title: Pretreatment of murine thymocytes by phytohemagglutinin inhibits the binding of H-concanavalin A.
abstract: The binding of H-concanavalin A (Con A) to cortisone-resistant and normal mouse thymocytes, which greatly differ in mitogenic responsiveness, was compared. Almost equal numbers of 3H-Con A molecules (7 x 10(5) molecules per cell) were found to bind to both cell types, and the rates of H-Con A binding were nearly identical. The binding capacity of thymocytes for H-Con A decreased rapidly after removal from the thymus and incubation in protein free synthetic medium. Similarly, mitogenic responsiveness droped rapidly after cells were exposed to this medium. H-Con A molecules bound to cells were dissociated from them after a brief incubation, about 30 percent of radioactivity being lost in 2 hr with increasing radioactivity being found in the supernatant. When cells were pretreated with PHA-P, which is a T cell mitogen, their mitogenic responsiveness to Con A was suppressed along with H-Con A binding to the cells. In contrast, a B cell mitrogen, LPS, that has a synergistic effect on the Con A mitogenic response in thymocytes had no effect on binding of H-Con A to thymocytes.
mesh_terms: D000812:Anhydrides; D001667:Binding, Competitive; D003208:Concanavalin A; D037102:Lectins; D008070:Lipopolysaccharides; D011135:Polysaccharides, Bacterial; D012486:Salmonella typhimurium; D013601:T-Lymphocytes / Q000276:immunology*; D013936:Thymidine / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology; D014316:Tritium
chemical_list: D000812:Anhydrides; D037102:Lectins; D008070:Lipopolysaccharides; D011135:Polysaccharides, Bacterial; D014316:Tritium; D003208:Concanavalin A; D013936:Thymidine