SONAL GUPTA AND RAKESH BHATNAGAR
Molecular Biology and Genetic Engineering Lab, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India *(e-mail : rakeshbhatnagar@jnu.ac.in; Phone : +91 11 26704079)
(Received : March 19, 2019; Accepted : May 17, 2019)
ABSTRACT
Brucellosis is caused by Gram-negative bacteria of the genus Brucella, which infect different domestic and wild animals. So far, there is no available vaccine which is safe enough for administration. On this point, subunit recombinant vaccine has become the new breakthrough for combating brucellosis being protective and safe for administration. The main goals of the present study include determining the prophylactic potential of a divalent vaccine candidate consisting of BP26 and Omp25 against brucellosis. Merit of the BP26 periplasmic protein is that it is conserved throughout the Brucella genus. It induces a strong Th2 response with mild increase in IFN-gamma levels. Also, outer membrane protein 25 (Omp 25) is a highly conserved protein in Brucella sp. which is studied to be involved in virulence of Brucella. The current work involves studying the humoral immune response elicited by BP26+Omp25 vaccine candidate upon administration in mice. It was observed that divalent vaccine elicited antibodies against both its components and total IgG antibody response in divalent vaccine was comparable to the mice immunized with BP26 and Omp25 individually. IgG1 and IgG2a levels in mice were also studied to analyze Th1 and Th2 immune response in mice immunized with divalent protein combination. Altogether, the simultaneous immunization with two antigens complemented immune response against its individual components.
Key words : Divalent vaccine, BP26, Omp25, brucellosis