Stages of HIV replication and targets for therapeutic intervention.

The replication cycle of human immunodeficiency virus (HIV) is divided into an early and a late phase. Most of the steps of the cycle have been targeted in antiviral therapy, although the drugs currently available for clinical use are only effective against two replication enzymes of the virus, either against the reverse transcriptase or against the viral protease. The introduction of combination anti-retroviral therapy changed the prognosis of HIV infection. HIV-related morbidity and mortality rates in patients with advanced HIV infection have significantly declined. However, there are severe limits of HAART. Current anti-retroviral therapy do not allow viral eradication, therefore long-term use of the drugs is required. As a consequence, resistance develops in a significant portion of patients. Furthermore, several adverse metabolic side effects have been observed associated with the therapy. Therefore new approaches are required to control or eradicate this deadly virus infection.