[The role of the outer membrane proteins, determined by the Shigella flexneri invasiveness plasmid, in inducing cellular immune reactions].

Fractions of S.flexneri 2a 516 outer membrane proteins determined by plasmid pSF140 have been shown to possess immunomodulating activity and to be capable of influencing the intensity of hematopoiesis, manifested by the stimulation of endocolony formation, the increase of the amount of splenic colony-forming units in the marrow, the increase of the pool of proliferating splenic colony-forming units of the marrow and their intensive migration into the blood. Outer membrane proteins have been shown to produce an immunostimulating effect on the functional activity of effector B-lymphocytes shortly after their injection. On the contrary, S.flexneri 2a 516/4 pSF140- outer membrane proteins produce a less pronounced effect on hematopoietic stem cells and reproduce unspecific immunostimulating effect on the formation of B-cells, synthesizing antibodies to heterologous antigen.