M. Saito et al., MUTATION-RATES IN LTR OF HTLV-1 IN HAM TSP PATIENTS AND THE CARRIERS ARE SIMILARLY HIGH TO TAX/REX-CODING SEQUENCE/, Journal of neurovirology, 2(5), 1996, pp. 330-335
The genomic sequence of human T-cell leukemia virus type 1 (HTLV-1) is
highly conserved, although minor sequence variations enable classific
ation of the isolates into several subgroups. We previously reported,
however, that the Tax-coding sequence of HTLV-1 genome is highly varia
ble in a random fashion within individuals with HAM/TSP and asymptomat
ic carriers. Here, we describe frequent base substitutions in the LTR
sequence similarly to those in Tax-coding sequence. These observations
indicate that frequent mutations are not unique to the sequence encod
ing the most effective antigen for cytotoxic T lymphocytes, but also s
een in the LTR, a non-coding sequence. Thus, frequent mutations seem t
o occur during the viral replication process rather than the selection
of fare mutants by immune surveillance.