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

The B cell-specific mb-1 gene was recently reported to encode a putative surface glycoprotein with CD3-like structural properties. Hombach et al. suggested and presented evidence to show that this mb-1 gene encodes the 34-kDa membrane glycoprotein (B34 or IgM-alpha) associated with IgMR molecule. To identify the mb-1 gene product directly in B cells, affinity-purified MB-1-specific antibody was prepared by immunization of rabbits with synthetic MB-1 oligopeptide. Immunoprecipitation in combination with two-dimensional diagonal gel electrophoresis analysis revealed that this antibody detected a B cell-specific surface glycoprotein that is very similar to the IgM-alpha (B34) protein described by Hombach et al. However, MB-1 protein exists usually as the monomeric form on the surface of B cells, in contrast to IgM-alpha, which was detected as the dimeric (IgM-alpha/IgM-alpha or IgM-alpha/Ig-beta) protein. We also found that MB-1 protein is already expressed on the sIgM- pre-B cell lymphoma, which might suggest an alternative functional role of this B cell-specific MB-1 protein in B cell differentiation. The molecular identity of MB-1 protein and IgM-alpha (B34) is discussed.
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PMID:Direct identification of the putative surface IgM receptor-associated molecule encoded by murine B cell-specific mb-1 gene. 199 47

The intracellular transport of two closely related membrane glycoproteins was studied in the murine B cell lymphoma line, AKTB-1b. Using pulse-chase radiolabeling, the kinetics of appearance of the class I histocompatibility antigens, H-2Kk and H-2Dk, at the cell surface were compared and found to be remarkably different. Newly synthesized H-2Kk is transported rapidly such that all radiolabeled molecules reach the surface within 1 h. In contrast, the H-2Dk antigen is transported slowly with a half-time of 4-5 h. The rates of surface appearance for the two antigens closely resemble the rates at which their Asn-linked oligosaccharides mature from endoglucosaminidase H (endo H)-sensitive to endo H-resistant forms, a process that occurs in the Golgi apparatus. This suggests that the rate-limiting step in the transport of H-2Dk to the cell surface occurs before the formation of endo H-resistant oligosaccharides in the Golgi apparatus. Subcellular fractionation experiments confirmed this conclusion by identifying the endoplasmic reticulum (ER) as the site where the H-2Dk antigen accumulates. The retention of this glycoprotein in the ER does not appear to be due to a lack of solubility or an inability of the H-2Dk heavy chain to associate with beta 2-microglobulin. Our data is inconsistent with a passive membrane flow mechanism for the intracellular transport of membrane glycoproteins. Rather, it suggests that one or more receptors localized to the ER membrane may mediate the selective transport of membrane glycoproteins out of the ER to the Golgi apparatus. The fact that H-2Kk and H-2Dk are highly homologous (greater than or equal to 80%) indicates that this process can be strongly influenced by limited alterations in protein structure.
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PMID:Intracellular transport of membrane glycoproteins: two closely related histocompatibility antigens differ in their rates of transit to the cell surface. 392 33

The oligosaccharide side chains of the murine invariant chain (Ii) glycoprotein associated with the Ia antigens have been characterized. Affinity chromatography using a monoclonal antibody column was employed to purify the I-Ak antigen from lysates of the AKTB-1b B cell lymphoma. The invariant chain isolated by this procedure was subsequently digested with proteases, and the resulting glycopeptides were fractionated by reverse-phase high-pressure liquid chromatography (HPLC). The invariant chain appears to contain two glycosylation sites, both of which carry high-mannose oligosaccharides, each with a restricted size distribution and an average composition of Man6GlcNAc2 as judged by gel filtration and alpha-mannosidase digestion. These data, together with the observation that the invariant chain cannot be labeled metabolically with 3H-glucosamine, 3H-fucose, or 3H-galactose, allow the conclusion that the murine invariant chain does not contain complex oligosaccharides and is not O-glycosylated during its association with the Ia antigens.
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PMID:Characterization of the oligosaccharides from the invariant chain associated with murine Ia antigens. 640 79

