|Maree, Francois -|
|Blignaut, B -|
|Esterhuysen, J -|
|DE Beer, T -|
|Theron, J -|
|O'Neill, H -|
Submitted to: Journal of General Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 15, 2011
Publication Date: June 22, 2011
Citation: Maree, F.F., Blignaut, B., Esterhuysen, J.J., De Beer, T., Theron, J., O'Neill, H.G., Rieder, A.E. 2011. Predicting antigenic sites on the foot-and-mouth disease virus capsid of the South African Territories (SAT) types using virus neutralization data. Journal of General Virology. 92(10):2297-2309. Interpretive Summary: We have investigated the genetic variation of the capsid-coding region of FMDV SAT1 and SAT2 strains in the sub-Saharan Africa during a 28 year period (1974 to 2002). In this study we have combined information of variability on virus capsid sequences (those containing the antigens responsible for the protective immune response), structural data and serological relatedness measurements to predict areas on the surface of the FMD virion that are antigenically significant. We were able to predict areas on the surface of the FMD virion that are relevant for antigenicity. These sites were mostly consistent with antigenic sites previously determined for types A, O and C using monoclonal antibodies and escape mutant studies. Our methodology offers a quick alternative to determine antigenic relevant sites for FMDV field strains. This work is relevant to the development of more effective FMD vaccines.
Technical Abstract: Foot-and-mouth disease virus (FMDV) outer capsid proteins 1B, 1C and 1D contribute to the virus serotype distribution and antigenic variants that exist within each of the seven serotypes. This study presents a phylogenetic, genetic and antigenic analysis of the South African Territories (SAT) serotypes prevalent in sub-Saharan Africa. Here we showed that the high levels of genetic diversity in the P1-coding region within the SAT serotypes are reflected in the antigenic properties of these viruses and therefore have implications for vaccine strain selection that would provide the best vaccine match against emerging viruses. Interestingly, although SAT1 and SAT2 viruses displayed a similar genetic variation within serotype (32 percent variable amino acids) antigenic disparity, as measured by r1-values, was less pronounced for SAT1 viruses (73 percent of r1 less than 0.2) compared to SAT2 viruses (17 percent of r1 less than 0.2) within our dataset, emphasising the high antigenic variation within the SAT2 serotype. Furthermore, we combined amino acid variation and the r1-values with crystallographic structural data and were able to predict areas on the surface of the FMD virion as antigenically relevant. These sites were mostly consistent with antigenic sites previously determined for types A, O and C using monoclonal antibodies and escape mutant studies. Our methodology offers a quick alternative to determine antigenic relevant sites for FMDV field strains.