[Detection of HTLV-1 provirus DNA in T-cell neoplasms]

Using polymerase chain reaction (PCR) amplification and Southern hybridization, gag, pol, env and pX region genes of HTLV-1 provirus were detected in T-cell malignancy such as adult T-cell leukemia/lymphoma (ATLL), mycosis fungoides in leukemic phase (MF) and, CD8-leukemia. The gag, pol, and/or env regions, were not amplified in some cases of ATLL, which was considered to be induced by mutation, but not deletion. However, the pX-1 and pX-2 regions could be amplified in all cases examined. As it is suggested that the pX gene plays an important role in leukemogenesis, the mutation may not occur in this region gene. Interestingly, the pX-2 was amplified in the cases with MF and CD8-leukemia as well. The amplified products were hybridized to the HTLV-1 pX sequence, even though the products contained DNA fragments with a size larger than expected as well as those of an expected size. These results indicated the possibility that the virus having sequence identical with HTLV-1 pX is integrated in the tumor cells of MF and CD8 leukemia.