The H-2Kk glycoprotein has been isolated by monoclonal antibody affinity chromatography, and an analysis of the asparagine-linked oligosaccharides present at the two major glycosylation sites has been performed. Antigen obtained from the AKTB-1b B-cell lymphoma that had been labeled with [2,6-3H]mannose for 5 or 21 h or for 5 h followed by a 5-h chase was digested exhaustively with trypsin. Each glycosylation site was then isolated by reverse phase high performance liquid chromatography using a C18 column. After removal from the peptide backbone by the almond emulsin peptide: N-glycosidase, the oligosaccharides from each isolated site were analyzed by gel filtration, ion exchange chromatography, concanavalin A affinity chromatography, and glycosidase treatment to assess the contribution of sialic acid and branching patterns of the oligosaccharide backbones to the overall microheterogeneity. The glycosylation of the H-2Kk antigen derived from several different AKTB-1b tumor preparations was examined during a period covering 1 year, during which time the tumor was passaged continuously in vivo in 2-week cycles. Our results conclusively demonstrate that the pattern of oligosaccharide microheterogeneity at the two glycosylation sites of the H-2Kk antigen derived from AKTB-1b cells is stable and that each site differs as to the specific array of oligosaccharide types found on the fully processed glycoprotein. In addition, this report describes an analytical scheme employing reverse phase high performance liquid chromatography to follow oligosaccharide processing and hydrolysis of the N-glycosidic bond by the peptide: N-glycosidase.
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PMID:Stable oligosaccharide microheterogeneity at individual glycosylation sites of a murine major histocompatibility antigen derived from a B-cell lymphoma. 660 28

CD52 is a phosphatidylinositolglycan (PIG)-anchored glycoprotein (PIG-AP) expressed on normal T and B lymphocytes, monocytes, and the majority of B-cell non-Hodgkin lymphomas. We observed the emergence of CD52- T cells in 3 patients after intravenous treatment with the humanized anti-CD52 monoclonal antibody Campath-1H for refractory B-cell lymphoma and could identify the underlaying mechanism. In addition to the absence of CD52, the PIG-AP CD48 and CD59 were not detectable on the CD52- T cells in 2 patients. PIG-AP-deficient T-cell clones from both patients were established. Analysis of the mRNA of the PIG-A gene showed an abnormal size in the T-cell clones from 1 of these patients, suggesting that a mutation in the PIG-A gene was the cause of the expression defect of PIG-AP. An escape from an immune attack directed against PIG-AP+ hematopoiesis has been hypothesized as the cause of the occurrence of PIG-AP-deficient cells in paroxysmal nocturnal hemoglobinuria (PNH) and aplastic anemia. Our results support the hypothesis that an attack against the PIG-AP CD52 might lead to the expansion of a PIG-anchor-deficient cell population with the phenotypic and molecular characteristics of PNH cells.
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PMID:Emergence of CD52-, phosphatidylinositolglycan-anchor-deficient T lymphocytes after in vivo application of Campath-1H for refractory B-cell non-Hodgkin lymphoma. 763 56

We evaluated LAK cell cytotoxicity toward a sensitive B cell lymphoma and several resistant EBV-transformed cell lines in order to explore the mechanism by which some cells are preferentially recognized as targets. Cytolysis of the sensitive cells was inhibited by monoclonal antibodies against the surface proteins LFA-1 and ICAM-1; however, surface expression of ICAM-1 was similar on the resistant and sensitive cell lines. Prevention of post-translational addition of N-linked oligosaccharides by treatment of the resistant cells with tunicamycin resulted in a dramatic enhancement in LAK cell cytotoxicity which was partially inhibited by antibodies against LFA-1 and ICAM-1. Treatment of the resistant cells with the endoglycosidase N-glycanase also increased LAK cell sensitivity. Tunicamycin treatment caused a decrease in the molecular weight of ICAM-1 from approximately 95,000 to 50,000 Da. Conjugate formation between the LAK cells and the sensitive and resistant target cells was similar before and after deglycosylation. We conclude that carbohydrate modification of ICAM-1 or an alternative glycoprotein confers resistance to LAK cell cytotoxicity in some cell lines.
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PMID:The role of N-linked carbohydrate residues in lymphokine-activated killer cell-mediated cytolysis. 790 99

