Effect of Brucellin Conjugated with Gold Nanoparticles on the Immune Response and Phagocytosis of Brucella

A conjugate of 15-nm gold nanoparticles with brucellin, a polysaccharide-protein complex isolated from the Brucella vaccine strain, was obtained. The obtained conjugate was used to vaccinate white mice. The drug was administered intraperitoneally three times with an interval of 7 days. After that, all animals were injected with a suspension of cells of the Brucella abortus 82 vaccine strain. Using a cell proliferative test, it was shown that in the group of animals immunized with a brucellin conjugate with gold nanoparticles, phagocytic cells and splenocytes had higher metabolic activity compared to the group immunized with the native antigen. Moreover, this trend was enhanced after the introduction of the vaccine strain. The highest antibody titer was observed in animals immunized with a brucellin conjugate with gold nanoparticles (1 : 2560 initially and 1 : 10240 after stimulation with the vaccine strain). It is important that during the opsonophagocytic reaction, the level of opsonizing antibodies was very high, which helped neutralize bacteria persisting in the animals.