scholarly journals Mutations affecting the structure and function of immunoglobulin M.

1982 ◽  
Vol 2 (9) ◽  
pp. 1033-1043 ◽  
Author(s):  
M J Shulman ◽  
C Heusser ◽  
C Filkin ◽  
G Köhler
Keyword(s):  
Mutant Cell ◽  
Immunoglobulin M ◽  
Structural Basis ◽  
Light Chains ◽  
Partial Deletion ◽  
Structural Alterations ◽  
Specific Immunoglobulin ◽  
Synthesis And Processing ◽  
And Function ◽  
Abnormal Glycosylation

Using a hybridoma cell line which secretes hapten-specific immunoglobulin M (IgM), we have isolated a variety of mutants which produce abnormal immunoglobulin. Immunoglobulin was tested for the size and composition of the component heavy and light chains and for variable and constant region related functional and serological activities. Some mutants secrete IgM which seems to be defective in hapten binding; others make IgM which appears not to activate complement. Many of the mutants secrete monomeric as opposed to pentameric IgM. In some cases, the defect apparently correlates with structural alterations in the mu heavy chain: partial deletion, polypeptide addition, and abnormal glycosylation have been observed. These mutant cell lines provide a means of identifying the structural basis of IgM function and of studying the biochemistry of IgM synthesis and processing.

Mutations affecting the structure and function of immunoglobulin M

1982 ◽  
Vol 2 (9) ◽  
pp. 1033-1043
Author(s):  
M J Shulman ◽  
C Heusser ◽  
C Filkin ◽  
G Köhler
Keyword(s):  
Mutant Cell ◽  
Immunoglobulin M ◽  
Structural Basis ◽  
Light Chains ◽  
Partial Deletion ◽  
Structural Alterations ◽  
Specific Immunoglobulin ◽  
Synthesis And Processing ◽  
And Function ◽  
Abnormal Glycosylation

Using a hybridoma cell line which secretes hapten-specific immunoglobulin M (IgM), we have isolated a variety of mutants which produce abnormal immunoglobulin. Immunoglobulin was tested for the size and composition of the component heavy and light chains and for variable and constant region related functional and serological activities. Some mutants secrete IgM which seems to be defective in hapten binding; others make IgM which appears not to activate complement. Many of the mutants secrete monomeric as opposed to pentameric IgM. In some cases, the defect apparently correlates with structural alterations in the mu heavy chain: partial deletion, polypeptide addition, and abnormal glycosylation have been observed. These mutant cell lines provide a means of identifying the structural basis of IgM function and of studying the biochemistry of IgM synthesis and processing.

Biochemical genetics of the mouse IgM system

1984 ◽  
Vol 62 (4) ◽  
pp. 217-224 ◽  
Author(s):  
Marc J. Shulman ◽  
Robert G. Hawley ◽  
Atsuo Ochi ◽  
W. O. T. Baczynsky ◽  
Catherine Collins ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Heavy Chain ◽  
Mutant Cell ◽  
Immunoglobulin M ◽  
Structural Basis ◽  
Deletion Mutants ◽  
Transfer System ◽  
Biochemical Genetics ◽  
Chain Synthesis

Using a mouse hybridoma system, we have developed methods of isolating a variety of mutant cell lines in which immunoglobulin function or synthesis is defective. The analysis of mutants defective in κ chain synthesis has defined a class of murine transposons. The deletion mutants produce immunoglobulin M (IgM) bearing μ heavy chain fragments and provide information on the requirements of IgM assembly and μ gene expression. We also describe a transfer system for the μ and κ genes which will be useful in analyzing the structural basis of IgM function.

