Brucellosis is a zoonotic disease caused by Brucella. In the Russian Federation, a live vaccine based on the attenuated strain B. abortus 19BA is used to prevent brucellosis in humans. However, pronounced reactogenicity and the likelihood of developing an infectious process after immunization make the creation of a safe subunit vaccine an urgent task. For this purpose, we created 47 recombinant brucellosis proteins and assessed their vaccine potential on a mouse cell culture.
THE AIM OF THE STUDY
Was to evaluate the immunogenic properties of recombinant Brucella proteins on cell culture and serum of BALB/c mice immunized with a Brucella vaccine strain.
MATERIALS AND METHODS
Using reverse vaccinology methods, candidate brucellosis proteins were identified, a technology for their production and purification was developed. 47 single and fused recombinant proteins were obtained in the E. coli system of optimal concentration and purity for their further use in immune assays. To assess the immunogenicity of recombinant proteins, BALB/c mice were immunized with the B. abortus 19BA vaccine strain, and on the 30th day of infection, the blood serum and spleens of the animals were collected. The proteins were used as specific inducers for stimulating lymphocytes in in vitro experiments and antigens for determining serum antibody titers in immune and intact mice. The levels of IFN-γ and IL-4 cytokines in lymphocyte cell supernatants, as well as serum specific antibody titers, were analyzed by enzyme immunoassay.
RESULTS
The ability of 47 recombinant brucellosis proteins to induce the formation of humoral and cellular immune responses was assessed. As a result, 41 proteins activating the synthesis of IFN-γ and 8 proteins to which IgG antibodies are formed were identified.
CONCLUSION
Brucellosis proteins capable of inducing a pronounced immune response in immunocompetent cells have been obtained and identified. These proteins can be considered as possible candidates for inclusion in vector, DNA and subunit vaccines against brucellosis in humans.
