The in Vitro Desensitization of Sensitive Cells by Trypsin

Peritoneal exudate cells from animals exhibiting delayed hypersensitivity are inhibited from migrating in vitro by specific antigen. This inhibition is completely abolished by pretreatment of the sensitive cells with trypsin. The action of trypsin is prevented by soybean trypsin inhibitor. The results of experiments with mixtures of normal and sensitive cells suggest that trypsin alters an immunologic capacity of the sensitive cells. Trypsinized sensitive cells are capable of passively transferring delayed hypersensitivity and peritoneal cells taken from recipient animals are inhibited from migrating in vitro by specific antigen. These results suggest that the cells rapidly resynthesize the material removed by trypsin. The possible nature of the material removed by trypsin is discussed.