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)

Two monoclonal Beta-cell surface antibodies M10H6 und K14D10 were obtained by fusion of spleen cells of Balb/c mice with the myeloma cell line P(3)0. The monoclonal antibody M10H6 was induced by immunization with rat insulinoma cells finally boostered with disintegrated rat islets, whereas the K14D10 was generated after immunization with porcine proinsulin. Both monoclonals belong to the IgG2A isotype and were screened with insulin-producing rat insulinoma cells by an indirect immunofluorescence test as well as by a cellular enzyme linked immunosorbent assay. In addition to the cell surface binding on living Beta cells the monoclonals react with islets on cryostat sections of rat pancreas. The anti-islet cytotoxic potential of these monoclonals was measured by 51Chromium-release in the presence of complement or Fc-receptor bearing leucocytes using 51Chromium-labelled rat islet cells as target. Both antibody secreting hybridomas were propagated in syngeneic mice resulting in high levels of islet cell surface antibodies in ascites and sera from the recipient. High anti-islet cytotoxicity was mediated by ascites fluid, but no mouse developed hyperglycaemia. Furthermore, the repeated injections of the monoclonals into rats did not exert a diabetogenic action and failed to reduce the pancreatic insulin content although the attraction of the K14D10 to the pancreatic islets in vivo could be demonstrated. We conclude that islet cell surface antibody-mediated Beta-cell lysis in vitro may not be relevant to Beta-cell destruction in vivo.
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PMID:Monoclonal antibody-mediated cytotoxicity against rat beta cells detected in vitro does not cause beta-cell destruction in vivo. 164 38

Two commonly used methods for screening hybridoma supernatants secreting monoclonal islet cell reactive antibodies (mc-ICRA) were performed to investigate the specificity of the monoclonals established. For this, endothelial, neuroblastoma, murine subcutis and two myeloma cell lines were used as targets in comparison to the insulin-producing rat insulinoma cell line (RIN), either immobilized and permeabilized in cellular enzyme linked immunosorbent assay (CELISA) or in suspension of viable cells in the indirect immunofluorescence test. In addition, rat splenocytes were used for estimating multireactivity of mc-ICRA in ELISA. Using permeabilized target cells, we obtained a high multireactivity of the monoclonal antibodies (mab) tested, indicating a high incidence of molecular mimicry between cytoplasmic antigens of different cell lines. In contrast to CELISA, if only cell surface antigens of viable cells are accessible, detected by the immunofluorescence technique, the high multireactivity is not observed. For investigating the specificity of monoclonals, the complexity of target antigens used must be taken into consideration.
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PMID:Different multiple reactivity of monoclonal islet cell binding antibodies using indirect immunofluorescence technique on viable cells or cellular ELISA on desiccated cells as target. 184 Oct 31

The BB rat provides an excellent animal model for type 1 (insulin-dependent) diabetes mellitus. Cytotoxic autoantibodies against pancreatic beta cells have been found in the sera of both patients with type 1 (insulin-dependent) diabetes and BB rats. These antibodies have been implicated in the pathogenesis of the disease. In this study, a monoclonal autoantibody, designated KT1, has been developed by the fusion of spleen cells from a BB rat and a mouse myeloma cell line. KT1 was found to be of the immunoglobulin M isotype and reacted specifically with islet cells. In microcytotoxicity assays KT1 was shown to mediate complement-dependent lysis of approximately 30% of a rat insulinoma cell line and 25% of rat pancreatic islet cells in culture. It did not cause lysis of the other cell lines tested. KT1 has been demonstrated, by indirect immunofluorescence, to bind specifically to a cell surface antigen on live and acetone-fixed islet cell cultures from Wistar rat neonates and to rat insulinoma cells. Western blotting experiments revealed reaction to a 68-kDa protein from rat insulinoma cell extracts. This monoclonal antibody may have clinical relevance as it exhibits properties similar to the islet cell surface antibodies present in the sera of BB rats.
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PMID:A cytotoxic monoclonal autoantibody from the BB rat which binds an islet cell surface protein. 240 25

