THE RELATIONSHIP BETWEEN IMMUNE RESPONSE AND HYDROLASE ACTIVITY IN RAT MONONUCLEAR LEUCOCYTES

Studies of differences in hydrolase activity of peritoneal mononuclear leucocytes from normal rats and rats given three injections of killed Francisella tularensis vaccine demonstrated increases of 37–69% in ribonuclease, deoxyribonuclease, and acid phosphatase in lysates of cells obtained from vaccinated animals. No deviation from normal was observed for B-glucuronidase, alkaline phosphatase, or cathepsin. Following a single injection of vaccine the activity of ribonuclease, deoxyribonuclease, and acid phosphatase decreased slightly and then increased, reaching a maximum of 96 h and returning to normal levels after 30 d. Stimulation of the animals with a second injection of vaccine at 96 h resulted in an immediate and pronounced depression in activity of deoxyribonuclease and acid phosphatase which also was followed by an increase similar to that observed initially. Analysis of the various leucocytic fractions revealed 52.2–56.4% of the total enzymatic activity to be associated with the cytoplasmic granules.