VIRAL GENE-PRODUCTS AND REPLICATION OF THE HUMAN IMMUNODEFICIENCY TYPE-1 VIRUS

The acquired immunodeficiency syndrome (AIDS) epidemic represents a mo dern-day plague that has not only resulted in a tragic loss of people from a wide spectrum of society but has reshaped our viewpoints regard ing health care, the treatment of infectious diseases, and social issu es regarding sexual behavior. There is little doubt now that the cause of the disease AIDS is a virus known as the human immunodeficiency vi rus (HIV). The HIV virus is a member of a large family of viruses term ed retroviruses, which have as a hallmark the capacity to convert thei r RNA genome into a DNA form that then undergoes a process of integrat ion into the host cell chromosome, followed by the expression of the v iral genome and translation of viral proteins in the infected cell. Th is review describes the organization of the HIV-1 viral genome, the ex pression of viral proteins, as well as the functions of the accessory viral proteins in HIV replication. The replication of the viral genome is divided into two phases, the early phase and the late phase. The e arly phase consists of the interaction of the virus with the cell surf ace receptor (CD4 molecule in most cases), the uncoating and conversio n of the viral RNA genome into a DNA form, and the integration into th e host cell chromosome. The late phase consists of the expression of t he viral proteins from the integrated viral genome, the translation of viral proteins, and the assembly and release of the virus. Points in the HIV-1 life cycle that are targets for therapeutic intervention are also discussed.