Decreased colony forming ability of human cells persistently infected with baboon endogenous virus. Brief report

Plating efficiency (PE), i.e. colony forming ability, of primary human embryonic lung fibroblasts persistently infected with baboon endogenous virus (BaEV) decreased to less than 10 per cent of that of the uninfected cells. A line of human amnion (FL) cells showed a 55 per cent reduction of PE after the establishment of BaEV carrier state. No decrease of PE did occur as a result of BaEV persistent infection in a rhabdomyosarcoma cell line (A204) and in fibroblasts derived from adult human skin. This characteristic reduction of PE in the infected primary embryonic fibroblasts was completely abolished by cultivation of the cells with conditioned medium from confluent either virus-infected or uninfected culture.