[The role of Shigella dysenteriae toxin formation at different stages in the forming of the cellular immune response in experimental animals].

The immunomodulating action of genetically related pairs of strains of S. dysenteriae 1, differing by the presence of high molecular plasmid with a mol. wt. of 140 mD and transposon-mediated mutation in the tox-gene chromosome (4 phenotypes: Inv+ Tox+; Inv+ Tox-; Inv- Tox+; Inv- Tox-), was studied. The study was carried out with the use of the experimental intraperitoneal infection of CBA mice with live Shigella cells in a dose of 5x10(7) microbial cells. For the first time the role of Shiga toxin synthesis at different stages of the formation of cell-mediated immune response was demonstrated in vivo. This response was manifested by the stimulation of hematopoiesis, pronounced sensitization of effectors of delayed hypersensitivity and an immunomodulating effect on immunocompetent B lymphocytes, synthesizing antibodies, specific to S. dysenteriae 1 LPS and non-specific to heterologous antigen (sheep red blood cells).