Preparation of a cell line persistently infected with maedi/visna virus and production of viral antigens

SUZUKI, Kazuya; OGUMA, Keisuke; SENTSUI, Hiroshi

Retroviridae that mainly affects domestic sheep [11, 14] . Infected sheep develop fatal and progressive pneumonia and encephalomyelitis after a latent period of several months to years. Most MVVinfected sheep are asymptomatic but produce a specific antibody that persists for life [11, 13] . Therefore, effective and practical sero-diagnostic tests for identification of infected animals are needed for serological surveys. ELISA and agar gel immunodiffusion (AGID) tests have been used for the antibody survey [4] , and polymerase chain reaction (PCR) has been employed for pathogen detection [1] . SCP cells, which originate from the sheep brain choroid plexus (American Type Culture Collection [ATCC] No. CRL-1700), have been reported to be an MVV-sensitive cell line [15] but contaminated with bovine viral diarrhea virus (BVDV) [2] . MVV infection is recognized worldwide [16] , but the prevalence of the disease has been unknown in Japan. A recent serological survey revealed that there were seropositive sheep in Hokkaido and Iwate Prefectures according to a test for the MVV antigen [5] , and MVV was isolated from one of the seropositive sheep in Iwate Prefecture [12] . Using this isolate, we attempted to prepare a cell line that is persistently infected with MVV without contamination by other viruses and mycoplasmas.