Inhibition of HIV Replication by the Hairpin Ribozyme

Due to the increasing number of individuals with acquired immune deficiency syndrome (AIDS), considerable research efforts have focused on inhibiting replication of its causative agent, human immunodeficiency virus (HIV). Since the efforts of prophylactic vaccines have repeatedly failed, anti-viral strategies are now being aimed at direct inhibition of the virus or its replication. Infection by HIV leads to a progressive depletion of CD4+ cells of the immune system, resulting in the immunodeficiency associated with AIDS. HIV has proven a formidable therapeutic challenge for several reasons: (1) HIV permanently integrates its viral genome into the chromosomes of the host cell, (2) its primary targets are the cells of the body’s own defense system, namely, CD4+ T cells and macrophages, and (3) its genome is extremely plastic, undergoing high rates of mutation, thereby eluding the host’s immune system as well as potential vaccines and drug therapies.