Naturally occurring leukaemia viruses in wild mice: how good a model for humans?

This article presents a historical perspective of the wild mouse leukaemia virus (MuLV) model system in light of the prevailing concepts in the early 1970s when this work was carried out. The epidemiology and natural history of MuLV and its associated lymphoma in wild mice were remarkably predictive of later events associated with human T-lymphotrophic virus infection and adult T-cell leukaemia in man. Striking similarities were noted in the exogenous mode of virus transmission, the regional and familial clustering of virus infection in association with specific lymphomas, the low pathogenicity and long latent period, the neurotropism, the virus stability and the nature of viral integration in resultant lymphomas. The wild mouse model was more accurate than the inbred mouse model in pointing the way to human disease. These results illustrate the importance of studying natural history in the 'real world' and the limitations of laboratory artefacts such as those created by inbreeding of laboratory mice.