title: Protective immunity induced by DNA-library immunization against an intracellular bacterial infection.
abstract: DNA-based immunization has shown to be a viable alternative approach to induce protective immunity against Brucella abortus infection. However, the use of a unique gene may not be sufficient to induce full protection. Therefore, a new strategy based on library immunization has been described to improve the level of protection against different pathogens and to identify new protective genes. In the present study, a B. abortus library was subcloned into the mammalian expression vector pCMV-Ubi. This plasmid was designed to create a fusion between the gene of interest with ubiquitin. The analysis of this Brucella-library showed approximately 72% of clones containing inserts with an average size of 500-2000 bp. Further, homology searches were performed using the BLASTn program, and all sequenced clones showed homology with Brucella genes, as expected. BALB/c mice immunised intramuscularly with the Brucella genomic expression library showed a strong specific total IgG antibody response to a Brucella protein extract, with production of IgG1 and IgG2a isotypes. Regarding cellular immunity, high levels of IFN-gamma and no IL-4 were detected in primed mouse splenocytes and partial protection against infection was reached in animals vaccinated with the Brucella library compared to the control group.
authors.affiliation: Department of Biochemistry and Immunology, Institute for Investigation in Immunology-Millenium Institute, Federal University of Minas Gerais, Pampulha, Belo Hoizonte-MG, Brazil.
authors.forename: Sophie Y
authors.initials: SY
authors.lastname: Leclercq
authors.forename: Sergio Costa
authors.initials: SC
authors.lastname: Oliveira
mesh_terms: D000818:Animals; D000917:Antibody Formation; D002003:Brucella abortus / Q000235:genetics / Q000276:immunology*; D002006:Brucellosis / Q000276:immunology / Q000517:prevention & control*; D005260:Female; D015723:Gene Library; D016680:Genome, Bacterial; D007111:Immunity, Cellular; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma; D015847:Interleukin-4 / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D014409:Tumor Necrosis Factor-alpha; D019444:Vaccines, DNA; D015847:Interleukin-4; D007371:Interferon-gamma