Lysozyme inhibitors enhance immune response in mice

The effect of hen egg-white lysozyme (HEWL) inhibitors (such as heparin, histidine methylester, chitotriose, chitobiose) on immune response was evaluated by measuring antibody-producing cells and circulating antibodies in mice inoculated with these substances and the test antigen (SRBC or BSA). It was found that these compounds have an immuno-enhancing effect which is directly proportional to their inhibitory activity on HEWL. Conversely, HEWL inhibited the immunoenhancing effect of these compounds when injected together with these and the test antigen. The results suggest that one possible mechanism by which adjuvants stimulate immune response may be the inhibition of endogenous lysozyme.