMID:Gene analysis of pulmonary pseudolymphoma. 843 14

A conditional mutant of Epstein-Barr virus nuclear antigen 2 (EBNA2) regulated by estrogen was employed to study the effect of EBNA2 on the cellular phenotype. Activation of EBNA2 in lymphoblastoid cell lines (LCLs) and in B cell lymphoma lines resulted in down-regulation of cell surface IgM and Ig-mu steady-state RNA expression. In LCLs, activation of EBNA2 is required for maintaining proliferation, whereas in Burkitt's lymphoma (BL) cell lines with t(8;14) translocations, activation of EBNA2 induces growth arrest. In these cells, Northern and nuclear run-on analyses revealed rapid simultaneous repression of Ig-mu and c-myc transcription as early as 30 min after activation of EBNA2. Since c-myc expression is under the control of the Ig heavy chain locus in BL cell lines with a t(8;14) translocation, we propose that Ig-mu and c-myc are down-regulated by EBNA2 through a common mechanism.
 ...
PMID:Epstein-Barr virus nuclear antigen 2 is a transcriptional suppressor of the immunoglobulin mu gene: implications for the expression of the translocated c-myc gene in Burkitt's lymphoma cells. 861 12

A monoclonal antibody (mAb), designated SCH94.03, which promotes central nervous system remyelination in susceptible mice infected with Theiler's virus, has been proposed to be a natural autoantibody based on its germline immunoglobulin sequence. To identify the potential antigens recognized by mAb SCH94.03, a rat brain lambda gtll cDNA expression library was screened with this antibody. Nine independent clones were identified. Five clones were identical or highly similar to known cDNAs or proteins (rat kinesin light chain, mouse thrombospondin 1, mouse oncofetal antigen, RNA polymerase beta subunit and nuclear phosphoprotein). Four clones, designated REM#1, REM#2, REM#3 and REM#4, contained open reading frames, but were not homologous to any known genes or proteins. The reactivity of SCH94.03 with all nine clones was specific in that all nine clones identified contained continuous open reading frames and none of nine control IgM mAbs showed reactivity with any of the nine cDNA clones. The precise specificity of binding of mAb SCH94.03 was demonstrated by the absence of reactivity to the identified clones with IgM Ab from B cell lymphoma (CH12) which has identical cDNA sequences with mAb SCH94.03, but differ only in the heavy chain CDR3 N region. Our studies support the hypothesis that highly polyreactive natural autoantibodies can play a role in promoting central nervous system remyelination.
 ...
PMID:A monoclonal autoantibody which promotes central nervous system remyelination is highly polyreactive to multiple known and novel antigens. 864 59

The murine monoclonal antibody, LL2, is a B-cell (CD22)-specific IgG2a which has been demonstrated to be clinically significant in the radioimmunodetection of non-Hodgkin's B-cell lymphoma. The antibody carries a variable region-appended glycosylation site in the light chain and is rapidly internalized upon binding to Raji target cells. Humanization of LL2 was carried out in order to develop LL2 as a diagnostic and immunotherapeutic suitable for repeated administration. Based on the extent of sequence homology, and with the aid of computer modeling, we selected the EU framework regions (FR) 1, 2 and 3, and the NEWM FR4 as the scaffold for grafting the heavy chain complementarity determining regions (CDRs), and REI FRs for that of light chains. The light chain glycosylation site, however, was not included. Construction of the CDR-grafted variable regions was accomplished by a rapid and simplified method that involved long DNA oligonucleotide synthesis and the polymerase chain reaction (PCR). The humanized LL2 (hLL2), lacking light chain variable region glycosylation, exhibited immunoreactivities that were comparable to that of chimeric LL2 (cLL2), which was shown previously to have antigen-binding properties similar to its murine counterpart, suggesting that the VK-appended oligosaccharides found in mLL2 are not necessary for antigen binding. Moreover, the hLL2 retained its ability to be internalized into Raji cells at a rate similar to its murine and chimeric counterparts.
 ...
PMID:Construction and characterization of a humanized, internalizing, B-cell (CD22)-specific, leukemia/lymphoma antibody, LL2. 864 11

