HIV/AIDS

HIV/AIDS

Introduction

HIV (human immunodeficiency virus) is capable to cause one of the most critical diseases in the world (AIDS). This virus deteriorates the defense mechanism inside the human body; making it vulnerable to every infectious virus that attacks the body. According to contrastive studies, the 100% cure of AIDS is not possible; however, the technological advancements and the augmentation in the scientific research have discovered the drugs that can suppress the infection cycle. These drugs suppress the progress of infected cells; hence, the life span of an individual suffering from HIV increases (Bowker et al., 2004).

In 1981 first situations of a new and mortal infection now renowned as came by immunodeficiency syndrome (AIDS) described in the CDC journal Morbidity and Mortality Weekly Report. Acquired immune deficiency syndrome was first identified in homosexual men, but it was shortly very resolute that the disease that determinants AIDS can disperse during sexual intercourse, body-fluid and body-fluid goods, and from mother to infant during pregnancy, consignment and breast feeding. AIDS initiated by the human immune deficiency virus (HIV).

The Cycle of Infection

There are two types of HIV HIV-1 and HIV-2. Both of the viruses are able to infect cells with their membrane on the receptor CD4. Each CD4 cell binds to another receptor in order to complete the cycle of infection. These are molecules belonging to the family of receptors representing seven trans-membrane domains coupled with G proteins. The HIV co-receptors contained in the virus mainly use CXCR4 (used by strains with tropism for lymphocytes T) and CCR5 (the strain with tropism for macrophages) to infect the cells of the victim. It is the gp120 protein that binds to viral receptors. The link with CD4 involves three non-contiguous regions; in addition, the link contains highly conserved gp120 membranes that separated from other areas (Gallo, 1991).

After the phase of contamination, the virus will initiate the process that causes the fusion between the viral membrane and the cells of the victim. In addition, the process causes conformational changes that triggered by CD4 binding through the loop of gp120 V3 and several cellular proteases. These modifications in the cell allow the insertion of the N-terminal sequence of gp41, consisting polar amino acids within the cell membrane. However, the merger does not occur without the binding of gp120 to its co-receptors. The gp120 are molecules belonging to the chemokine receptors (CCR5 and CXCR4) (Nye & Paskin, 1994).

CCR5 is the chemokine receptor used by ß- RANTES, MIP-a, MIP-ß, LD78-a, LD78-ß, and contains the natural ligand CXCR4 chemokine. The binding of the virus to the receptors allows the division of the strains of HIV R5 and X4. According to contrastive studies, HIV can productively infect the following cell types: lymphocytes, macrophages, microglia, and the dendritic cells (Bowker et al., 2004). The regulatory genes include the strains such as Tat, Rev and Nef. The process of synthesis occurs in the cytoplasm due to multiple splicing events; these events allow the amplification of gene transcription by the RNA polymerase type II cells and the stabilization ...