title: Enzymatic modification of lymphocyte receptors for antigen. III. Resistance of receptors to trypsin at the peak of the immune response.
abstract: Using sheep erythrocytes (SRBC) as the antigen, two subpopulations of spleen antigen-binding lymphocytes could be distinguished by a marked difference in the susceptibility of their receptors to trypsin. In unimmunized animals, 30% of the antigen-binding cells were trypsin-resistant, whereas at 5 days after immunization, 80-90% were trypsin-resistant, indicating an increase of about 50-fold in trypsin-resistant antigen-binding cells per spleen. In contrast, trypsin-sensitive cells per spleen were only 4-fold higher on day 5 than before immunization. The rise in % trypsin sensitivity preceded the increase in rosettes per spleen, implying that immunization produced a preferential increase in trypsin-resistant antigen binding cells partly by converting sensitive cells to resistant cells. After the 5th day, the trypsin sensitivity of antigen-binding cells slowly returned toward the unimmunized level, but a booster injection of SRBC restored trypsin resistance. Trypsin resistance was not lost in the presence of sodium azide or protein synthesis inhibitors. But a slightly increased trypsin susceptibility was conferred by 2-deoxyglucose, implying that glycolysis or the glycosylation of protein may be involved in maintaining trypsin resistance.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000941:Antigens; D001665:Binding Sites; D004912:Erythrocytes / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice; D008808:Mice, Inbred CBA; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D013997:Time Factors; D014357:Trypsin
chemical_list: D000941:Antigens; D011947:Receptors, Antigen, B-Cell; D014357:Trypsin