scholarly journals Biosynthesis of the carbohydrate portions of immunoglobulin M

1971 ◽  
Vol 125 (1) ◽  
pp. 235-240 ◽  
Author(s):  
R. M. E. Parkhouse ◽  
Fritz Melchers

Incorporations of radioactive mannose, galactose and fucose into MOPC 104E mouse plasma-cell tumour suspensions suggest a stepwise addition of carbohydrate residues to immunoglobulin M (IgM) during the process of secretion. Mannose and glucosamine residues are added at an early stage, whereas galactose and fucose are added just before, or at the time that, IgM leaves the cell. Free light chains secreted in excess by the same tumour cells incubated with mannose, galactose or fucose contained barely detectable amounts of radioactivity.

1983 ◽  
Vol 3 (6) ◽  
pp. 1077-1085
Author(s):  
L C Chen ◽  
S A Courtneidge ◽  
J M Bishop

The production of immunoglobulin by six cell lines derived from bursal tumors induced by avian leukosis virus follows two general patterns: (i) three cell lines that have been extensively passaged in culture synthesize and secrete light chains only; (ii) three cell lines that are recently isolated produce and secrete monomeric immunoglobulin M in addition to free light chains. All six cell lines synthesize and secrete both glycosylated and unglycosylated forms of light chain. We conclude that the cell lines established from lymphomas induced by avian leukosis virus represent relatively mature, but possibly abnormal, stages in the development of chicken B-lymphocytes. The immunoglobulin M produced by the cell lines failed to form detectable immune complexes with avian leukosis virus. It therefore appears that the immunoglobulin M is not directed against viral antigens and that autogenous antigenic stimulus cannot account for the sustained growth of the neoplastic B-lymphocytes.


2020 ◽  
Vol 51 (6) ◽  
pp. 592-600 ◽  
Author(s):  
Gurmukh Singh ◽  
Roni Bollag

Abstract Objective Measurement of monoclonal immunoglobulins is a reliable estimate of the plasma cell tumor mass. About 15% of plasma cell myelomas secrete light chains only. The concentration of serum free light chains is insufficient evidence of the monoclonal light chain burden. A sensitive quantitative estimate of serum free monoclonal light chains could be useful for monitoring patients with light chain myeloma. We describe such an assay that does not require mass-spectrometry equipment or expertise. Methods Serum specimens from patients with known light chain myelomas and controls were subjected to ultrafiltration through a membrane with pore size of 50 kDa. The filtrate was concentrated and tested by immunofixation electrophoresis. The relative area under the monoclonal peak, compared to that of the total involved light chain composition, was estimated by densitometric scanning of immunofixation gels. The proportion of the area occupied by the monoclonal peak in representative densitometric scans was used to arrive at the total serum concentration of the monoclonal serum free light chains. Results Using an ultracentrifugation and concentration process, monoclonal serum free light chains were detectable, along with polyclonal light chains, in all 10 patients with active light chain myelomas. Monoclonal light chains were identified in serum specimens that did not reveal monoclonal light chains by conventional immunofixation electrophoresis. The limit of detection by this method was 1.0 mg/L of monoclonal serum free light chains. Conclusion The method described here is simple enough to be implemented in academic medical center clinical laboratories and does not require special reagents, equipment, or expertise. Even though urine examination is the preferred method for the diagnosis of light chain plasma cell myelomas, measurement of the concentration of serum free light chains provides a convenient, albeit inadequate, way to monitor the course of disease. The method described here allows effective electrophoretic differentiation of monoclonal serum free light chain from polyclonal serum free light chains and provides a quantitation of the monoclonal serum free light chains in monitoring light chain monoclonal gammopathies.


Blood ◽  
2010 ◽  
Vol 116 (9) ◽  
pp. 1397-1404 ◽  
Author(s):  
Eliot C. Heher ◽  
Nelson B. Goes ◽  
Thomas R. Spitzer ◽  
Noopur S. Raje ◽  
Benjamin D. Humphreys ◽  
...  

