Inhibition of macrophage migration in Salmonella immunity.

Protein antigens were prepared from rough strains of Salmonella typhimurium and S. dublin by phenol and veronal-buffer extraction. It was shown that the in vitro migration of peritoneal exudate cells from guinea pigs that were immunized with rough avirulent mutants could be inhibited effectively with these antigens. The cells obtained from S. typhimurium-immunized guinea pigs were also sensitive to S. dublin antigens and vice versa. A degree of sensitivity and inhibition could be demonstrated consistently in a group of immunized guinea pigs. However, the variation in samples, even from among individual animals that had survived challenge, was so great that it precludes the use of the macrophage migration technique as a routine standard assay procedure for immunity.