title: Immunogenicity and protective efficacy of Brucella abortus recombinant protein cocktail (rOmp19+rP39) against B. abortus 544 and B. melitensis 16M infection in murine model.
abstract: In this study, the immunogenicity and protective efficacy of recombinant proteins Omp19 (rO) and P39 (rP) from Brucella abortus were evaluated individually and compared with the cocktail protein (rO+rP) against B. abortus 544 and Brucella melitensis 16M infection in BALB/c mouse model. Intra-peritoneal (I.P.) immunization with rO+rP cocktail developed substantially higher antibody titers predominant with Th1 mediated isotypes (IgG2a/2b). Western blot analysis using anti-rO+rP antibodies showed specific reactivity with native Omp19 (19 kDa) and P39 (39 kDa) among whole cell proteins of B. abortus and B. melitensis. Splenocytes extracted from rO+rP immunized mice induced significantly (P<0.001) higher proliferative responses at 30 μg/ml with considerable expression of pro-inflammatory cytokines (IFN-γ, IL-2 and IL-12) than rO and rP. Macrophage cell (RAW 264.7) monolayer supplemented with anti-rO+rP polysera exhibited enhanced viability against challenge with B. abortus 544 (72.27%) and B. melitensis 16M (68.57%). On the other hand, individual anti-rO and anti-rP polysera resulted in relatively lesser protection against the pathogens (64.79%, 54.45% and 47.13%, 45.11%, respectively). Immunized group of mice when I.P. challenged with 5 × 10(4) CFU of B. abortus 544 and B. melitensis 16M were found significantly (P<0.001) protected in the rO+rP group (log units of protection, spleen: 2.38, 2.12; liver: 1.04, 0.81, respectively) than in rO (spleen: 1.43, 1.21; liver: 0.7, 0.47) and rP (spleen: 1.24, 1.17; liver: 0.65, 0.34). Findings from this study depicted that rO+rP cocktail is highly immunogenic with the Th1 predominant serum antibody titers and T-cell mediated immune protection, would be a valuable intervention in the development of a safer and improved Brucella vaccine.
authors.affiliation: Department of Microbiology, Defence Food Research Laboratory, Siddarthanagar, Mysore, Karnataka, India. Electronic address: ganeshbabutmln@gmail.com.
authors.forename: Ganesh
authors.initials: G
authors.lastname: Tadepalli
authors.affiliation: Department of Microbiology, Defence Food Research Laboratory, Siddarthanagar, Mysore, Karnataka, India.
authors.forename: Amit Kumar
authors.initials: AK
authors.lastname: Singh
authors.affiliation: Department of Microbiology, Defence Food Research Laboratory, Siddarthanagar, Mysore, Karnataka, India.
authors.forename: Konduru
authors.initials: K
authors.lastname: Balakrishna
authors.affiliation: Department of Microbiology, Defence Food Research Laboratory, Siddarthanagar, Mysore, Karnataka, India.
authors.forename: Harishchandra Sripathy
authors.initials: HS
authors.lastname: Murali
authors.affiliation: Department of Microbiology, Defence Food Research Laboratory, Siddarthanagar, Mysore, Karnataka, India. Electronic address: drharshvardhanbatra@gmail.com.
authors.forename: Harsh Vardhan
authors.initials: HV
authors.lastname: Batra
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D015153:Blotting, Western; D002004:Brucella Vaccine / Q000276:immunology*; D002003:Brucella abortus; D017347:Brucella melitensis; D002006:Brucellosis / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D008074:Lipoproteins / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D033902:Periplasmic Binding Proteins / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology / Q000494:pharmacology; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002004:Brucella Vaccine; D008074:Lipoproteins; C097319:OMP19 protein, Brucella abortus; D033902:Periplasmic Binding Proteins; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic; C119927:p39 protein, Brucella
keywords: B. abortus; B. melitensis; Omp19; P39; Protein cocktail (rO+rP)