Thioredoxin Reductase Gene Expression and Activity among HTLV-1 infected Patients

Background: Human T-cell lymphotropic virus type 1 (HTLV-I) is the first human retrovirus, globally distributed and endemic in some areas such as northeastern Iran. Serious outcomes may be associated with this virus, including adult T-cell leukemia/lymphoma (ATLL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM-TSP). This study was designed to evaluate the relationship between virus-induced antioxidant imbalance and clinical state of HTLV-I infection. Material and Methods: Blood samples were collected from 40 HTLV-I patients consisted of chronic carriers and HAM-TSP patients and 40 healthy controls. A commercial kit was used to measure the enzyme activity, and real-time PCR was performed to measure TrxR gene expression in extracted peripheral blood mononuclear cells (PBMCs). Results: Mean ± SD of enzyme activity was as follows; HAM-TSP: 0.0928 ± 0.047, carriers: 0.134 ± 0.065, and controls: 0.1734 ± 0.056 μmol/min/ml, respectively). The fold difference of expression for carriers and HAM-TSP groups in comparison to healthy controls were 0.8 and 0.7 versus 1, respectively. Conclusion: Reduction in TrxR activity in HTLV-I infected individuals, particularly in HAM-TSP patients, was found. Cellular studies showed a reduction in TrxR gene expression, and the reduced TrxR activity during HTLV-I infection may contribute to virus-induced complications. The impaired activity of the Trx system may result in exacerbated infection-induced oxidative stress conditions.

Keywords:

Thioredoxin , HTLV-I , Real Time PCR