TBE in Sweden

2020 ◽  
Keyword(s):  
Genetic Characterization ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Second Phase ◽  
Serum Samples ◽  
Tick Borne Encephalitis ◽  
Specific Immunoglobulin ◽  
Tick Borne Encephalitis Virus ◽  
First Time

Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.

scholarly journals Diagnosis of Dengue Virus Infection by Detection of Specific Immunoglobulin M (IgM) and IgA Antibodies in Serum and Saliva

2003 ◽  
Vol 10 (2) ◽  
pp. 317-322 ◽  
Author(s):  
Angel Balmaseda ◽  
María G. Guzmán ◽  
Samantha Hammond ◽  
Guillermo Robleto ◽  
Carolina Flores ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Immunoglobulin M ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Serum Samples ◽  
Diagnostic Modality ◽  
Iga Antibodies ◽  
Specific Immunoglobulin ◽  
Feasible Alternative

ABSTRACT To evaluate alternative approaches to the serological diagnosis of dengue virus (DEN) infection, the detection of DEN-specific immunoglobulin M (IgM) and IgA antibodies in serum and saliva specimens was assessed in 147 patients with symptoms of DEN infection seen at the Ministry of Health in Nicaragua. Seventy-two serum samples were determined to be positive for anti-DEN antibodies by IgM capture enzyme-linked immunosorbent assay, the routine diagnostic procedure. Serum and saliva specimens were obtained from 50 healthy adults as additional controls. IgM was detected in the saliva of 65 of the 72 serum IgM-positive cases, 6 of the 75 serum IgM-negative cases, and none of the control group, resulting in a sensitivity of 90.3% and a specificity of 92.0% and demonstrating that salivary IgM is a useful diagnostic marker for DEN infection. Detection of IgA in serum may be another feasible alternative for the diagnosis of DEN infection, with serum IgA found in 68 (94.4%) of the IgM-positive cases. In contrast, detection of IgA in saliva was not found to be a useful tool for DEN diagnosis in the present study. Further studies of the kinetics of antibody detection in another set of 151 paired acute- and convalescent-phase serum samples showed that DEN-specific IgA antibodies were detected in more acute-phase samples than were IgM antibodies. Thus, we conclude that DEN-specific IgA in serum is a potential diagnostic target. Furthermore, given that saliva is a readily obtainable, noninvasive specimen, detection of DEN-specific salivary IgM should be considered a useful, cheaper diagnostic modality with similar sensitivity and specificity to IgM detection in serum.

scholarly journals Cervical Cat Scratch Disease Lymphadenitis in a Patient with Immunoglobulin M Antibodies to Toxoplasma gondii

2002 ◽  
Vol 9 (2) ◽  
pp. 496-498
Author(s):  
Mardjan Arvand ◽  
Ilkay Kazak ◽  
Sergije Jovanovic ◽  
Hans-Dieter Foss ◽  
Oliver Liesenfeld
Keyword(s):  
Toxoplasma Gondii ◽  
Clinical Symptoms ◽  
Bartonella Henselae ◽  
Cervical Lymphadenopathy ◽  
Immunoglobulin M ◽  
Cat Scratch Disease ◽  
Specific Immunoglobulin ◽  
Acute Toxoplasmosis

ABSTRACT We report on a young patient with chronic cervical lymphadenopathy and serological and histological evidence for infection with Bartonella henselae and Toxoplasma gondii. Serological follow-up studies, including testing for avidity of Toxoplasma-specific immunoglobulin G antibodies, assisted in the determination of the cause of the acute lymphadenitis. Our results suggest that the clinical symptoms were most likely due to cat scratch disease rather than to acute toxoplasmosis.

Immunological phenotype of lymphomas induced by avian leukosis viruses

1983 ◽  
Vol 3 (6) ◽  
pp. 1077-1085
Author(s):  
L C Chen ◽  
S A Courtneidge ◽  
J M Bishop
Keyword(s):  
B Lymphocytes ◽  
Cell Lines ◽  
Light Chain ◽  
Avian Leukosis Virus ◽  
Immunoglobulin M ◽  
Light Chains ◽  
Free Light Chains ◽  
Viral Antigens ◽  
Immunological Phenotype ◽  
Avian Leukosis Viruses

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.

scholarly journals Significance of specific immunoglobulin M in the chronological diagnosis of 38 cases of toxoplasmic lymphadenopathy.