Gross lesions, microscopic appearance, and immunophenotyping are reported in a retrospective study of 31 cases of equine malignant lymphoma. Immunohistochemical studies were performed on archived formalin-fixed, paraffin-embedded tissues. Monoclonal antibodies to surface glycoprotein BLA.36 and intracytoplasmic domains of mb-1 and B29 were used to document the presence of B lymphocytes in the equine tumors. Polyclonal antibody to CD3 and monoclonal antibodies to T-lymphocyte markers CD3 and CD5 revealed the presence of variable numbers of T cells within the equine lymphomas. The neoplastic component of the equine lymphomas was determined through morphologic evaluation, immunophenotyping, and the use of proliferation markers Ki-67 and proliferating cell nuclear antigen. Equine malignant lymphomas were composed of a heterogeneous cell population. Most tumors contained B and T lymphocytes. Twenty-four horses had diffuse lymphomas derived from B lymphocytes. Thirteen of these lymphomas contained primarily neoplastic B lymphocytes. Eleven additional cases of diffuse large B-cell lymphoma contained from 40% to 80% nonneoplastic T lymphocytes and were classified as T-cell-rich, large B-cell lymphomas. This is the first description of T-cell-rich, B-cell lymphoma in the horse. Six tumors with a diffuse architecture were derived from T lymphocytes. Four T-cell tumors were large-cell tumors, 1 was a small-cell tumor, and in 1 tumor the size of the cells could not be determined accurately because of autolytic change in the tissues. One diffuse large-cell lymphoma did not react with either B- or T-cell markers.
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PMID:Equine malignant lymphomas: morphologic and immunohistochemical classification. 968 67

The peripheral blood cells from a patient with a B-cell lymphoma were established in long-term tissue culture. Two years after establishment of the cells in culture they were infected with herpes simplex virus type 2 and the productivity and duration of viral persistence investigated. One week after infection the lymphoblastoid cells were productively infected and have remained so for a period of over 3 years. Expression of a viral glycoprotein antigen was evaluated by using a fluorescein-labeled monoclonal anti-herpes simplex virus type 2 antibody and revealed a spectrum of staining reactions grading from a lightly stippled to very intense pattern. Polymerase chain reaction analysis of the infected cells revealed the presence of the herpes simplex virus type 2 DNA polymerase gene in the infected cells that was absent from the uninfected lymphoblastoid cells. These results taken together with the long-term growth characteristics of both the infected and uninfected lymphoblastoid cells suggest that this cell line may be a good model system for studying viral infection, viral replication, viral latency, and clinical application for the isolation of human herpes virus.
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PMID:Persistent infection of a lymphoma cell line by herpes simplex virus. 1050 3

Autoimmune phenomena in lymphoid malignancies are often observed. However, clinical manifestations such as a secondary antiphospholipid syndrome in the presence of antiphospholipid antibodies are rarely reported. Furthermore, in the few cases of lymphomas so far reported with thrombosis associated with elevated antiphospholipid antibodies, the anti-beta2-glycoprotein-I antibodies have not been studied. We report on two cases of arterial thrombosis occuring in patients with B-cell lymphoma who presented with positive anticardiolipin and anti-beta2-glycoprotein-I antibodies. Our observation suggests that patients with non-Hodgkin's lymphoma and both anticardiolipin and anti-beta2-glycoprotein-I antibodies may be, similar to lupus patients, at considerable risk towards thrombosis, especially towards arterial thrombosis.
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PMID:Arterial thrombosis associated with anticardiolipin and anti-beta2-glycoprotein-I antibodies in patients with non-Hodgkin's lymphoma: a report of two cases. 1109 66

CD40, a glycoprotein expressed on B lymphocytes plays an important role in B cell development, growth and differentiation. The ligand for the CD40 is a 39-kDa glycoprotein (CD154) expressed on the surface of activated T lymphocytes and is essential for thymus-dependent humoral immunity. The expression of CD154 is tightly regulated and its transient expression reduces the chances of potentially deleterious bystander activation of B cells. Stimulation through CD40 has been studied in vitro by using antibodies against CD40, by membranes of activated T cells or lately, by CD154 transfected cells. In this work we have evaluated the outcome of CD40-CD40 ligand interaction in vitro and in vivo by using CD154-transfected L929 cells. In vitro assays showed that CD154-L929 cells can induce on B cells: IL-4-dependent proliferation, up-regulation of CD23, CD54 and class II molecules and can also rescue WEHI-231 B cell lymphoma from anti-IgM-induced apoptosis. Interestingly, in vivo assays revealed that when CD154-L929 cells were inoculated into the spleen, mice developed a strong but transient production of anti-erythrocyte autoantibodies. Through B lymphocyte activation with CD154-transfected L929 cells both in vitro and in vivo, our data reveal that enforced and prolonged expression of CD40 ligand overcomes the tightly regulated mechanisms of B cell activation, triggering the production of autoantibodies. This system might be used to evaluate the early steps of an autoimmune response and the role of CD40-CD154 in the induction of primary responses in vivo.
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PMID:Enforced and prolonged CD40 ligand expression triggers autoantibody production in vivo. 1174 68


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