scholarly journals Biosynthesis of immunoglobulin A (IgA). Secretion and addition of carbohydrate to monomer and polymer forms of a mouse myeloma protein

1973 ◽  
Vol 136 (3) ◽  
pp. 589-596 ◽  
Author(s):  
E. Della Corte ◽  
R. M. E. Parkhouse

Cell suspensions of mouse plasma-cell tumour MOPC 315 secreting predominantly IgA (immunoglobulin A) monomer and dimer were incubated with radioactive leucine, mannose, galactose and fucose for various periods of time. The amounts of secreted and intracellular immunoglobulins were measured by co-precipitation with specific antibody, and the molecular species present were assessed by electrophoresis in polyacrylamide gels. Analysis of the secreted myeloma protein demonstrated that monomer and dimer IgA molecules are identical with respect to carbohydrate composition and rate of secretion. Within the cell, the myeloma protein is almost entirely accounted for by monomer units which either leave the cell as such or are polymerized with the addition of J chain close to the time of secretion. The results support the concept of a stepwise addition of carbohydrate residues to IgA immunoglobulin during the process of secretion. Similar patterns of carbohydrate assembly were found for the monomer or dimer molecules. Mannose residues are added at an early stage, whereas fucose is added close to the time of secretion. Galactose is also added early, but some may also be incorporated at a later stage. Control of IgA polymerization is considered unlikely to reflect regulation at the level of carbohydrate addition, and it is suggested that the critical controlling factor is the J chain.

1973 ◽  
Vol 136 (3) ◽  
pp. 607-609 ◽  
Author(s):  
R. M. E. Parkhouse ◽  
E. Della Corte

Cell suspensions of mouse plasma-cell tumours secreting IgA (immunoglobulin A) and IgM (immunoglobulin M) were incubated with radioactive leucine for various periods of time. The secreted immunoglobulins were precipitated from the culture medium with specific rabbit antisera to determine the relative distribution of radioactivity among the different molecular species, and to estimate the fraction of total radioactivity in the J chain. For IgM-secreting cells there is a balanced synthesis of 7S subunits and J chains, and the secreted product is uniformly assembled to the pentamer. In cells secreting IgA, however, the results demonstrate that the pool of intracellular J chain is less than the intracellular IgA pool. The concentration of J chain is therefore limiting and is less than the requirement for complete polymerization. The major factor that determines whether an intracellular monomer is secreted as such or is polymerized with the addition of J chain is therefore the amount of intracellular J chain. When this is limiting, as it is in cells secreting IgA, then monomer will be secreted.


1966 ◽  
Vol 123 (4) ◽  
pp. 707-721 ◽  
Author(s):  
Noel L. Warner ◽  
Leonard A. Herzenberg ◽  
Gideon Goldstein

Further analysis of the isoantigens (allotypes) of 2 classes of normal mouse immunoglobulins, γG2a and γG2b, has shown a minimum of 10 specificities for the Ig-1 locus (controlling γG2a-antigens) and 3 specificities for the Ig-3 locus (controlling γG2b-antigens). Three γG2-myeloma proteins of plasma cell tumors induced in (NZB x BALB/c)F1 mice have been analyzed for the isoantigens they carry. NZB mice are genotypically Ig-1e Ig-3e, while BALB/c are Ig-1a Ig-3a. Two of the myeloma proteins are γG2a-globulins. One of these, GPC-7, carries all the isoantigenic specificities of the Ig-1e allele while the other, GPC-8, carries all the isoantigenic specificities of the Ig-1a allele. Thus only one of the parental alleles of the mouse in which the tumor arose is expressed in each of these myeloma proteins. The third myeloma protein GPC-5, also carries the antigens of only one parental strain (NZB). However GPC-5, a γG2b-globulin, carries only one of the Ig-3 specificities normally associated with γG2b-globulins of NZB. Most remarkably it also carries one Ig-1 specificity normally associated with γG2a-globulins of NZB. This is the first analyzed mouse myeloma shown (a) to express some but not all the antigenic specificities normally associated with an allele and (b) to carry antigenic specificities controlled by two distinct immunoglobulin loci. The implications of these findings are discussed in relation to the genetic control of immunoglobulins.


1976 ◽  
Vol 156 (3) ◽  
pp. 681-684 ◽  
Author(s):  
H Kaji

Investigation of biosynthesis of J chain in plasmacytomas induced in NZB mice revealed that this protein was not only synthesized in the cells that produce polymer immunoglobulin A but also in those that produce immunoglobulin G monomer. It was also found that protein similar to J chain of BALB/c-mice was associated with polymer immunoglobulin A but not with immunoglobulin G of NZB mouse myeloma proteins.


