Engineering Foot-and-Mouth Disease Viruses with Improved Growth Properties for Vaccine Development
Haixue Zheng, Jianhong Guo, Ye Jin, Fan Yang, Jijun He, Lv Lv, Kesan Zhang, Qiong Wu, Xiangtao Liu*,Xuepeng Cai
PLoS One.
doi: 10.1371
Abstract:
BACKGROUND:No licensed vaccine is currently available against serotype A foot-and-mouth disease (FMD) in China, despite the isolation of A/WH/CHA/09 in 2009, partly because this strain does not replicate well in baby hamster kidney (BHK) cells.
METHODOLOGY/PRINCIPAL FINDINGS:A novel plasmid-based reverse genetics system was used to construct a chimeric strain by replacing the P1 gene in the vaccine strain O/CHA/99 with that from the epidemic stain A/WH/CHA/09. The chimeric virus displayed growth kinetics similar to those of O/CHA/99 and was selected for use as a candidate vaccine strain after 12 passages in BHK cells. Cattle were vaccinated with the inactivated vaccine and humoral immune responses were induced in most of the animals on day 7. A challenge infection with A/WH/CHA/09 on day 28 indicated that the group given a 4-μg dose was fully protected and neither developed viremia nor seroconverted to a 3ABC antigen.
CONCLUSIONS/SIGNIFICANCE:Our data demonstrate that the chimeric virus not only propagates well in BHK cells and has excellent antigenic matching against serotype A FMD, but is also a potential marker vaccine to distinguish infection from vaccination. These results suggest that reverse genetics technology is a useful tool for engineering vaccines for the prevention and control of FMD.
