Delayed Hypersensitivity and Inhibition of Macrophage Spreading: In Vivo and in Vitro Studies of Tuberculin and Streptococcal Hypersensitivities in Guinea Pigs

Abstract

In Hartley guinea pigs sensitized with killed highly virulent group A type 24 Streptococcus pyogenes in Freund's complete adjuvant it was found that there was no marked difference in the cellular composition of peritoneal washings from normal and sensitized guinea pigs, and that macrophage spreading was inhibited in vitro by adding tuberculin and antigenic material from the streptococcus. In contrast, melitin or antigenic material from heterologous streptococci caused only slight inhibition of macrophage spreading. A very significant positive correlation was found between intensity of the cutaneous reaction and the degree of inhibition of macrophage spreading.