Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report that a cloned population of tumor cells can rapidly produce variants that differ in their quantitative expression of surface proteins and in their rate of immunoglobulin secretion. A fresh clonal isolate of S107 myeloma cells possessing large amounts of surface IgA was continuously passaged in vitro for 2 years. During this period, fluorescence-activated cell sorter analysis indicated the development of subpopulations possessing decreased amounts of surface IgA. Cells from these variant subpopulations were isolated by first using the cell sorter to enrich for cells with decreased amounts of surface IgA and then cloning the selected population in soft agar. The 50 sublines that were isolated showed heritable differences in their levels of surface IgA and H-2 antigens and in their rates of myeloma protein secretion. Sublines having either large amounts, intermediate amounts, or absence of surface IgA also had corresponding large amounts, intermediate amounts, or absence of myeloma protein secretion. In contrast, a decrease or loss of surface Ig did not correlate with a decrease or loss of viral envelope glycoprotein gp71 and H-2 antigens. The variants did not resemble the phenotypes of less-differentiated normal lymphocyte populations of the B-cell lineage. The isolation and characterization of these variants allows us to explore the mechanisms and pathways of tumor cell differentiation as well as to study the regulation and function of cell surface proteins.
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PMID:Clonal evolution of myeloma cells leads to quantitative changes in immunoglobulin secretion and surface antigen expression. 28 78

Two immunization techniques that enable production of mouse monoclonal antibodies were evaluated in terms of small quantities of antigen. Various amounts of purified influenza A virus particles were applied either for in vitro sensitization in cultured splenocytes or for intrasplenic immunization, followed by hybridization of the immunized cells with mouse myeloma cells. Hybridomas producing specific antibodies for influenza viral proteins were detected by enzyme-linked immunosorbent assay when more than 50 micrograms of antigens was used for the in vitro immunization method, and at least 5 micrograms was necessary for a single intrasplenic immunization. On the other hand, as little as 60 ng of antigen administered in two intrasplenic injections was sufficient to produce specific hybridomas. Two out of six randomly selected monoclonal antibodies obtained using the repeated intrasplenic immunization method were IgG and the other four were IgM. Immunoprecipitation analyses revealed that the recognized antigens involved a viral inner protein (nucleocapsid protein), as well as an envelope glycoprotein (hemagglutinin). We conclude that immunization by two direct injections of antigen into the spleen is the most effective method for sensitization with nanogram quantities of insoluble antigen such as influenza viruses.
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PMID:Effective production of mouse monoclonal antibodies against influenza virus by repeated intrasplenic immunization. 323 22

Hybrid cell lines producing monoclonal antibodies against the C3H strain of mouse mammary tumor virus (C3H MMTV) were prepared by the fusion of mouse myeloma cells with the lymphocytes of BALB/c mice that were immunized with C3H MMTV. Approximately 10% of the hybrid cells initially plated after cell fusion produced immunoglobulins that reacted in antibody-binding assays with C3H MMTV; 40 of these cells were cloned, and 6 eventually yielded stable cell lines. High concentrations of monoclonal antibodies (5 to 20 mg/ml) were obtained from serum and ascites fluid of syngeneic mice inoculated with the hybrid cells. All of the monoclonal antibodies were directed against the envelope glycoprotein gp52. Three of the hybrid cell lines produced immunoglobulins of the immunoglobulin M subclass and three produced immunoglobulin G2a. The monoclonal antibodies showed limited charge heterogeneity in light and heavy chains when analyzed by high-resolution, two-dimensional gel electrophoresis. Three serologically distinct specificities were observed when these ascites fluids were tested against different strains of MMTV. The antigenic determinants detected were the following: (i) a type-specific determinant unique to the C3H strain of MMTV; (ii) class-specific determinants shared between C3H and GR MMTVs; and (iii) a group-specific determinant found on C3H, GR, RIII, and the endogenous C3H (C3Hf) MMTVs. Because monoclonal antibodies recognize single antigenic determinants, these results demonstrate for the first time that the three patterns of antigenic reactivity for MMTV are related to individual determinants on the gp52 molecule and also clearly show that one strain of MMTV can be distinguished from other strains.
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PMID:Monoclonal antibodies identify individual determinants on mouse mammary tumor virus glycoprotein gp52 with group, class, or type specificity. 615 75

We have used chicken anti-mouse immunoglobulin antiserum to precipitate molecules from mouse T-lymphoma cells that had been radioiodinated. We analysed the immunoprecipitates by two-dimensional gel electrophoresis and compared the results with immunoprecipitates generated by other antisera. We found that the molecule precipitated by chicken anti-mouse immunoglobulin from T-lymphoma cells was identical to the mouse leukemia virus envelope glycoprotein (gp 70) produced by the T-lymphoma. Mouse IgM myeloma proteins block precipitation of T-lymphoma molecules by chicken anti-mouse immunoglobulin. We conclude that mouse IgM and gp 70 share antigenic determinants. This may lead to erroneous conclusions about the presence of immunoglobulin on T-cells.
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PMID:Murine T-lymphoma 'immunoglobulin' is identical to leukemia virus gp 70. 629 Aug 78

