Glycopeptides of immunoglobulins. Investigations on IgA myeloma globulins.
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ABSTRACT:
SUBMITTER: Clamp JR
PROVIDER: S-EPMC1270389 | biostudies-other | 1967 Apr
REPOSITORIES: biostudies-other
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Project description:IntroductionMultiple myeloma is still incurable in most cases. Polyclonal anti T lymphocyte globulins (ATG) have been reported to kill human myeloma cells in vitro and in mouse models.MethodsAnti-human-myeloma globulins (AMG) were produced by immunizing rabbits with human myeloma cell lines RPMI-8226 (AMG-8226) or KMS-12-BM (AMG-12-BM). Cytotoxicity of the polyclonal antibodies was analyzed in vitro and in a xenograft NOD-SCID mouse model.ResultsBoth AMG had stronger cytotoxicity against myeloma cells compared to ATG. In primary T cells, AMG-8226 showed greater complement-dependent cytotoxicity (CDC) than ATG, whereas complement-independent cytotoxicity did not differ. Effects on non-hematopoietic cell lines were also similar. Competitive blocking assays revealed fourfold more antibodies against CD38 in AMG-8226 compared to ATG. Low concentrations of AMG-8226 and ATG increased ADCC. At higher concentrations, ATG inhibited ADCC more potently than AMG-8226. Combinations of ATG and AMG-8226 with melphalan or bortezomib showed additive to synergistic cytotoxicity on myeloma cells. The cytotoxic effects of AMG and ATG were confirmed in the xenograft NOD-SCID mouse model.ConclusionOur data show more potent antimyeloma effects of AMG compared to ATG. These results lay the ground for the development of polyclonal antibodies for the treatment of multiple myeloma.
| S-EPMC5341857 | biostudies-literature
Project description:For investigations on the biological functions of oligosaccharides and peptidomimetics, new asparagine-based mono- and disaccharides containing glycopeptides were prepared in solution. The applicability of two common peptide coupling reagents, using an orthogonal Fmoc/t-Bu strategy along with acetyl protecting groups for the carbohydrate moiety, was studied. Thus, the prepared libraries of glycopeptides were designed as model systems of cell surfaces for future investigations by combined preparative mass spectroscopy and scanning tunneling microscopy (STM) using soft-landing electrospray beam deposition (ES-IBD), on metal surfaces.
| S-EPMC7214877 | biostudies-literature
Project description:Little is known about the impact of multiple myeloma (MM) treatment on uninvolved immunoglobulins (Ig). We identified 448 patients who received high-dose dexamethasone (HD-DEX), lenalidomide and dexamethasone (RD), bortezomib and dexamethasone (VD), bortezomib, cyclophosphamide and dexamethasone (VCD) or bortezomib, lenalidomide and dexamethasone (VRD) for newly diagnosed MM at our institution between 2000 and 2013, and who had available data on absolute lymphocyte count (ALC) and quantitative uninvolved Ig at baseline and at the end of four cycles of therapy. Changes in ALC and uninvolved Ig were significantly different across treatments, with VCD and HD-DEX producing reductions in uninvolved Ig, and RD, VD and VRD leading to increases in uninvolved Ig. In addition, treatment with RD, VD and VRD was independently associated with higher odds of achieving a ⩾25% increase in or normalization of the primary uninvolved Ig on multivariate analysis. Although achievement of a humoral response in the primary uninvolved Ig was associated with a higher odds of achieving VGPR or better after four cycles of therapy, it was not associated with improved overall survival. These data highlight the different mechanisms of action of MM drugs and point toward a possible role for the use of VCD in treating antibody-mediated autoimmune disease.
| S-EPMC5584483 | biostudies-literature
Project description:The carbohydrate content of an A myeloma globulin was investigated. The carbohydrate content was found to be unchanged when the protein was isolated from the patient over a period of 18 months. The various polymeric forms of the protein contained similar proportions of carbohydrate. The A myeloma globulin contained approx. 2 residues of 6-deoxy-l-galactose (l-fucose), 14-15 of d-mannose, 12-13 of d-galactose, 12-13 of 2-acetamido-2-deoxy-d-glucose (N-acetyl-d-glucosamine), 6 of 2-acetamido-2-deoxy-d-galactose (N-acetyl-d-galactosamine) and 5 of N-acetylneuraminic acid (sialic acid), and these were distributed between six oligosaccharide units all of which were present on the heavy polypeptide chains. The oligosaccharide units showed two kinds of heterogeneity, which have been termed central and peripheral. Central heterogeneity was shown by the presence of three completely different core units, which had the following compositions: (1) 3 residues of d-galactose and 3 of 2-acetamido-2-deoxy-d-galactose, joined to protein by an O-glycosidic linkage between acetamidohexose and serine; (2) 3 residues of d-mannose, 2 of d-galactose and 3 of 2-acetamido-2-deoxy-d-glucose, joined to protein by an N-glycosidic linkage between acetamidohexose and aspartic acid; (3) 4 residues of d-mannose and 3 of 2-acetamido-2-deoxy-d-glucose with a linkage similar to that in (2). The core oligosaccharide units showed peripheral heterogeneity in the attachment of 6-deoxy-l-galactose, 2-acetamido-2-deoxy-d-glucose and N-acetylneuraminic acid. Tentative structures are proposed for these various types of oligosaccharide unit. Glycopeptides were isolated in which the sialic acid content exceeded that of d-galactose. Explanations are given for the electrophoretic mobility and staining characteristics of the various glycopeptides.
