ABSTRACT
I. INTRODUCTION The acquired immunodeficiency syndrome (AIDS) was first recognized in 1981 when unusual clusters of Pneumocystis carinii and Kaposi’s sarcoma were reported in homosexual men in New York City, Los Angeles, and San Francisco and was further identified in every part of the world. The causative agents of AIDS were isolated 2 years later in France and in the United States (1-3) from the blood of patients and were later shown to be an enveloped RNA virus belonging to the lentivirus subfamily of retroviruses (4). By consensus these agents were named human immunodeficiency viruses (HIVs). AIDS is considered one of the most challenging pandemics of the end of this century, and the World Health Organization estimates that between 40 and 100 million individuals may be infected with HIV by year 2000 (5). HIV infection induces a progressive and severe immunodeficiency resulting in multiple infections by opportunistic bacteria, viruses, and parasites (6). Despite the development of antiretroviral drugs that improve the quality of life and the survival time of infected individuals, eradication of all virus-infected cells and cure of infection is not currently feasible and calls for novel therapeutic approaches, such as gene therapy.