1989 ◽  
Vol 27 (9) ◽  
pp. 2133-2135 ◽  
Author(s):  
V Del Bono ◽  
A Canessa ◽  
P Bruzzi ◽  
M A Fiorelli ◽  
A Terragna
Keyword(s):  
Immunoglobulin M ◽  
Specific Immunoglobulin

scholarly journals Timing of Development of Measles-Specific Immunoglobulin M and G after Primary Measles Vaccination

1999 ◽  
Vol 6 (2) ◽  
pp. 178-180 ◽  
Author(s):  
Rita F. Helfand ◽  
Senait Kebede ◽  
Howard E. Gary ◽  
Hagos Beyene ◽  
William J. Bellini
Keyword(s):  
Positive Result ◽  
Measles Virus ◽  
Primary Vaccination ◽  
Immunoglobulin M ◽  
Measles Vaccine ◽  
Wild Type ◽  
Specific Antibodies ◽  
Specific Immunoglobulin ◽  
Measles Vaccination ◽  
Antibody Capture

ABSTRACT A standard method for diagnosing measles is to detect measles-specific immunoglobulin M (IgM) in the serum of infected persons. Interpreting a positive IgM result from a person with suspected measles can be difficult if the person has recently received a measles vaccine. We have previously demonstrated that measles-specific IgM may persist for at least 8 weeks after primary vaccination, but it is unknown how quickly IgM appears. This study determined the timing of the rise of measles-specific IgM and IgG after primary measles vaccination with Schwartz vaccine. Two hundred eighty 9-month-old children from Ethiopia presenting for routine measles vaccination were enrolled. Sera were collected before and either 1, 2, 3, or 4 weeks after vaccination and tested for measles-specific antibodies by an IgM capture enzyme immunoassay (EIA) and by an indirect IgG EIA. A total of 209 of the 224 children who returned for the second visit had prevaccination sera that were both IgM and IgG negative. The postvaccination IgM positivity rates for these 209 children were 2% at 1 week, 61% at 2 weeks, 79% at 3 weeks, and 60% at 4 weeks. The postvaccination IgG positivity rates were 0% at 1 week, 14% at 2 weeks, 81% at 3 weeks, and 85% at 4 weeks. We conclude that an IgM-positive result obtained by this antibody capture EIA is difficult to interpret if serum is collected between 8 days and 8 weeks after vaccination; in this situation, the diagnosis of measles should be based on an epidemiologic linkage to a confirmed case or on the detection of wild-type measles virus.

scholarly journals Structural basis for recognition of human 7SK long noncoding RNA by the La-related protein Larp7

2018 ◽  
Vol 115 (28) ◽  
pp. E6457-E6466 ◽  
Author(s):  
Catherine D. Eichhorn ◽  
Yuan Yang ◽  
Lucas Repeta ◽  
Juli Feigon
Keyword(s):  
Noncoding Rna ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Transcription Elongation ◽  
Structural Basis ◽  
Titration Calorimetry ◽  
Rna Recognition Motif ◽  
Related Protein ◽  
Binding Interface ◽  
And Function

The La and the La-related protein (LARP) superfamily is a diverse class of RNA binding proteins involved in RNA processing, folding, and function. Larp7 binds to the abundant long noncoding 7SK RNA and is required for 7SK ribonucleoprotein (RNP) assembly and function. The 7SK RNP sequesters a pool of the positive transcription elongation factor b (P-TEFb) in an inactive state; on release, P-TEFb phosphorylates RNA Polymerase II to stimulate transcription elongation. Despite its essential role in transcription, limited structural information is available for the 7SK RNP, particularly for protein–RNA interactions. Larp7 contains an N-terminal La module that binds UUU-3′OH and a C-terminal atypical RNA recognition motif (xRRM) required for specific binding to 7SK and P-TEFb assembly. Deletion of the xRRM is linked to gastric cancer in humans. We report the 2.2-Å X-ray crystal structure of the human La-related protein group 7 (hLarp7) xRRM bound to the 7SK stem-loop 4, revealing a unique binding interface. Contributions of observed interactions to binding affinity were investigated by mutagenesis and isothermal titration calorimetry. NMR 13C spin relaxation data and comparison of free xRRM, RNA, and xRRM–RNA structures show that the xRRM is preordered to bind a flexible loop 4. Combining structures of the hLarp7 La module and the xRRM–7SK complex presented here, we propose a structural model for Larp7 binding to the 7SK 3′ end and mechanism for 7SK RNP assembly. This work provides insight into how this domain contributes to 7SK recognition and assembly of the core 7SK RNP.

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