期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1973
卷号：70
期号：2
页码：416-420
DOI：10.1073/pnas.70.2.416
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Stimulation of bone-marrow-derived lymphocytes by locally concentrated concanavalin A involves first an increased intracellular synthesis of total protein and of immunoglobulin M at 10-14 hr, followed by the initiation of secretion of protein and of IgM at 24-30 hr after stimulation. Differentiation into immunoglobulin-producing and -secreting cells after stimulation is manifested by (a) a rate of IgM synthesis that increases continuously over total protein synthesis, and (b) an increased rate of IgM secretion with concomitant decrease of secretion of other proteins. Within stimulated bone-marrow-derived cells, IgM molecules were found mainly in their 7S form, together with some light-{micro}-heavy-chain precursors. Small amounts of polymerized 19S IgM are found associated with the cells. Only fully assembled 19S IgM was found secreted into the extracellular medium. Polymerization into the pentamer therefore takes place shortly before, or simultaneously with, secretion. Intracellular 7S IgM contains only glucosamine and mannose residues, with traces of fucose and galactose residues. Secreted 19S IgM has the full complement of carbohydrates with glucosamine, mannose, fucose, galactose, and N-glycolylneuraminic acid residues. During polymerization and secretion from the cells, IgM molecules therefore acquire all of the semiterminal and terminal residues of their carbohydrate groups.
关键词：mitogens ; differentiation of lymphocytes ; lymphocyte stimulation ; polymerization of IgM ; carbohydrate attachment to IgM
