IMMUNIZATION WITH PROTEINS OF PSEUDOMONAS AERUGINOSA OprF AND aTox ENHANCES THE PHAGOCYTIC AND BACTERICIDAL ACTIVITY OF LEUKOCYTES IN MICE

Aim. To study the effect of vaccine preparation against Pseudomonas aeruginosa on the phagocytic and bactericidal activity of immunocompetent cells in mice. Materials and methods. Preparation: 25 pg of OprF, 50 pg of aTox sorbed by 75 pg of aluminum hydroxide. For immunization, the recombinant protein preparation was mixed in equal weight fractions with an aluminum hydroxide gel, diluted in phosphate buffered saline, and sorbed for 12 hours at 4°C. The vaccine preparation was administered intraperitoneally in 0.5 ml to BALB/с mice. The phagocytic activity of peripheral blood leukocytes was determined from the absorption capacity of heat-killed FITC-labeled Staphylococcus aureus by neutrophils and monocytes of immunized mice by flow cytometry. The bactericidal activity of mice blood leukocytes was assessed for the live culture of S.aureus using flow cytometry Cytomix FC-500 (Beckman Coulter). Results. Administration to mice of recombinant proteins P. aeruginosa OprF and aTox sorbed on aluminum hydroxide led to an increase in the phagocytic and bactericidal activity of monocytes and granulocytes of peripheral blood. The maximum increase in the number of phagocytized monocytes was observed on the 7th, and granulocytes on the 17th day after the first immunization. Booster immunization did not lead to additional stimulation of phagocytic activity, but the number of phagocytic cells was significantly (p<0.05) higher than control (intact mice). Conclusion. Candidate vaccine against P. aeruginosa based on its recombinant proteins OprF and aTox activates the cellular unit of the immune system with the induction of the activity of professional macrophages.