| S-EPMC1198669 | biostudies-other
Project description:This retrospective study presents our 4-year experience of preemptive treatment of early anti-HLA donor specific antibodies with IgA- and IgM-enriched immunoglobulins. We compared outcomes between patients with antibodies and treatment (case patients) and patients without antibodies (control patients). Records of patients transplanted at our institution between March 2013 and November 2017 were reviewed. The treatment protocol included one single 2 g/kg immunoglobulin infusion followed by successive 0.5 g/kg infusions for a maximum of 6 months, usually combined with a single dose of anti-CD20 antibody and, in case of clinical rejection or positive crossmatch, with plasmapheresis or immunoabsorption. Among the 598 transplanted patients, 128 (21%) patients formed the case group and 452 (76%) the control group. In 116 (91%) patients who completed treatment, 106 (91%) showed no antibodies at treatment end. Fourteen (13%) patients showed antibody recurrence thereafter. In case versus control patients and at 4-year follow-up, respectively, graft survival (%) was 79 versus 81 (P = .59), freedom (%) from biopsy-confirmed rejection 57 versus 53 (P = .34), and from chronic lung allograft dysfunction 82 versus 78 (P = .83). After lung transplantation, patients with early donor-specific antibodies and treated with IgA- and IgM-enriched immunoglobulins had 4-year graft survival similar to patients without antibodies and showed high antibody clearance.
| S-EPMC6585979 | biostudies-literature
Project description:The majority of multiple myeloma (MM) patients have high levels of monoclonal immunoglobulin in the serum and/or urine and suppressed levels of the uninvolved immunoglobulins. The prognostic significance of this phenomenon has not been assessed sufficiently. In this study, our aim is to evaluate the prognostic significance of uninvolved immunoglobulin suppression measured by nephelometry in patients with new symptomatic MM and the association with other features of the disease.Between August 2003 and February 2015, 137 patients who were referred for the treatment of newly diagnosed symptomatic myeloma to the Hematology Department polyclinics of the İstanbul University İstanbul Faculty of Medicine were prospectively included and had available pretreatment immunoglobulin levels measured by nephelometry.Suppression of at least one uninvolved immunoglobulin was observed in 87% of patients and this situation was slightly more common in patients with immunoglobulin A myeloma but had no statistical significance (p>0.05). Uninvolved immunoglobulin suppression was also more common among patients who had bone marrow plasma cell infiltration of ≥40% and presented with anemia and hypercalcemia (p<0.05). The overall survival time was shorter in patients with positive calcium-renal-anemia-bone criteria and International Staging System stage 3 compared with others (p<0.05). Factors that were independently associated with inferior survival in the multivariate analysis included patients with estimated glomerular filtration rate of <60 mL/min, age of >65 years, lactate dehydrogenase of >300 IU/L, bone marrow plasma cells of ≥40%, and β2-microglobulin of >3.5 mg/dL (p<0.05).In this study, 13.1% of MM patients had preserved levels of uninvolved immunoglobulins. We observed that patients who had preserved uninvolved immunoglobulin levels had better treatment responses and better pathologic signs, but statistical significance could not be shown. Conversely, patients with suppression of even one of the uninvolved immunoglobulins had a shorter survival, but similarly, statistical significance could not be shown.
| S-EPMC5440864 | biostudies-other
Project description:Immunoglobulin A (IgA)-albumin complexes may be associated with pathophysiology of multiple myeloma, although the etiology is not clear. Detailed structural analyses of these protein-protein complexes may contribute to our understanding of the pathophysiology of this disease. We analyzed the structure of the IgA-albumin complex using various electrophoresis, mass spectrometry, and in silico techniques. The data based on the electrophoresis and mass spectrometry showed that IgA in the sera of patients was dimeric, linked via the J chain. Only dimeric IgA can bind to albumin molecules leading to IgA-albumin complexes, although both monomeric and dimeric forms of IgA were present in the sera. Molecular interaction analyses in silico implied that dimeric IgA and albumin interacted not only via disulfide bond formation, but also via noncovalent bonds. Disulfide bonds were predicted between Cys34 of albumin and Cys311 of IgA, resulting in an oxidized form of albumin. Furthermore, complex formation prolongs the half-life of IgA molecules in the IgA-albumin complex, leading to excessive glycation of IgA molecules and affects the accumulation of IgA in serum. These findings may demonstrate why complications such as hyperviscosity syndrome occur more often in patients with IgA dimer producing multiple myeloma.
