Diversity and antigenic potentials of Mycoplasmopsis bovis secreted and outer membrane proteins within a core genome of strains isolated from North American bison and cattle

Authors: Wynn, Emily; BROWNE, ANDREW - Animal And Plant Health Inspection Service (APHIS); Clawson, Michael - Mike

Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/24/2024
Publication Date: 3/4/2024
Citation: Wynn, E.L., Browne, A.S., Clawson, M.L. 2024. Diversity and antigenic potentials of Mycoplasmopsis bovis secreted and outer membrane proteins within a core genome of strains isolated from North American bison and cattle. Genome. https://doi.org/10.1139/gen-2023-0084.
DOI: https://doi.org/10.1139/gen-2023-0084

Interpretive Summary: Mycoplasma bovis is an economically important bacterial pathogen of cattle and bison. In cattle, it causes or contributes to the development of several different diseases including pneumonia. In bison, it causes a devastating pneumonia and polyarthritis with high death rates. M. bovis does not respond well to many antibiotics, making treatment of cattle and bison unpractical and uneconomical. An efficacious vaccine is needed that will protect both cattle and bison from M. bovis infections. When targeting microbial proteins for use in a vaccine, it is important to know the diversity of that protein at the population level, and its potential to elicit an immune reaction. To identify immunogenic targets for vaccine development, we analyzed the genomes of 381 M. bovis strains from cattle or bison in North America. Within the core genome, 65 genes were identified that encode proteins that are either located on the outer membrane of M. bovis or secreted, as both types of proteins are of interest for vaccine development. Each of the 65 proteins were characterized for the extent of their diversity within the 381 strains, and by the presence or absence of targets for cattle or bison immune systems. This information can be used without restriction as a reference in the selection or custom design of M. bovis antigens for development of an efficacious M. bovis vaccine.

Technical Abstract: Mycoplasmopsis bovis is a worldwide economically important pathogen of cattle that can cause or indirectly contribute to bovine respiratory disease. M. bovis is also a primary etiological agent of respiratory disease in bison with high mortality rates. A major challenge in the development of an efficacious M. bovis vaccine is the design of antigens that contain both MHC-1 and MHC-2 T-cell epitopes, and that account for population level diversity within the species. Publicly available genomes and sequence read archive libraries of 381 M. bovis strains isolated from cattle (n = 202) and bison (n = 179) in North America were used to identify a core genome of 575 genes, including 38 that encode either known or predicted secreted or outer membrane proteins. The antigenic potentials of the proteins were characterized by the presence and strength of their T-cell epitopes, and their protein variant diversity at the population-level. The proteins had surprisingly low diversity and varying predictive levels of T-cell antigenicity. These results provide a reference for the selection or design of antigens for vaccine testing against strains infecting North American cattle and bison.