Aspects virologiques de l'infection par HTLV-1 et nouveaux concepts thérapeutiques Virological aspects of HTLV-1 infection and new therapeutical concepts

HTLV-1 was the first human oncogenic retrovirus to be discovered. It is the etiological agent of adult T leuke- mia/lymphoma (ATLL) and of tropical spastic paraparesis/ HTLV-1 associated myelopathy (TSP/HAM), two diseases that develop after a long latency period. Importantly, HTLV-1 does not cause ATLL through insertional mutage- nesis. Apart from the gag, pro, pol and env genes, which are common to all retroviruses, HTLV-1 genome also encodes regulatory and auxiliary viral proteins. Among the former, Tax promotes cell transformation and HBZ is involved in the leukemic cells proliferation and in the maintenance of the transformed phenotype. Anti-ATLL therapies have lately made significant progress with an efficient antiviral treatment against the chronic and smoldering forms of this leukemia, but an efficient treatment of TSP/HAM patients is still lacking. Results from a recent study asso- ciating histone acetylase inhibitor with an anti-viral drug will be discussed here. While an increase in proviral load is considered a marker for disease progression, this treat- ment allows a significant drop of the proviral load in asymptomatic carriers. To cite this journal: Bull. Soc. Pathol. Exot. □□□ (□□□□).