Diversity and T-cell antigenic potentials of Mycoplasma mycoides subsp. mycoides vaccine candidates.

Mycoplasma mycoides subsp mycoides (Mmm) is the causative agent of contagious bovine pleuropneumonia (CBPP), a severe respiratory disease affecting cattle mostly in sub-Saharan African countries. CBPP can cause significant economic losses, and there is a need for efficacious vaccines to help bring the disease under control. To that end, all publicly available non-redundant whole genome sequences of Mmm strains isolated from cattle (n=15) were used to identify a 93% core genome of 806 genes, which included 86 of 208 genes encoding outer membrane and extracellular proteins identified from the literature. Many of them and their encoded protein products were found to be highly conserved at the sequence level, including at the sites of predicted epitope binding with bovine major histocompatibility complex (MHC) Class I and II molecules. Despite the high sequence conservation, multiple proteins had large differences in the numbers of MHC Class I and II epitopes and their predicted binding strengths. These results highlight several promising targets supporting the development of new recombinant protein vaccines for CBPP.