The Epstein-Barr virus (EBV) nuclear antigen-1 (EBNA-1) is a pleiotropic protein which has been characterized extensively both biochemically and functionally. It is the only one of the identified latent protein-encoding genes to be consistently expressed in viral-associated endemic Burkitt's lymphoma cells. As such, it is the only candidate viral protein to possibly perform a maintenance function in the tumour pathology. Despite this, no oncogenic activity has been attributed to the protein in tissue culture assays. The experiments described here were initiated to explore the activity of the protein in B cells in vivo. EBNA-1 transgenic mice were generated with transgene expression directed to the B cell compartment using the mouse Ig heavy chain intron enhancer. Transgene expression was demonstrated in the lymphoid tissues of mice of two independent lines. Transgenic positive mice of both lines succumb to B cell lymphoma. The B cell tumours are monoclonal, frequently of follicular centre cell origin and remarkably similar to those induced by transgenic c-myc expression. These results demonstrate that EBNA-1 is oncogenic in vivo and suggest that the gene product may play a direct role in the pathogenesis of Burkitt's lymphoma and possibly other EBV-associated malignancies.
 ...
PMID:Expression of Epstein-Barr virus nuclear antigen-1 induces B cell neoplasia in transgenic mice. 867 Aug 12

The recent finding of somatically mutated mu heavy chain transcripts in human peripheral blood (PB) B lymphocytes suggests that T-dependent B-cell memory might not be restricted to class-switched cells. We provide here evidence that IgM-only PB B cells are likely to be the IgM-expressing counterpart of classical (IgM- IgD-) memory B cells in humans. As shown by molecular single cell analysis, most IgM-only cells carry mutated V region genes, like class-switched cells. Although both subsets represent populations of nonactivated, resting cells, they express higher levels of Ig mRNA than naive (IgM+ IgD+) B cells. IgM-only and class-switched cells are CD38- CD77-, and mostly CD23-, thus neither resembling germinal center nor naive B cells. Because many IgM-expressing B cells located in secondary lymphoid tissues resemble IgM-only PB B cells in terms of cell phenotype, we propose that the human lymphoid system contains a large compartment of IgM-expressing memory cells. Moreover, these cells seem to represent the nonmalignant counterparts of IgM-expressing tumor cells in sporadic Burkitt's lymphoma, MALT lymphoma, monocytoid B-cell lymphoma, and diffuse large-cell lymphoma that were found to harbor somatically mutated V genes.
 ...
PMID:Evidence for a large compartment of IgM-expressing memory B cells in humans. 902 52

Posttransplantation lymphoproliferative disorders (PT-LPDs) occurring in T-cell depleted (TCD) allogeneic bone marrow transplant recipients seem to be different from those that arise in solid organ recipients in their early development, the high incidence of extensive dissemination at presentation, and their aggressive course and high fatality rate. We report a series of 10 patients with PT-LPDs after TCD allogeneic bone marrow transplant. We studied the correlation between the morphology of the lesions; their clonality based on immunoglobulin (Ig) heavy chain gene rearrangement analysis and immunohistochemistry; their proliferative activity as measured by immunoperoxidase staining for the proliferating cell nuclear antigen (PCNA) and the presence of p53 gene product overexpression. Histologically, our cases corresponded to the two morphologic categories of polymorphic B-cell lymphoma (PBCL, seven cases) and malignant lymphoma immunoblastic (ML-IB, three cases). Ig light-chain staining showed monoclonality in a minority of the cases, whereas Ig gene rearrangement analysis by polymerase chain reaction revealed B-cell clonality in three of seven cases of PBCL and in all three cases of ML-IB. The Epstein-Barr virus (EBV) genome, the expression of EBV latent membrane protein or both were found in all 10 specimens. High proliferative activity (PCNA > or = 66%) was found in all cases, with a mean PCNA value of 56% in PBCL and 84% in ML-IB. Five specimens were p53+ (two of seven PBCL and three of three ML-IB). Two of four PBCL cases resolved with the administration of donor leukocytes. All of the remaining patients died of the PT-LPD within a short time from admission. Our results show that the PT-LPDs after TCD bone marrow transplantation are characterized by a high frequency of high-grade histologic subtypes, frequent monoclonality, high proliferative activity, frequent overexpression of p53 gene product, and poor prognosis. These characteristics observed in only a minority of cases of PT-LPDs occurring after solid organ transplantation may account for the less aggressive clinical behavior observed in those diseases.
 ...
PMID:Posttransplantation lymphoproliferative disorders in bone marrow transplant recipients are aggressive diseases with a high incidence of adverse histologic and immunobiologic features. 912 10