To investigate the autoimmune pathogenesis of spontaneously occurring diabetes mellitus in BB rats, spleen cells of newly diagnosed diabetic BB rats were fused with mouse myeloma cells. Hybridoma supernatants were screened for antibodies by indirect immunofluorescence and by 51Cr-release assays using the RINm5F rat insulinoma cell line. One clone, E5C2, produced an IgM kappa antibody that was cytotoxic for RINm5F cells, but not for other rat cell lines nor for primary rat islet cells. However, treatment of primary rat islet cells with neuraminidase exposed surface antigens and rendered the cells susceptible to complement-mediated lysis by antibody E5C2. Using immunostaining of glycolipids separated by thin-layer chromatography, hapten inhibition assays with defined carbohydrates, and Western blots, the antigens recognized by E5C2 on RINm5F cells were identified as glycoproteins with molecular weights of 60,000 and 68,000. The antibody recognizes a carbohydrate antigen containing the sequence Gal beta 1-4GlcNAc-R, which on RINm5F cells is predominantly hidden by covalently bound sialic acid. These studies raise the possibility that hidden antigenic determinants on islet cells exposed by a variety of means may be the target of autoimmune attack.
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PMID:Pancreatic islet cell surface glycoproteins containing Gal beta 1-4GlcNAc-R identified by a cytotoxic monoclonal autoantibody. 243 47

Monoclonal antibody (Mab) 1.93B7 was obtained by fusion of spleen cells from a diabetic NOD mouse with P3X63Ag8.653 myeloma cells and screening for complement mediated lysis of rat insulinoma (RIN) cells. Immunofluorescence studies revealed that this Mab binds to RIN cells but not to the rat pituitary tumour line GH3. The binding of Mab 1.93B7 to RIN cells was abolished by trypsin but not by neuraminidase treatment of the cells, suggesting that the antigen recognized is a protein. Mab 1.93B7 bound to approximately 30% of mouse (BALB/c) and rat islet cells which had been subjected to trypsin digestion and incubated as a single cell suspension for 12h to allow reexpression of trypsin sensitive antigens. Since Mab 1.93B7 is potentially pathogenic, as suggested by its reactivity to primary islet cells and its complement fixing capacity, we injected it into BALB/c and NOD mice. Cytotoxic activity against RIN cells was detected in the serum of the animals injected with Mab 1.93B7, but the Mab did not exert a diabetogenic action and failed to reverse diabetes when administered at onset in NOD mice. No modification of the course of spleen cell mediated transfer of diabetes in NOD mice was observed when the Mab was administered from the time of spleen cell inoculation to the appearance of glycosuria. The implications of the lack of an effect in vivo of Mab 1.93B7 under the conditions employed are discussed.
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PMID:A cytotoxic monoclonal islet cell surface antibody from the NOD mouse. 269 57

Islet cell antibodies have been detected in more than 60% of newly diagnosed type I diabetics. Their pathogenetic role is still unclear. We have generated monoclonal antibodies (mc-ab) reactive with islet cell antigens by fusing mouse myeloma cells with spleen cells from Balb/c mice immunized with pancreatic islet cells. Hybridomas producing islet cell surface antibodies (ICSA) were detected by indirect immunofluorescence on viable cells from rat islets or rat insulinoma. Cytoplasmic islet cell antibodies (ICA) were detected by indirect immunofluorescence on Bouin-fixed sections of mouse pancreas. The ICSA- and/or ICA-producing hybridomas were cloned twice by limiting dilution. This paper describes six different mc-ab. All hybrid cell lines obtained produced IgM antibodies. Four of them mediate complement-dependent cytotoxicity to viable rat islet cells. In the present study the heterogeneity of circulating ICSA is demonstrated. Also, a monoclonal beta cell surface autoantibody K56aF3 was produced by fusion of spleen cells from a mouse treated with sub-diabetogenic doses of streptozotocin in combination with complete Freund's adjuvant. It was cytotoxic against islet cells up to a dilution of 1:1,000 and it could inhibit the insulin secretion from neonatal rat islets cultured in RPMI 1640 as stimulated by glucose or by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine common with glucose. The latter effect was reversible as indicated by the recovery of insulin secretion in a subsequent culture period without mc-ab. These results suggest that circulating ICSA in type I diabetics may alter beta cell function and thereby contribute to the pathogenesis of type I diabetes.
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PMID:Generation and partial characterization of monoclonal antibodies reactive with islet cell antigens. 331 74

Islet cell surface autoantibodies are present in the serum of the spontaneously diabetic BB rat. The availability in large quantities of such autoantibodies should help us understand their significance in vivo. Fusions between BB rat lymphocytes and rat myeloma cells were screened by cellular enzyme linked immunosorbent assay and indirect immunofluorescence on rat living cells. They resulted in a stable hybridoma, called IC2, secreting a monoclonal immunoglobulin M specific for the surface of rat islet cells. This monoclonal antibody was found to bind to the surface of 56% normal rat islet cells and 72% rat insulinoma cells. Protease treatment of rat islet cells resulted in a subsequent 72-100% binding inhibition of IC2 to the surface of these cells, suggesting that IC2 specific antigen is a protein.
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PMID:Production and characterization of a monoclonal islet cell surface autoantibody from the BB rat. 352 31