Lung Cancer ◽  
2015 ◽  
Vol 90 (1) ◽  
pp. 78-84 ◽  
Author(s):  
Shu Xia ◽  
Chiang-Ching Huang ◽  
Min Le ◽  
Rachel Dittmar ◽  
Meijun Du ◽  
...  

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Masayoshi Obatake ◽  
Koichi Sato ◽  
Shigehiko Yagi ◽  
Hiromi Ohtani ◽  
Katsumi Kito

Abstract Background Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated inflammatory disorder that can involve multiple organs. It is characterized by IgG4-positive plasma cell-rich storiform fibrosis and obliterative phlebitis associated with a high serum IgG4 level. There are few reports of gastric IgG4-RD, especially those detected prior to systemic or other organ involvement. Case presentation: A 70-year-old man was diagnosed with type 0–IIc gastric cancer at the anterior wall of the gastric corpus by upper gastrointestinal endoscopy. In addition, a submucosal tumor (SMT) 7 mm in diameter was found at the greater curvature of the angulus. Laparoscopic distal gastrectomy with regional lymph node dissection was performed. Pathology revealed a poorly differentiated adenocarcinoma in the type 0–IIc lesion and storiform fibrosis with infiltration of a large number of IgG4-positive plasma cells in the SMT. Postoperative laboratory testing showed elevation of serum IgG4 levels; thus, we diagnosed the SMT as IgG4-RD. Intriguingly, the gastric IgG4-RD lesion demonstrated IgG4-positive plasma cell-rich arteritis as well as typical obstructive phlebitis. The patient has been followed for 2 years after surgery without recurrence of cancer, but skin lesions of IgG4-RD have appeared. Conclusion We report a rare case of IgG4-RD presenting as a gastric SMT, accompanied by early-stage gastric cancer. Our case may support a newly proposed relationship between IgG4-RD and malignancies. The gastric IgG4-RD lesion showed arteritis as well as obliterative phlebitis, potentially providing novel insight into IgG4-related vascular lesions.


PLoS ONE ◽  
2016 ◽  
Vol 11 (8) ◽  
pp. e0160970 ◽  
Author(s):  
Iana H. Haralambieva ◽  
Michael T. Zimmermann ◽  
Inna G. Ovsyannikova ◽  
Diane E. Grill ◽  
Ann L. Oberg ◽  
...  

Biochemistry ◽  
1973 ◽  
Vol 12 (25) ◽  
pp. 5186-5194 ◽  
Author(s):  
Enrique Mendez ◽  
Blas Frangione ◽  
Edward C. Franklin

1986 ◽  
Vol 6 (11) ◽  
pp. 4031-4038
Author(s):  
M E Minie ◽  
M E Koshland

The gene for the immunoglobulin M (IgM)-polymerizing protein, the J chain, is activated when the mature B cell is triggered to secrete pentamer IgM. Activation of the gene was found to be associated with chromatin changes in a 240-base-pair region at the 5' end of the gene. Analyses of lymphoid lines showed that the 5' region was resistant to nuclease digestion at the immature B-cell stage; it became slightly more accessible in mature B cells and cells at an early stage in the IgM response and then displayed an open, hypersensitive structure in IgM-secreting cells. In addition, analyses of normal, mitogen-stimulated lymphocytes showed that the open hypersensitive structure was coinducible with J-chain gene expression. These results suggest that the 5' chromatin changes precede transcription, making control sequences within the site accessible to regulatory factors.


2020 ◽  
Author(s):  
Yuxin Wang ◽  
Guopeng Wang ◽  
Yaxin Li ◽  
Hao Shen ◽  
Huarui Chu ◽  
...  

AbstractSecretory Immunoglobulin A (SIgA) is the most abundant antibody at the mucosal surface. SIgA possesses two additional subunits besides IgA: the joining chain (J-chain) and secretory component (SC). SC is the ectodomain of the polymeric immunoglobulin receptor (pIgR), which functions to transport IgA to the mucosa. The underlying mechanism of how the J-chain and pIgR/SC facilitates the assembly and secretion of SIgA remains to be understood. During the infection of Streptococcus pneumoniae, a pneumococcal adhesin SpsA hijacks SIgA and unliganded pIgR/SC to evade host defense and gain entry to human cells. How SpsA specifically targets SIgA and pIgR/SC also remains unclear. Here we report a cryo-electron microscopy structure of the Fc region of human IgA1 (Fcα) in complex with J-chain and SC (Fcα-J-SC), which reveals the organization principle of SIgA. We also present the structure of Fcα-J-SC in complex with SpsA, which uncovers the specific interaction between SpsA and human pIgR/SC. These results advance the molecular understanding of SIgA and shed light on the pathogenesis of S. pneumoniae.


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