Experimental infection of Mouflon-domestic sheep hybrids with caprine arthritis-encephalitis virus

Objective-To determine whether monocyte-derived macrophages from Mouflon-domestic sheep hybrids (Ovis musimon X Ovis spp) were susceptible to productive infection with caprine arthritis-encephalitis virus (CAEV) in vitro and whether experimental inoculation of Mouflon-domestic sheep hybrids with a molecularly cloned CAEV would result in persistent infection. Animals-5 Mouflon hybrids. Procedure-Macrophage monolayers were inoculated with virus in vitro. Three animals were inoculated with virus intratracheally. Results-Productive replication of CAEV was demonstrated in monocyte-derived macrophages following in vitro and in vivo inoculation. Titer of infectious cytopathic CAEV produced by macrophages from the Mouflon hybrids was similar to titers produced by macrophages from an infected goat or by synovial membrane cells. Isolation of virus from monocyte-derived macrophages and use of a semiquantitative polymerase chain reaction assay to amplify a portion of the viral genome demonstrated persistent virus replication in all 3 inoculated animals. Two weeks after inoculation of sheep, approximately 1 of 5,000 monocytes was harboring the virus. Conclusions and Clinical Relevance-Results indicate that Mouflon-domestic sheep hybrids are susceptible to infection with isolates of CAEV that cause infection in domestic small ruminants.