Evaluation and Influence of Bioenhancers on Antiretroviral Drugs

Abstract

Acquired immune deficiency syndrome (AIDS) is caused by a chronic infection with the newlinehuman immunodeficiency virus (HIV). HIV (Figure 1.1) belongs to a class of viruses called newlineretroviruses and a subgroup of retroviruses known as lentiviruses or slow viruses (Chiu et newlineal., 1985). The course of infection with these viruses is characterized by a long interval newlinebetween initial infection and the onset of serious symptoms. Following infection, HIV can newlinereplicate only inside cells, commandeering the cell s machinery to reproduce. Retroviruses newlinehave genes composed of ribonucleic acid (RNA) molecules whereas the genes of humans and newlinemost other organisms are made of a related molecule, deoxyribonucleic acid (DNA). newlineHowever, once inside the cell, HIV and other retroviruses use the enzyme reverse newlinetranscriptase to convert their RNA into DNA, which can be incorporated into the human newlinecell s genes (Smith et al., 2006). The first step in viral replication (Figure 1.2) is the newlineattachment of a viral particle to the CD4+ receptor and a coreceptor of the host cell (Berger et newlineal., 1999). After the virus fuses with the host cell, the HIV virion enters the cell. Once bound, newlineone of several coreceptors is necessary for the process of fusion and for the viral particle to newlinedisgorge its contents, i.e., two copies of the viral RNA. Once inside the cytoplasm of the cell, newlineHIV reverse transcriptase converts the viral RNA into DNA, the nucleic acid form in which newlinethe cell carries its genes. A full-length copy of the DNA is made, and then degraded into a newlinesmaller functional piece (Smith et al., 2006, Zheng et al., 2005). The newly made HIV DNA newlinemoves to the cell s nucleus, where HIV integrase helps splice the viral DNA into the host s newlineDNA. This integrated form of the virus is termed provirus. Once the viral DNA has newlineintegrated into the host cell DNA, the cell, if activated, will go on to make viral proteins.