An Anti-Mycobacterial Principle of Peritoneal Mononuclear Cells

Abstract

The anti-mycobacterial substance found in guinea pig peritoneal mononuclear cells is heat labile. Heating at 56°C for 30 min at pH 6.3 destroyed its activity completely. It was found that peritoneal mononuclear cells contained approximately 0.2 × 10^-6 µg of lysozyme/cell. This observation, together with the facts that lysozyme is heat stable and that only relatively high concentrations of the enzyme inhibit virulent tubercle bacilli, led to the conclusion that the inhibitory material is distinct from lysozyme. The anti-mycobacterial activity was shown to be associated with the nuclear cell fraction. Nuclei of normal and immune cells inhibited tubercle bacilli to about the same degree. The activity of the nuclear fraction proved to be heat sensitive. The anti-mycobacterial activity of nuclear preparations was susceptible to a variety of hydrolases. Observations on the mode of action of the inhibitor suggest that it is bactericidal rather than bacteriostatic.