In an attempt to develop a specific diagnostic test for avian leukosis virus (ALV) subgroup J (ALV-J) strain Hc1, four monoclonal antibodies (MAbs), JE9, G2, 145, and J47, were generated that are specific for ALV-J envelope glycoprotein, gp85. Polymerase chain reaction (PCR) was used to amplify genomic pro-viral DNA of Avian Disease and Oncology Laboratory (ADOL)-Hc1 and ADOL-4817 envelope genes. Both open reading frames encoding glycoproteins gp85 and gp37 were cloned into baculoviruses. Abundant expression of gp85 and gp37 was detected in the recombinant viruses with specific antibody to Hc1 strain of the ALV-J. The expressed proteins were used for immunization of mice to produce hybridoma cell lines secreting MAbs specific to ALV-J envelope protein. A panel of MAbs was generated by fusing NS1 myeloma cells and spleen cells from mice immunized with the recombinant baculoviruses. With the use of an immunofluorescence assay, three MAbs (JE9, G2, 145) reacted with ALV-J but not with subgroups A, B, C, D, or E of ALV. MAb J47 reacted with all exogenous subgroups of ALV including A, B, C, D, and J but not with endogenous subgroup E viruses. Western blot analysis was performed with all four MAbs against recombinant baculovirus and Hc1-infected chicken embryo fibroblast (CEF) lysates. A major band with a molecular weight about 90 kD corresponding to the size of ALV-J envelope was consistently obtained. With these MAbs, we detected the Hc1 antigen in CEFs infected with several ALV-J viruses isolated in the United States and also in tissue sections from chickens infected with Hc1 strain of ALV-J. These MAbs will be useful reagents for the diagnosis of ALV-J infection because they recognize a common antigenic epitope in six isolates tested thus far.
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PMID:Development and characterization of monoclonal antibodies to subgroup J avian leukosis virus. 1178 97

Live attenuated measles virus (MV-Edm) has potent oncolytic activity against myeloma xenografts in mice. Therapy of multiple myeloma, a disseminated plasma cell malignancy, would require systemic administration of the virus. Thus, the virus should ideally be targeted to infect only myeloma cells to minimize collateral damage to normal tissues: viral binding to its natural receptors must be ablated and a new specificity domain that targets entry into myeloma cells be added. This study covers 2 critical steps toward generating such a retargeted virus: (1) a new specificity domain against the plasma cell marker CD38 was constructed in the form of a single-chain antibody (scFv) and (2) display of that scFv on the measles viral envelope glycoprotein successfully redirected virus entry through CD38 expressed on target cells devoid of the natural MV receptors. The anti-CD38 scFv was tethered to the C-terminus of the hemagglutinin (H) glycoprotein of MV-Edm through a Factor Xa protease cleavable linker. Immunoblot analysis demonstrated that the scFv was efficiently incorporated into recombinant viral particles. Replication of MV-alpha CD38 was not hindered by the scFv, reaching titers comparable to MV-Edm. Chinese hamster ovary (CHO) cells were resistant to infection by MV-Edm and MV-alpha CD38. In contrast, CHO cells expressing CD38 became susceptible to infection by MV-alpha CD38 but not MV-Edm. Removal of the displayed scFv rendered MV-alpha CD38 noninfectious on CHO-CD38 cells. Tumorigenicity of CHO-CD38 cells in immunocompromised mice was significantly attenuated by MV-alpha CD38, resulting in enhanced survival of these mice compared with the control group.
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PMID:Oncolytic measles viruses displaying a single-chain antibody against CD38, a myeloma cell marker. 1243 86

AMD3100 was found to inhibit HIV-1 and HIV-2 within the 1-10nM concentration range while not being toxic to the host cells at concentrations up to 500 microM, thus achieving a selectivity index of approximately 100,000. The target of action was initially thought to be the viral envelope glycoprotein gp120. It appeared only to be the indirect target. The direct target of action turned out to be the co-receptor CXCR4 used by T-lymphotropic HIV strains (now referred to as X4 strains) to enter the cells. Initial (phase I) clinical trials undertaken with AMD3100, as a prelude to its development as a candidate anti-HIV drug for the treatment of AIDS, showed an unexpected side effect: an increase in the white blood cell counts. Apparently, AMD3100 specifically increased CD34+ hematopoietic stem cell counts in the peripheral blood. Stromal derived factor 1 (SDF-1), through its interaction with CXCR4, retains the stem cells in the bone marrow (a process referred to as "homing"), and AMD3100 specifically antagonizes this interaction. AMD3100 in combination with granulocyte colony-stimulating factor (G-CSF) resulted in the collection of more progenitor cells than G-CSF alone. At present, the major indication for clinical use of AMD3100 (Mozobil) is the mobilization of hematopoietic stem cells from the bone marrow into the circulating blood for transplantation in patients with hematological malignancies such as non-Hodgkin's lymphoma or multiple myeloma.
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PMID:The AMD3100 story: the path to the discovery of a stem cell mobilizer (Mozobil). 1916 86

A lot of genes deregulated in malignant plasma cells (PCs) involved in multiple myeloma have been reported these last years. The expression of some of these genes is associated with poor survival. A critical step is to elucidate the biological mechanisms triggered by these gene products. Such studies are hampered by the difficulty to obtain malignant PCs and to genetically modify them. Usual lentiviral vectors (LVs) pseudotyped with vesicular stomatitis virus envelope glycoprotein poorly transduced healthy and malignant PCs. Here, we report that LVs pseudotyped with the hemagglutinin and fusion glycoproteins from the measles Edmonston strain (H/F-LVs) can efficiently and stably transduce healthy and primary malignant PCs, without modifying their main phenotypic characteristics. Both LV pseudotypes efficiently transduced human myeloma cell lines. Importantly, both healthy and malignant PCs expressed CD46 and SLAMF1/CD150 membrane proteins, which are critical receptors for binding and productive genetic modification by H/F-LVs. The ability to efficiently introduce and express a given gene into PCs opens the possibility to study in detail PC biology.
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PMID:Efficient transduction of healthy and malignant plasma cells by lentiviral vectors pseudotyped with measles virus glycoproteins. 2231 50