title: Alpha-macroglobulin-induced release of anti-Ig-coated particles from a subpopulation of rabbit B lymphocytes.
abstract: Approximately half of the rosettes formed by rabbit Ig+ lymphocytes (B cells) and anti-coated erythrocytes or glutaraldehyde-fixed bacteria are dissociated upon the addition of rabbit serum. Rabbit serum was fractionated and the rosette-dissociating activity was found in purified preparations of rabbit alpha 1- and alpha 2-macroglobulins. Studies designed to elucidate the mechanism of rosette dissociation suggested that the alpha-macroglobulins dissociated rosettes by causing the release or proteolytic cleavage of the membrane proteins complexed with the anti-Ig-coated particles. These data suggest that the alpha-macroglobulins may have a role in the interaction of B lymphocytes with particulate antigens.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D001769:Blood; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000276:immunology; D007122:Immunoelectrophoresis; D007136:Immunoglobulins / Q000276:immunology*; D011817:Rabbits; D012397:Rosette Formation; D000511:alpha-Macroglobulins / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D007136:Immunoglobulins; D000511:alpha-Macroglobulins