Studies on the antigenic relationship between bovine subgroup 2 and conventional mammalian adenoviruses using immunofluorescence

In double immunodiffusion tests between a bovine subgroup 2 adenovirus (serotype 8) and other mammalian adenoviruses, no group-specific crossing was demonstrated. However, in cross-fluorescent antibody tests (FAT) between bovine subgroup 2 viruses (serotypes 5, 7 and 8) and conventional (non-subgroup 2) adenoviruses from several species (bovine adenovirus serotypes 1 and 2, ovine serotypes 1, 4 and 5, porcine serotype 1, and human serotypes 2 and 5) sharing of antigens was demonstrated. The FAT titres observed when rabbit antisera to conventional adenoviruses were used to stain bovine subgroup 2 viruses were, however, much lower than titres with other non-subgroup 2 viruses. The converse was also true. The crossing was also predominantly one-sided. The low level cross was confirmed using antisera to selected viruses prepared in chickens to exclude interference by possible natural adenovirus infections in the rabbits used to prepare the antisera in the initial experiments.