Comparative analysis of HTLV-I promoter activities reveals no disease-linked pattern of expression.

To investigate the possibility of an association between the type of pathology caused by HTLV-I and the activity of its promoter, we compared the levels of transcription obtained with six LTRs isolated from patients with two different HTLV-I-related diseases: ATL and TSP/HAM. The patients came from different geographical endemic areas. The LTR region was amplified by polymerase chain reaction (PCR) from the DNA of uncultured peripheral blood lymphocytes, and directly cloned upstream of the luciferase reporter gene. Constructs were tested by a transient transfection assay in a variety of cell lines. Although the activities of these LTRs were statistically different in some of the cell lines tested, no correlation could be demonstrated between the promoter activity and the nature of the disease. Thus, the data suggest that the LTR is not a major determinant of the nature of the disease associated with the infection by HTLV-I.