In the present study we examined in more detail the effects
of IFN treatment on induction of protective mechanisms
against FMDV. Groups of animals were inoculated with either
Ad5-CI-pIFN- or Ad5-CI-pIFN- alone or in combination,
challenged with FMDV 1 day later, and two animals from each
group were euthanized 1 day postinoculation (dpi) and 1 and 6
days postchallenge (dpc). We examined ISGs in skin, the main
site of virus replication, PBMCs, and lymphoid tissues and also
evaluated possible immune cell recruitment to the skin and
lymph nodes. We found that protection correlated with recruitment
of DCs and NK cells to the skin and lymph nodes,
respectively, and upregulation of a number of cytokines, some
of which have been shown to block FMDV replication in cell
culture (12), and chemokines that are involved in chemoattraction
of DCs and NK cells. The chemokine IP-10 was significantly
upregulated in all tissues examined, whereas MIP-3,and MCP-1 were mainly induced in the skin. These data suggest
that IFN-induced immunomodulatory, as well as antiviral,
activities may be involved in protection of swine against FMD.