[Identification of adult T-cell leukemia virus and its gene structure]

A human retrovirus ATLV (adult T-cell leukemia virus) was isolated from adult T-cell leukemia ATL and characterized. All ATL patients tested so far contained the provirus sequence in the leukemic cells and the site of the provirus integration indicated that the leukemic cells are monoclonal. However, in healthy carriers of ATLV, the proviruses are integrated at random sites. Molecularly cloned ATLV provirus DNA was sequenced from both terminal regions. The provirus was shown to contain two LTR sequences at each terminus of 8.7 kb viral genome and also contain proline tRNA binding site. These structural features indicate that the virus replicates by the same mechanisms as animal retro-viruses, but distinct from any group of the known animal retroviruses.