The Nature of Human Immunodeficiency Virus - Research Paper Example

Based on the previously stated statistics and information, there is every reason to worry about the AIDS epidemic. Most of the responsibility for controlling the spread of the virus rests upon the National Institutes of Health, the Centers for Disease Control and Prevention, and the governments of the world. Nevertheless, efforts to develop a cure for AIDS have proved to be fruitless. What is the main reason behind this and what is the missing link, that somehow makes medical experts and scientists keep losing the battle against AIDS and prevents them from developing a good treatment for it? An insight into the evolutionary origin of HIV provides answers to the questions about AIDS that have baffled everyone since the 1970s when the disease first broke out.

Structure
HIV usually infects the human host cell as an aggregate of virions or “roughly spherical particles” (Noble, n.d.). These particles, whose surfaces are studded with multiple spikes, are coated with a fatty material called the viral envelope, and it is this specific structure that facilitates the entry of the virion into the cell (Noble, n.d.).

HIV differs from other viruses in that its genes are made up of RNA, or ribonucleic acid, whereas other viruses have DNA, or deoxyribonucleic acid, in their genetic structure (Noble, 2010). The fact that it is RNA, and not DNA, that constitutes the main genetic material of HIV implies a relatively more complex process of replication compared to other viruses, as well as a natural tendency of HIV to engage in a rather continuous replication inside the host cell because of the “long terminal repeat” in RNA (Noble, n.d.).

Another characteristic feature of HIV is its simplicity of structure, which accounts for its “rapid rate of evolutionary change” (Rambaut et al., 2004). The fact that HIV is structurally simple and that it evolves rapidly means that it can readily develop resistance against any treatment and that it immediately develops a new lineage of resistant virions (Rambaut et al., 2004; “HIV: The Ultimate Evolver,” 2001). However, in order to fully understand how rapidly HIV evolves in the host cell, one needs to know how exactly the virus enters the cell.

Process of Entry into The Cell
According to CDC, HIV is transmitted through contact of the mucous membrane, damaged tissue, or blood with infected fluids, which can be any of the following: blood, semen, breast milk, vaginal secretions, body fluids that contain blood, as well as fluids that surround the brain, the spinal cord, bone joints and the unborn baby (“HIV Transmission,” 2010). As soon as HIV enters the bloodstream, a series of molecular and subcellular processes immediately ensue. HIV then, as it replicates in the cell, proceeds to destroy its host cell – the CD4+ T cells, which are white blood cells that maintain the human immune system (Noble, n.d.).

The first step of the entry of HIV into the human cells is through the virus attaching itself to the CD4 protein on the surface of the human cells. The spikes on the surface of the virus attach themselves to the protein and thereby cause the fusion of the viral envelope and the cell membrane of the host cell (Noble, n.d.). The contents of the virus are then released into the host cell. What follows is a three-step process: reverse transcription and integration, transcription and translation, and finally, further replication.