Transmission of bovine leukemia virus (BLV) to immunocompromised monkeys: evidence for persistent infection

Splenectomized or irradiated adult and untreated baby macacques were infected with bovine leukemia virus from continuously virus producing fetal lamb kidney cell cultures. Persisting high antibody titers were followed for 4 years in the adult and 16 months in the baby monkeys, using an ELISA technique. With the exception of a persistent leukocytosis in one adult monkey, the animals remained healthy throughout the observation period. Transfer of lymphocytes from this animal to a seronegative recipient led to anti-BLV seroconversion with a lag of 5 months. All other transfer experiments showed a negative result. Virus could be recovered from the newly infected baby macacques by means of lymphocyte/fetal lamb kidney cell cocultivation for up to 4 weeks after inoculation. All other attempts to recover virus from the infected animals at a later point were unsuccessful.