Polymer IgM assembly and secretion in lymphoid and nonlymphoid cell lines: evidence that J chain is required for pentamer IgM synthesis.
AUTOR(ES)
Niles, M J
RESUMO
The requirements for IgM assembly and secretion were evaluated by introducing a constitutively expressed J-chain cDNA into lymphoid and nonlymphoid cell lines expressing the secretory form of monomer IgM. Assays of cell lysates and supernatants showed that only secretory monomer IgM is required for the synthesis and secretion of hexamer IgM, whereas J chain, as well as the secreted form of monomer, is required for the synthesis and secretion of pentamer IgM. Moreover, J chain facilitates the polymerization process so that pentamer IgM is preferentially synthesized. Other components of the polymerization process were found to be shared by all the cell lines examined, whether the cells were of lymphoid or nonlymphoid origin and had a rudimentary or developed secretory apparatus. These results identify monomer IgM and J chain as the two components that determine the B-cell-specific expression of IgM antibodies and, thus, as the appropriate targets for therapeutic regulation of IgM responses.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=42323Documentos Relacionados
- J chain synthesis and secretion of hexameric IgM is differentially regulated by lipopolysaccharide and interleukin 5.
- Assembly and secretion of pentameric IgM in a fusion between a nonsecreting B cell lymphoma and an IgG-secreting plasmacytoma.
- Polymeric immunoglobulin M is secreted by transfectants of non-lymphoid cells in the absence of immunoglobulin J chain.
- A selective defect in IgM antigen receptor synthesis and transport causes loss of cell surface IgM expression on tolerant B lymphocytes.
- Synthesis of IgM, IgG and IgA in rheumatoid arthritis.