Plasma cell dyscrasias are frequently encountered malignancies often associated with kidney disease through the production of monoclonal immunoglobulin (Ig). Paraproteins can cause a remarkably diverse set of pathologic patterns in the kidney and recent progress has been made in explaining the molecular mechanisms of paraprotein-mediated kidney injury. Other recent advances in the field include the introduction of an assay for free light chains and the use of novel antiplasma cell agents that can reverse renal failure in some cases. The role of stem cell transplantation, plasma exchange, and kidney transplantation in the management of patients with paraprotein-related kidney disease continues to evolve.


1983 ◽  
Vol 3 (6) ◽  
pp. 1077-1085 ◽  
Author(s):  
L C Chen ◽  
S A Courtneidge ◽  
J M Bishop

The production of immunoglobulin by six cell lines derived from bursal tumors induced by avian leukosis virus follows two general patterns: (i) three cell lines that have been extensively passaged in culture synthesize and secrete light chains only; (ii) three cell lines that are recently isolated produce and secrete monomeric immunoglobulin M in addition to free light chains. All six cell lines synthesize and secrete both glycosylated and unglycosylated forms of light chain. We conclude that the cell lines established from lymphomas induced by avian leukosis virus represent relatively mature, but possibly abnormal, stages in the development of chicken B-lymphocytes. The immunoglobulin M produced by the cell lines failed to form detectable immune complexes with avian leukosis virus. It therefore appears that the immunoglobulin M is not directed against viral antigens and that autogenous antigenic stimulus cannot account for the sustained growth of the neoplastic B-lymphocytes.


2009 ◽  
Vol 30 (1) ◽  
pp. 21-23
Author(s):  
Arthur R. Bradwell ◽  
Colin A. Hutchison ◽  
Paul Cockwell

2010 ◽  
Vol 29 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Vesna Radović

Recommendations for Use of Free Light Chain Assay in Monoclonal GammopathiesThe serum immunoglobulin free light chain assay measures levels of free κ and λ immunoglobulin light chains. There are three major indications for the free light chain assay in the evaluation and management of multiple myeloma and related plasma cell disorders. In the context of screening, the serum free light chain assay in combination with serum protein electrophoresis and immunofixation yields high sensitivity, and negates the need for 24-hour urine studies for diagnoses other than light chain amyloidosis. Second, the baseline free light chains measurement is of major prognostic value in virtually every plasma cell disorder. Third, the free light chain assay allows for quantitative monitoring of patients with oligosecretory plasma cell disorders, including AL, oligosecretory myeloma, and nearly twothirds of patients who had previously been deemed to have non-secretory myeloma. In AL patients, serial free light chains measurements outperform protein electrophoresis and immunofixation. In oligosecretory myeloma patients, although not formally validated, serial free light chains measurements reduce the need for frequent bone marrow biopsies. In contrast, there are no data to support using free light chain assay in place of 24-hour urine electrophoresis for monitoring or for serial measurements in plasma cell disorders with measurable disease by serum or urine electrophoresis.


1971 ◽  
Vol 125 (1) ◽  
pp. 241-247 ◽  
Author(s):  
Fritz Melchers

Incorporation of radioactive fucose into the immunoglobulin G1 myeloma protein secreted by mouse plasma-cell tumour MOPC 21 is stereospecific for the l-isomer. Heavy chains of the secreted form of the myeloma protein carry 90% of the label in fucose residues of their carbohydrate moieties. A small but significant amount of the intracellular immunoglobulin G1 of the mouse plasma-cell tumour MOPC 21 appears to be labelled. Serum in the incubation medium supplies low-molecular-weight diffusible substances necessary to maintain continuous secretion of fucose-labelled myeloma protein beyond 2–3h, and of leucine-labelled myeloma protein beyond 6–8h. In medium containing extensively dialysed serum the secretion of leucine- and fucose-labelled myeloma protein can be restored by the addition of 250μm-d-mannose, 250μm-d-galactose and 250μm-glucosamine. Synthesis and secretion appear to be facilitated in the presence of these sugars, although secretion of myeloma protein devoid of terminal fucose residues is possible for a limited time-period.


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