A novel approach for an immunogen against Corynebacterium pseudotuberculosis infection: An Escherichia coli bacterin expressing phospholipase D.

Rodrigo Barros de Pinho, Mara Thais de Oliveira Silva, Gabriel Brenner, Mirna Samara Dié Alves, Vasco Azevedo, Ricardo Dias Portela, Sibele Borsuk

Microbial pathogenesis 2021 Feb

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Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis (CLA) in small ruminants. There is still needed an immunoprophylaxis model, which induces a protective and sustained immune response against the bacteria. In this study, we evaluated a recombinant Escherichia coli bacterin expressing the recombinant phospholipase D (rPLD) protein, the most relevant virulence factor of C. pseudotuberculosis, as a potential vaccine formulation. E. coli BL21 (DE3) Star strain was used for rPLD protein expression and was then inactivated by formaldehyde. Four groups with 10 Balb/c mice each were immunized twice within a 21 days interval: G1-control - 0.9% saline solution; G2- E. coli bacterin/pAE (naked plasmid); G3- E. coli bacterin/pAE/pld; G4-purified recombinant rPLD. Subsequently, the animals were challenged with a C. pseudotuberculosis virulent strain and evaluated for 40 days. The highest survival rate was observed for G3 with 40% protection, followed by 30% in the purified rPLD group (G4). These two groups also showed considerable IgG production when compared with the control group (G1). Also, a higher significant expression of interferon-γ was observed for the experimental groups G2, G3, and G4 when compared with a control group (G1) (p < 0.05). These results represent that a recombinant bacterin can be seen as a promising approach for vaccinal antigens against CLA, being possible to be used in association of different vaccine strategies. Copyright © 2021 Elsevier Ltd. All rights reserved.

Citation

Rodrigo Barros de Pinho, Mara Thais de Oliveira Silva, Gabriel Brenner, Mirna Samara Dié Alves, Vasco Azevedo, Ricardo Dias Portela, Sibele Borsuk. A novel approach for an immunogen against Corynebacterium pseudotuberculosis infection: An Escherichia coli bacterin expressing phospholipase D. Microbial pathogenesis. 2021 Feb;151:104746