[Study of enteric dysentery vaccines and their efficacy on a rabbit intestinal loop model. II. Changes in the mucosa of rabbit small intestine after oral immunization with live and chemical vaccines].

Ten days after oral immunization of 3 groups of rabbits with live vaccine prepared from the mixture of streptomycin-dependent mutants of Sh. flexneri 2a and Sh. sonnei, with Sh. flexneri and Sh. sonnei tryptic lysate, or with Boivin's extract of 6 Sh. flexneri and Sh. sonnei serotypes, a pronounced activation of the secretory and lysosomal apparatus was observed in ileac enterocytes. Deteriorating bacteria or their antigenic material was observed in ileac enterocytes. Deteriorating bacteria of their antigenic material was detected in phagolysosomas. An increased number of interepithelial lymphocytes, and mucous membrane lymphocytes (plasmoblasts and plasmocytes) was observed. The surface of the contact of lymphocytic cell membranes with enterocytes was also increased. It is suggested that special enterocytes with high pinocytic activity play an important role in the uptake and transport of antigenic material. The importance of the fact, previously unknown, that attenuated Shigella organisms are destroyed in enterocytic phagolysosomas is emphasized.