The distribution characterization of antibody-driven variations on viral capsid surface of FMDV serotype A between A/AF72 strain and A/GDMM/2013 strain.

A total of 135 A/AF72-neutralizaiton escape mutants were obtained by antibody pressure selection using 20 A/AF72-specific neutralization antibodies. The antibody-driven variations on A/AF72 strain were identified by sequence alignment of the 135 mutants and the frequency of varied amino acid residues at positions on VP3 (A), VP1 (B) and VP2 (C) were separately displayed. A total of 117 A/GDMM/2013-neutralizaiton escape mutants were obtained by antibody pressure selection using 19 A/GDMM/2013-specific neutralization antibodies. The antibody-driven variations on A/GDMM/2013 strain were identified by sequence alignment of the 117 mutants and the frequency of varied amino acid residues at positions on VP1 (D), VP2 (E) and VP3 (F) were separately displayed. (G) Footprint of key determinations on VP2 recognized by broad neutralization antibody (W125) and strain-specific mAbs (W121, R55, R95 and R127). The conserved determinations (_VP2T70, _VP2H77, _VP2Q196 and _VP3K61) recognized by W125 were circled with black dotted line and highlighted with pink. The surfaced determinations recognized by W121 (_VP271 and _VP272), R55 (_VP271, _VP279 and _VP282), R95 (_VP271, _VP272, _VP282 and _VP2131), and R127 (_VP272, _VP273, _VP274, _VP2130 and _VP2196) were all indicated in orange. (H) Footprint of key determinations on VP1 recognized by broad neutralization antibody W153 (_VP158) and strain-specific mAb W155 (_VP158, _VP1151 and _VP2143). The capsid proteins VP1, VP2 and VP3 on one protomer are colored blue, green and red, respectively.