Assessment of immune protective capacities of the recombinant outer membrane protein q, iron superoxide dismutase and putative lipoprotein from bordetella pertussis

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2017
Yılmaz, Çiğdem
Pertussis is a contagious disease which is commonly seen among infants and children and caused by a human pathogen known as Bordetella pertussis. There are currently two vaccine types available against the disease; whole-cell (wP) and acellular pertussis (aP) vaccines. Due to the side effects of wP vaccine, aP vaccines are commonly preferred for vaccination. Despite high vaccination coverage, high incidence rates among adolescents and adults have been reported causing the resurgence of pertussis to be the focus of interest in many countries. Main reason is thought to be early waning immunity due to low efficiency of current aP vaccines. Thus, discovery of new antigens and development of new adjuvant systems are promising approaches to improve the efficacy of current aP vaccines. In the present study, protective capacities of recombinant outer membrane protein Q (OmpQ), putative lipoprotein (Lpp) and iron superoxide dismutase (FeSOD) proteins were evaluated in mice models infected with B. pertussis. The genes of interest from B. pertussis Tohama I were cloned and introduced into E. coli BL21(DE) cells. After purification, recombinant proteins were formulated with alum or monophospholipid A (MPLA) and intraperitoneally introduced to female BALB/c mice twice at intervals of three weeks. While spleens of mice were obtained for evaluation of antigen-specific IFN-γ levels, the lungs of mice were excised after bacterial challenge with B. pertussis Saadet strain to evaluate colonization. Sera were also collected to measure IgG1, IgG2a and IL-10 levels. All three recombinant proteins induced high level of antibody responses. While IgG2a-type response was slightly higher in MPLA formulations, Alum-adjuvanted formulations induced higher IgG1 production. Recombinant OmpQ and putative Lpp could not trigger antigen-specific IFN-γ and IL-10 production in both alum- and MPLA-adjuvanted formulations. FeSOD-MPLA vaccination resulted in production of higher level of IFN-γ and IL-10, while there was no significant increase induced by FeSOD-Alum. Moreover, only FeSOD-MPLA vaccination was able to reduce bacterial colonization in mice lungs. In view of these results, recombinant FeSOD adjuvanted with MPLA represents a promising formulation for development of new generation aP vaccines.
Citation Formats
Ç. Yılmaz, “Assessment of immune protective capacities of the recombinant outer membrane protein q, iron superoxide dismutase and putative lipoprotein from bordetella pertussis,” Ph.D. - Doctoral Program, Middle East Technical University, 2017.