Feline leukaemia virus: half a century since its discovery.

In the early 1960s, Professor William (Bill) F.H. Jarrett was presented with a time-space cluster of cats with lymphoma identified by a local veterinary practitioner, Harry Pfaff, and carried out experiments to find if the condition might be caused by a virus, similar to lymphomas noted previously in poultry and mice. In 1964, the transmission of lymphoma in cats and the presence of virus-like particles that resembled 'the virus of murine leukaemias' in the induced tumours were reported in Nature. These seminal studies initiated research on feline leukaemia virus (FeLV) and launched the field of feline retrovirology. This review article considers the way in which some of the key early observations made by Bill Jarrett and his coworkers have developed in subsequent years and discusses progress that has been made in the field since FeLV was first discovered.