| S-EPMC7916671 | biostudies-literature
Project description:BACKGROUND:The administration of endovenous immunoglobulins in patients with septic shock could be beneficial and preparations enriched with IgA and IgM (ivIgGAM) seem to be more effective than those containing only IgG. In a previous study Berlot et al. demonstrated that early administration of ivIgGAM was associated with lower mortality rate. We studied a larger population of similar patients aiming either to confirm or not this finding considering also the subgroup of patients with septic shock by multidrug-resistant (MDR) pathogens. METHODS:Adult patients with septic shock in intensive care unit (ICU) treated with ivIgGAM from August 1999 to December 2016 were retrospectively examined. Collected data included the demographic characteristics of the patients, the diagnosis at admission, SOFA, SAPS II and Murray Lung Injury Score (LIS), characteristics of the primary infection, the adequacy of antimicrobial therapy, the delay of administration of ivIgGAM from the ICU admission and the outcome at the ICU discharge. Parametric and nonparametric tests and logistic regression were used for statistic analysis. RESULTS:During the study period 107 (30%) of the 355 patients died in ICU. Survivors received the ivIgGAM earlier than nonsurvivors (median delay 12 vs 14 h), had significantly lower SAPS II, SOFA and LIS at admission and a lower rate of MDR- and fungal-related septic shock. The appropriateness of the administration of antibiotics was similar in survivors and nonsurvivors (84 vs 79%, respectively, p: n.s). The delay in the administration of ivIgGAM from the admission was associated with in-ICU mortality (odds ratio per 1-h increase?=?1.0055, 95% CI 1.003-1.009, p?<?0.001), independently of SAPS II, LIS, cultures positive for MDR pathogens or fungi and onset of septic shock. Only 46 patients (14%) had septic shock due to MDR pathogens; 21 of them (46%) died in ICU. Survivors had significantly lower SAPS II, SOFA at admission and delay in administration of ivIgGAM than nonsurvivors (median delay 18 vs 66 h). Even in this subgroup the delay in the administration of ivIgGAM from the admission was associated with an increased risk of in-ICU mortality (odds ratio 1.007, 95% CI 1.0006-1.014, p?=?0.048), independently of SAPS II. CONCLUSIONS:Earlier administration of ivIgGAM was associated with decreased risk of in-ICU mortality both in patients with septic shock caused by any pathogens and in patients with MDR-related septic shock.
| S-EPMC6288102 | biostudies-literature
Project description: Not available
| S-EPMC7158990 | biostudies-literature
Project description:The treatment of many diseases such as cancer requires the use of drugs that can cause severe side effects. Off-target toxicity can often be reduced simply by directing the drugs specifically to sites of diseases. Amidst increasingly sophisticated methods of targeted drug delivery, we observed that Nature has already evolved elegant means of sending biological molecules to where they are needed. One such example is corticosteroid binding globulin (CBG), the major carrier of the anti-inflammatory hormone, cortisol. Targeted release of cortisol is triggered by cleavage of CBG's reactive centre loop by elastase, a protease released by neutrophils in inflamed tissues. This work aimed to establish the feasibility of exploiting this mechanism to carry therapeutic agents to defined locations. The reactive centre loop of CBG was altered with site-directed mutagenesis to favour cleavage by other proteases, to alter the sites at which it would release its cargo. Mutagenesis succeeded in making CBG a substrate for either prostate specific antigen (PSA), a prostate-specific serine protease, or thrombin, a key protease in the blood coagulation cascade. PSA is conspicuously overproduced in prostatic hyperplasia and is, therefore, a good way of targeting hyperplastic prostate tissues. Thrombin is released during clotting and consequently is ideal for conferring specificity to thrombotic sites. Using fluorescence-based titration assays, we also showed that CBG can be engineered to bind a new compound, thyroxine-6-carboxyfluorescein, instead of its physiological ligand, cortisol, thereby demonstrating that it is possible to tailor the hormone binding site to deliver a therapeutic drug. In addition, we proved that the efficiency with which CBG releases bound ligand can be increased by introducing some well-placed mutations. This proof-of-concept study has raised the prospect of a novel means of targeted drug delivery, using the serpin conformational change to combat the problem of off-target effects in the treatment of diseases.
| S-EPMC4245140 | biostudies-literature