Monoclonal antibody 3A4 to islet cell surface antigen has been previously established in our laboratory, using hybridization of spleen lymphocytes from non-obese diabetic (NOD) mice transferred into immunologically incompetent recipient mice. In the present study, monoclonal islet cell surface antibody 5C12 could be newly obtained in the 10:1 ratio of NOD mice spleen cells and mouse myeloma cells (SP2/0) without any modifications. Protein A radioligand assay and indirect immunofluorescence on living cells showed that 5C12 antibody reacted to normal rat islet cells and cultured rat insulinoma cells (RIN-r), but not to cultured lymphocytes (Bri-7, IM-9) and Chang-liver cells. Analysis of 125I-labeled antibody binding revealed that unlabeled 5C12 effectively inhibited subsequent 125I-5C12 binding to RIN-r cells, whereas unlabeled 3A4 did not. The scatchard plot from these data showed the curvilinearity, and about 150,000 binding sites to antibody per RIN-r cell were counted. The treatment of RIN-r cells with papain and neuraminidase reduced the binding of 5C12 to RIN-r cells, whereas the effect of trypsin was not observed. Immunoprecipitation of 125I-labeled insulinoma cell lysates followed by SDS-PAGE and autoradiography indicated that 5C12 recognized 105K dalton cell surface protein in RIN-r cells. Immunoblotting also showed that 5C12 antibody recognized 105K dalton cell surface protein in RIN-r cells. These results demonstrated that 5C12 was an important tool for clarifying the immunoresponse against certain antigenic determinants on pancreatic B cells. Furthermore, 5C12 has not only qualitatively and quantitatively improved diagnostic methodology, but it may also provide new reagents useful to the treatment and prevention of type 1 diabetes.
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PMID:[An analysis of islet cell surface antigen defined by monoclonal islet cell surface antibody 5C12]. 354 94

Non-obese diabetic mice display a syndrome with dramatic clinical and pathological features similar to those of Type 1 (insulin-dependent) diabetes in man. Circulating autoantibodies to the surface of islet cells were demonstrated in some of these mice by a protein A radioligand assay. To produce monoclonal antibodies to islet cell surface antigens, therefore, we took the spleens of non-obese diabetic mice, transferred the spleen cells into non-immunized recipient mice, which were made immunologically incompetent by a large dose of X-irradiation, and then fused their lymphocytes with FO mouse myeloma cells. After screening the resultant hybrids, one stable hybridoma (3A4) that produced a monoclonal antibody (IgG1) specifically bound to the surface of islet cells was obtained. The purified monoclonal antibody was bound to the surface of transplantable Syrian golden hamster insulinoma cells sevenfold more than control antibody. Adsorption of the antibody on mouse spleen lymphocytes or thymocytes resulted in only a slight decrease in 125I-protein A binding to insulinoma cells. This antibody also reacted with the surface of mouse and rat islet cells, but not with that of rat spleen cells or hepatocytes. A spectrophotometric assay for peroxidase activity demonstrated that six times more peroxidase bound to insulinoma cells incubated with the antibody than to cells treated with control antibody. Furthermore, this antibody could be visually detected in the immunoenzymatic labelling of the surface of insulinoma cells. In summary, we have developed a novel method of producing monoclonal antibodies to the surface of islet cells for probing into the pathogenesis of Type 1 diabetes.
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PMID:Production of monoclonal antibodies to islet cell surface antigens using hybridization of spleen lymphocytes from non-obese diabetic mice. 637 47

We have developed hybridomas producing anti-islet cell monoclonal autoantibodies (IC-MC auto Ab), by fusion of splenocytes from C57BLKsJ db/db diabetic mice with the SP2/O-Ag 14 myeloma. These IC-MC auto Ab were screened by an enzyme-linked immunosorbent assay, for their binding-ability to RINm5F insulinoma cells. Twenty IC-MC auto Ab were produced, which have differing immunoglobulin isotypes. Four of them induced a complement-dependent lysis of RINm5F cells in vitro, while the others did not. These two populations of auto Ab reflect the duality found in the intact db/db mouse. Immunoperoxidase procedures demonstrated that IC-MC auto Ab bound specifically to beta cell antigens of control pancreatic sections, in a similar pattern as auto Ab spontaneously "trapped" in the islets of db/db mice. Electron microscopic studies with an immunogold staining suggested that target antigens for IC-MC auto Ab were predominantly located in the cytoplasmic matrix of beta cells and, to a lesser extent, on their membranes. These antibodies represent powerful reactives for the studies concerning with the pathogeny of diabetes.
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PMID:Monoclonal anti-islet cell autoantibodies from C57BLKsJ db/db diabetic mice. 638 27


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