TbpBY167A-Based Vaccine Can Protect Pigs against Glässer's Disease Triggered by Glaesserella parasuis SV7 Expressing TbpB Cluster I

Simone Ramos Prigol; Rafaela Klein; Somshukla Chaudhuri; Gabriela Paraboni Frandoloso; João Antônio Guizzo; César Bernardo Gutiérrez Martín; Anthony Bernard Schryvers; Luiz Carlos Kreutz; Rafael Frandoloso

doi:10.3390/pathogens11070766

TbpB^Y167A-Based Vaccine Can Protect Pigs against Glässer's Disease Triggered by Glaesserella parasuis SV7 Expressing TbpB Cluster I

Pathogens. 2022 Jul 4;11(7):766. doi: 10.3390/pathogens11070766.

Authors

Simone Ramos Prigol^{1

2}, Rafaela Klein¹, Somshukla Chaudhuri³, Gabriela Paraboni Frandoloso², João Antônio Guizzo², César Bernardo Gutiérrez Martín⁴, Anthony Bernard Schryvers³, Luiz Carlos Kreutz¹, Rafael Frandoloso¹

Affiliations

¹ Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo 99052-900, Rio Grande do Sul, Brazil.
² AFK Imunotech Ltd.a, Passo Fundo 99050-144, Rio Grande do Sul, Brazil.
³ Department of Microbiology and Infectious Diseases, Faculty of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
⁴ Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24007 Leon, Spain.

Abstract

Glaesserella parasuis is the etiological agent of Glässer's disease (GD), one of the most important diseases afflicting pigs in the nursery phase. We analyzed the genetic and immunological properties of the TbpB protein naturally expressed by 27 different clinical isolates of G. parasuis that were typed as serovar 7 and isolated from pigs suffering from GD. All the strains were classified as virulent by LS-PCR. The phylogenetic analyses demonstrated high similarity within the amino acid sequence of TbpB from 24 clinical strains all belonging to cluster III of TbpB, as does the protective antigen TbpB^Y167A. Three G. parasuis isolates expressed cluster I TbpBs, indicating antigenic diversity within the SV7 group of G. parasuis. The antigenic analysis demonstrated the presence of common epitopes on all variants of the TbpB protein, which could be recognized by an in vitro analysis using pig IgG induced by a TbpB^Y167A-based vaccine. The proof of concept of the complete cross-protection between clusters I and III was performed in SPF pigs immunized with the TbpB^Y167A-based vaccine (cluster III) and challenged with G. parasuis SV7, strains LM 360.18 (cluster I). Additionally, pigs immunized with a whole-cell inactivated vaccine based on G. parasuis SV5 (Nagasaki strain) did not survive the challenge performed with SV7 (strain 360.18), demonstrating the absence of cross-protection between these two serovars. Based on these results, we propose that a properly formulated TbpB^Y167A-based vaccine may elicit a protective antibody response against all strains of G. parasuis SV7, despite TbpB antigenic diversity, and this might be extrapolated to other serovars. This result highlights the promising use of the TbpB^Y167A antigen in a future commercial vaccine for GD prevention.

Keywords: Glaesserella parasuis; Glässer’s disease; TbpBY167A; cross-protection; serovar 7; vaccine.

Grants and funding

This research was funded by Secretaria de Desenvolvimento Econômico Ciência e Tecnologia do Rio Grande do Sul (SDECT, Grant 328–2500/14-0). S.R.P. was supported by Foundation of University of Passo Fundo Master fellowship. S.C. was supported by University of Calgary Eyes High Doctoral Recruitment Award.