DNA VACCINATION OF BISON TO BRUCELLAR ANTIGENS ELICITS ELEVATED ANTIBODY AND IFN-γ RESPONSES

Abstract

ABSTRACT:Brucella abortus remains a threat to the health and well-being of livestock in states bordering the Greater Yellowstone Area. During the past several years, cohabitation of infected wildlife with cattle has jeopardized the brucellosis-free status of Idaho, USA; Wyoming, USA; and Montana, USA. Current livestock B. abortus vaccines have not proven to be efficacious in bison (Bison bison) or elk (Cervus elaphus nelsoni). One problem with the lack of vaccine efficacy may stem from the failure to understand wildlife immune responses to vaccines. In an attempt to understand their immune responses, bison were vaccinated with eukaryotic DNA expression vectors encoding the Brucella periplasmic protein, bp26, and the chaperone protein, trigger factor (TF). These DNA vaccines have previously been shown to be protective against Brucella infection in mice. Bison were immunized intramuscularly at weeks 0, 2, and 4 with bp26 and TF DNA vaccines plus CpG adjuvant or empty vector (control) plus CpG. Blood samples were collected before vaccination and at 8, 10, and 12 wk after primary vaccination. The results showed that bison immunized with bp26 and TF DNA vaccines developed enhanced antibody, proliferative T cell, and interferon-gamma (IFN-c) responses upon in vitro restimulation with purified recombinant bp26 or TF antigens, unlike bison immunized with empty vector. Flow cytometric analysis revealed that the percentages of CD4 + and CD8 + T lymphocytes from the DNA-vaccinated groups were significantly greater than they were for those bison given empty vector. These data suggest that DNA vaccination of bison may elicit strong cellular immune responses and serve as an alternative for vaccination of bison for brucellosis.

Characterization of Periplasmic Protein BP26 Epitopes of Brucella melitensis Reacting with Murine Monoclonal and Sheep Antibodies

“…1 inducing not only high IgG1 titers but also cellular response of IFN-γ, IL-4, IL-5 and IL-6 [11]–[13]. In a separate study, we determined the IFN-γ response specific to T cell epitopes of BP26 in sheep ( data not shown ), which also indicated that BP26 was responsible for the mixed Th cell response.…”

“…The 62% (18/29) IgG1 of murine mAbs obtained in the present study, it suggested that BP26 might be associated with Th2 cytokine responses. Additionally the presence of BP26 enhanced antibody response to the chaperone protein, trigger factor (TF) [11]–[13], suggested that BP26 and other relevant proteins such as TF and omp31 might be involved in protective immunity to Brucella infections [25]–[28].…”

“…BP26 is highly conserved among B. abortus , B. suis , B. ovis , B. canis , B. neotomae and B. melitensis , and was sensitive and specific for diagnosis of Brucella infection in animals by enzyme immunoassays (EIAs) [6]–[10]. Excellent protective antigen and adjuvant activity were found with BP26 that induced elevated anibody and cellular responses [11]–[13]. However, the molecular feature of BP26 antigen remains unclear.…”

Progress in Brucella vaccine development

“…Using B. abortus soluble antigens combined with the adjuvant of dimethyldioctadecyl ammonium bromide to immunize steers, both humoral and cell-mediated immune responses were elicited (Dzata et al, 1991). Bison immunized intramuscularly with Bp26 and TF DNA vaccines produced enhanced antibody, proliferative T cell, and IFN-γ responses, indicating elicited cellular immune responses (Clapp et al, 2011b). Future studies are needed to assess the efficacy of this approach in livestock.…”

TUBERCULOSIS AND BRUCELLOSIS IN WOOD BISON (BISON BISON ATHABASCAE) IN NORTHERN CANADA: A RENEWED NEED TO DEVELOP OPTIONS FOR FUTURE MANAGEMENT

“…The reproductive cycle of female wood bison is well described, leading to techniques for successful embryo transfer and manipulation of the reproductive cycle to allow superovulation and artificial insemination (McCorkell 2008Adams et al 2010;Palomino et al 2010Palomino et al , 2011Palomino et al , 2012 (Lima et al 2003;Pan et al 2003;Nor and Musa 2004;Rhee et al 2004;Luo et al 2006a, b;Li et al 2008;Mir et al 2009;Silva et al 2009;Lee et al 2010), cattle, and bison (Clapp et al 2011). Combined bTB and brucellosis vaccines are more efficacious than either vaccine component alone in cattle (Hu et al 2009a(Hu et al , b, 2010.…”