ABSTRACT

They are two kinds of experimental strategies to study the pathologies associated with human T-cell leukaemia virus (HTLV-I). The first one is based on the analysis of the HTLV virus itself within different species: rabbits, mice, rats and monkeys have been used for this purpose. The other approach is based on the understanding of diseases induced by viruses closely related to HTLV-I, like bovine leukemia virus (BLV). Both viruses belong to the same subfamily of retroviruses, harbor a similar genomic organization, infect and transform cells of the hematopoietic system. The main advantage of the BLV system is that it allows direct experimentation in two different species, cattle and sheep. The goal of this review is to present the pathologies associated with BLV in these animals and to summarize the main conclusions which could be helpful to understand HTLV-I-induced leukemogenesis.