Phagocytic and bactericidal properties of macrophages of mice immunized with outer membrane proteins (OMP) of Shigella

Macrophages obtained from peritoneal exudates of mice immunized with the single doses (1 and 5 micrograms) of OMP were shown to have stronger phagocytic as well as bactericidal properties in relation to Shigella flexneri bacilli than nonactivated macrophages. Macrophages from the animals immunized with 10, 20 and 30 micrograms OMP doses showed phagocytic and bactericidal properties similar to those of nonactivated macrophages while the immunization with the dose 50 micrograms resulted in their suppression. Likewise, activity of macrophages from mice immunized twice or three times with various doses of OMP did not differ much from that obtained after immunization with single OMP doses. On the other hand, immunization of mice with a sublethal dose of live Shigella flexneri did not activate either phagocytic or bactericidal properties of macrophages. Besides, phagocytic and bactericidal activity of macrophages of mice immunized with OMP of Shigella was determined in relation to Salmonella typhimurium. The doses 1 and 5 micrograms of OMP resulted in slight activation of macrophages which manifested itself by a little increase in their phagocytic and bactericidal ability. When used in the dose 10 micrograms, OMP remained without any effect on the above activity of macrophages. Only the dose 50 micrograms, slightly suppressed their phagocytic properties.