Search PubMed⌕ Search

Biomedical subjects

J Andersson

Publications and source records attributed to J Andersson.

At least 343 records · Page 19Linked to original sources
PubMed1973

The mitogenic effect of lipopolysaccharide on bone marrow-derived mouse lymphocytes. Lipid A as the mitogenic part of the molecule.

Lipopolysaccharides with different structure, isolated from different mutant strains of Escherichia coli and Salmonella bacteria, and chemical degradation products of these lipopolysaccharides have been employed to investigate which part of the lipopolysaccharide molecule exerts mitogenic effects on bone marrow-derived mouse lymphocytes. Within the structure of lipopolysaccharide consisting of lipid A, a core polysaccharide, and the O-polysaccharide antigen, lipid A was found to be the mitogenic part. The mitogenic effect of lipid A, consisting of phosphorylated glucosamine disaccharide units with ester- and amide-linked fatty acids, was lost after alkali treatment, which removes ester-linked fatty acids. Insertion of the lipid A portion of lipopolysaccharides into the lipid bilayer of the plasma membranes of bone marrow-derived lymphocytes is discussed as the initial mitogenic action.

Antibody Formation↗
PubMed1973

Induction of immunoglobulin M synthesis and secretion in bone-marrow-derived lymphocytes by locally concentrated concanavalin A.

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-mu-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.

Animals↗