[Immunomodulating action of terrilytin].

When injected intramuscularly in a dose of 10, 20 and 40 proteolytic units terrilitin stimulates the immune response to sheep red blood cells (SRBC). Red cells of rats injected with terrilitin also stimulate the immune response to SRBC in intact syngeneic recipients. Splenocytes of rats injected with terrilitin secrete helper factor to the cultural medium. Supernatant of splenocytes incubated in the presence of red cells of rats injected with terrilitin possess more demonstrable immunostimulant properties than supernatant of splenocytes incubated with or without red cells of intact rats. Splenocytes of rats injected with red cells of rats pretreated with protease form the helper factor. Rat red blood cells treated with serum of animals given terrilitin are capable of inducing the production of the helper factor by splenocytes.