Characterization of a recombinant fowlpox virus expressing the native hexon of hemorrhagic enteritis virus

The structure of the icosahedral adenovirus capsid is highly conserved amon g Adenoviridae. In its native form, the hexon is the major capsid protein. The nascent hexon requires the 100 kDa folding protein to fold into its nat ive, trimeric form. The hexon and 100 kDa folding protein were co-expressed in a fowlpox virus (FPV) vector and in the recombinant FPVs (rFPVs) in whi ch the hexon and 100 kDa folding protein genes are cloned head to tail, the native hexon could be detected with indirect immunofluorescence and immuno precipitation using a native hexon monoclonal antibody. The FPV-@X100 const ruct, in which the 100 kDa folding protein gene follows the hexon gene in a head to tail fashion, elicited the best humoral response in chickens. An a ttenuated HEV commercial vaccine elicited higher and longer lasting anti-HE V titers than FPV-@X100. Humoral immunity was also compared in turkeys inoc ulated with rFPVs expressing the hexon alone, the 100 kDa folding protein a lone, or expressing both genes in different configurations. No anti-HEV hum oral immune response was detected in turkeys inoculated with the rFPVs expr essing the hexon alone or the 100 kDa folding protein alone.