Multivalent Fusion DNA Vaccine againstBrucella abortus

Abstract

As an alternative brucellosis prevention method, we evaluated the immunogenicity induced by new multivalent DNA vaccines in BALB/c mice. We constructed the vaccines by fusion of BAB1_0273 and/or BAB1_0278 open reading frames (ORFs) from genomic island 3 (GI-3) and the Brucella abortus 2308 sodC gene with a link based on prolines and alanines (pV273-sod, pV278-sod, and pV273-278-sod, resp.). Results show that immunization with all tested multivalent DNA vaccines induced a specific humoral and cellular immune response. These novel multivalent vaccines significantly increased the production of IgM, IgG, and IgG2a antibodies as well as IFN-γ levels and the lymphoproliferative response of splenocytes. Although immunization with these multivalent vaccines induced a typical T-helper 1- (Th1-) dominated immune response, such immunogenicity conferred low protection levels in mice challenged with the B. abortus 2308 pathogenic strain. Our results demonstrated that the expression of BAB1_0273 and/or BABl_0278 antigens conjugated to SOD protein can polarize mice immunity to a Th1-type phenotype, conferring low levels of protection.

Intranasal Immunization of Mice with Multiepitope Chimeric Vaccine Candidate Based on Conserved Autotransporters SigA, Pic and Sap, Confers Protection against Shigella flexneri

“…Five mice per group were euthanized 30 days after the administration of the last immunization, and their spleens were removed under aseptic conditions. The spleens were used to prepare single-cell suspensions by mechanical disaggregation, and the erythrocytes were lysed using ammonium-chloride-potassium (ACK) buffer [ 32 ]. The cells were then washed with RPMI 1640 medium (Gibco TM , Life Technologies) and used to evaluate the lymphocyte proliferation in response to the chimeric multiepitope rMESF.…”

Evaluation of immune responses to Brucella vaccines in mouse models: A systematic review

“…The DNA vaccine encoding BAB1-0278 protects mice against B. abortus (40). DNA vaccines containing BAB1 0273 and/or BAB1 0278 and SOD C elicit immune responses in mice, but have low protective effect (41). DNA vaccines encoding p39 and/or groEL as well as other DNA-based vaccine candidates require several booster vaccinations while providing low levels of protection.…”

Bovine brucellosis – a comprehensive review

“…In this regard, immunization with multivalent DNA vaccines was done in BALB/c mice to assess the potential of immunogenicity. Multivalent DNA vaccines significantly induced high level of humoral immune response in terms of increased IgM, IgG, IgG2a, and enhanced cell-mediated immune response evidenced as high IFN- γ and lymphoproliferative response of splenocytes (Gomez et al 2017 ). In another experiment, genes encoding for numerous open reading frames (ORFs) were selected from genomic island 3 (GI-3) of B. abortus .…”