Antigenic and immunogenic properties of a chimera of two immunodominant African swine fever virus proteins

A chimera of the two immunodominant African swine fever (ASF) virus protein s p54 and p30 was constructed by insertion of the gene CP204L into a Not I restriction site of E183L gene. The resulting chimeric protein p54/30, expr essed by a recombinant baculovirus in insect cells and in Trichoplusia ni l arvae, retained antigenic determinants present in both proteins and reacted in Western blot with a collection of sera from inapparent ASF virus carrie r pigs. Remarkably, pigs immunized with the chimeric protein developed neut ralizing antibodies and survived the challenge with a virulent African swin e fever virus, presenting a reduction of about two logs in maximum viremia titers with respect to control pigs. In conclusion, this study revealed tha t the constructed chimeric protein may have utility as a serological diagno stic reagent and for further immunological studies that may provide new ins ights on mechanisms of protective immunity to ASFV.