By means of the clonotypic variable region, the immunoglobulin (Ig) is a tumor-specific antigen on B cell neoplasms. We report that engagement of the B cell antigen receptor (BcR) promotes presentation of peptides derived from the B cell's intrinsic Ig to major histocompatibility complex (MHC) class II-restricted T cells. Thus, anti-Ig endowed normal, ex vivo B lymphocytes from H-2d, Ig constant heavy chain allotype b (IgCHb) mice with the capacity to stimulate an I-Ad-restricted T cell clone which recognizes the gamma 2ab 435-451 allopeptide. The corresponding self gamma 2aa peptide is cryptic and 6000-fold less antigenic than the gamma 2ab allopeptide. Even so, the syngeneic B cell lymphoma A20 which expresses surface(s) IgG2aa, was also recognized by the T cells after BcR ligation. Thus, anti-Ig triggered the disclosure of a cryptic tumor antigen determinant. We propose that autoantigens, by engaging the BcR of self-reactive B cells, induce presentation of intrinsic Ig peptides to which the T helper cell (Th) repertoire is not tolerant. In this way, B cells with anti-self potential may be activated without Th recognition of nominal autoantigen.
 ...
PMID:Engagement of the B lymphocyte antigen receptor induces presentation of intrinsic immunoglobulin peptides on major histocompatibility complex class II molecules. 917 1

The development of rapid polymerase chain reaction (PCR) protocols for amplification of rearranged heavy chain immunoglobulin (IgH) gene sequences has facilitated the identification of clonal IgH rearrangements in non-Hodgkin's lymphomas (NHL) and leukemias of B lineage. In the present report we have explored the recently described improved strategy for assessment of clonality of rearranged immunoglobulin heavy chain (IgH) genes in more detail in a series of 101 B cell malignancies and 50 polyclonal controls. The assay is based on an IgH-PCR with an automated fluorescence-based strategy for PCR detection of IgH gene rearrangements. Third complementarity determining region (IgH-CDR3) sequences were amplified using fluorescent dye labeled consensus primers homologous to the corresponding variable (V[H]) and joining (J[H]) gene segments in combination with a thermostable proofreading DNA polymerase. PCR products were size separated on a high resolution polyacrylamide gel and analyzed for clonality by exact size determination and fluorescence quantification in an automated DNA sequencer. PCR findings obtained with the optimized IgH-CDR3-PCR assay showed an overall monoclonality detection rate of 97% (97 of 101 cases with B cell neoplasms). The specificity was 100% as determined by analysis of 50 controls, all of which gave polyclonal PCR results. We found a high rate of monoclonal IgH-CDR3-PCR results not only in the leukemias and diffuse lymphoma but also in the group of follicular lymphoma, where a high rate of false negative results is frequently reported in the literature. In summary, we identified monoclonal IgH-CDR3 junctions in 55 out of 59 cases (93%) with B cell lymphoma and in 42 of 42 (100%) cases with leukemia, immunocytoma and multiple myeloma. The results demonstrate that automated fluorescence detection of IgH-CDR3-PCR products is an ideal tool for detection of clonal and polyclonal lymphoid B cells. In combination with allele-specific primers the procedure may improve current experimental approaches to detect occult malginant B cells during initial staging and follow-up of NHL and ALL patients.
 ...
PMID:Automated high resolution PCR fragment analysis for identification of clonally rearranged immunoglobulin heavy chain genes. 920 91


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>