Permissivity of lamb synovial membrane cell culture for Akabane disease virus

Presently, due to the variety and diversity of economic and tourist ties of Russia, episodes of accidental or maybe purposeful (i.e., biological terrorism) entry of exotic infectious pathogens including Akabane disease to the Russian Federation should not be excluded. Akabane disease is a viral transmissible infection. Its recurrent outbreaks are characterized by abortions, still or premature births, or malformations (e.g., arthrogryposis and/or hydrocephaly) for calves, lambs and kids. Akabane disease virus can persist both in animal body and in vitro (e.g., in continuous cell lines). A study of the sensitivity of African green monkey kidney cell line to Akabane virus carried out earlier showed that Akabane virus caused definite cytopathic changes resulting in cell rounding followed by cytolysis and detachment of the cell monolayer within 48 hours post infection. In this paper we first reported on the cytomorphological changes caused by Akabane virus in the primary lamb synovial membrane diploid cell culture (LSMCC) prepared according to an earlier developed procedure, and on a suitability of this culture for the virus accumulation in titers sufficient for study and making diagnosis. It has been formerly determined that the lamb synovial membrane cell culture is sensitive to small ruminant lentiviruses like caprine arthritis encephalitis virus or Visna-Maedi virus in sheep. LSMCC was prepared using a method for tissue explant culture. On day 4 post inoculation of the cell monolayer with Akabane virus the cytopathic effect appeared which manifested as formation of symplasts that grew larger due to their fusion on day 5 to 6. The Akabane virus activity was 6.0±0.05 lg TCID50/cm3 for strain V8935, and 5.0±0.05 lg TCID50/cm3 for strain P. As many as three passages and also the primary cell culture (after freezing) kept the virus-producing activity, and the Akabane virus retained its infective properties. The lamb synovial membrane cells can be re-cultured, and excessive diploid culture can be frozen to preserve and thawed as required. It is expedient to use a strain of diploid lamb synovial membrane cells deposited and patented earlier. One more advantage of the primary LSMCC as compared to monkey cell lines is that the latter ones may be a source of simian herpes B virus.