Effects of normal and activated cell fractions on the growth of tubercle bacilli.

Fractions prepared from normal and activated liver cells were tested for the antimycobacterial activity by the agar plate diffusion test. Results showed that lysosome extracts of normal and activated cells exerted no antibacterial activity, cell extracts and lysosome membranes exerted some activity, and cell membranes exerted the strongest activity. The active materials of activated cells exerted stronger antituberculous activity than the corresponding materials of normal cells. Degrees of the antimycobacterial activity of various cell fractions showed a close correlation with the amounts of nonesterified fatty acids. This correlation, as well as other data, suggested that the antimycobacterial activity of cell fractions was caused by toxic fatty acids which were produced during the hydrolysis of lipoporteins or phospholipids by the activity of tissue lipases. The relationship of these findings to the mechanism of cellular immunity is discussed.