[Activity of lysosomal proteinases in the liver, spleen, thymus and peritoneal macrophages after immunization of mice with thymus-dependent and thymus-independent antigens].

Mice of the CBAxC97B/6 strain were immunized with sheep erythrocytes at a dose of 0.5 ml containing 5% and 25% of the cell suspension and with Vi-antigen at doses of 2 micrograms/ml and 10 micrograms/ml, respectively. Sheep erythrocytes caused dose-dependent stimulation of cathepsin B, C and H in spleen, whereas cathepsin B was activated 3.1-3.6-fold after administration of Vi-antigen. Functional state of the lysosomal proteolytic system did not alter in thymus in response to sheep erythrocytes, while Vi-antigen activated distinctly thiol-dependent proteinases. In peritoneal macrophages administration of sheep erythrocytes led to 2-5-fold decrease in activity of all the lysosomal proteinases studied (cathepsins A, B, C, D, H and L), however Vi-antigen exhibited direct dose-dependent effect on activity of cathepsins A, B, D and L. The data obtained suggest that T-independent reactions of the immune system were realized via thiol-dependent lysosomal proteinases.