Friday, October 18, 2019
HIV Research Paper Example | Topics and Well Written Essays - 1000 words - 1
HIV - Research Paper Example HIV has not had a cure yet. However, antiretroviral drugs are use to slow down the immune system cellsââ¬â¢ destruction. The discussion in this paper focuses on HIV phylogenetic classification and morphology, transmission and replication in the host, virulence and pathogeniciy factors, treatment, epidemiology and public control methods. Phylogenetic classification and morphology According to Fauci and Lane (n.d), HIV virion has a structure that is icosahedra. This virion contains external spikes. The spikes form from two main protein envelopes namely external gp120 and the transmembrane gp 41. On the surface of the infected cell, the viron buds form. These buds comprises of numerous host proteins. The main host proteins are Major Histocompartibility complex (MHC) class I and II antigens, which are incorporate into the hostââ¬â¢s lipid bilayer. The strains classified as HIV-1 fall into three distinct groups. These categories are M or Major, Outlier or O and N or New or non M/non O. Group M nearly responsible for global pandemic. Group M forms properly defined clusters on phylogenetic trees. M group subtypes are labeled A-D, F-H, J-K. Other relevant clusters are circulating recombinant forms or CRFs. These recombination events form because of divergent HIV strains within host individuals. Transmission and replication For all persons infected with HIV, there is a variable degree of viruses in genital secretions and blood. This is the case regardless of whether or not the patient has visible symptoms. The transmission of HIV virus occurs when infected blood or secretions are exposed to tissues of the eye, vigina, anal area, and mouth, broken skin such as cuts or needle punctures. The most common transmission modes are sexual contact, needles sharing and infected mothers to newborns during labor pregnancy or breastfeeding. HIV is an RNA virus. The main process associated with HIV RNA is reverse transcription of genomic RNA to DNA. This process is facilitated b y enzyme reverse transcriptase. Replication cycle starts when gp 120 protein binds with high affinity. Once gp120 binds to CD4, it undergoes a conformational change that facilitates binding to one of the co-receptor groups. After the envelope, protein binds to CD4 molecule fusion occurs with the host cell membrane through the exposed gp41 molecule. The virus then penetrates plasma membrane of target cell then coiling upon to combine both the virion and immune system cells (Lama and Planelles, 2007). Virulence and pathogenicity factors HIV buds through the cell membrane. The virus is characterized by a capacity to cause disease. One attribute of HIV is replication and transmission, toxic, adherence and attachment and aggressiveness. For the virus, attachment to host immune system cell membrane is essential for virulence. This provides the opportunity to combine with the cells and cause reduction in protecting the body from diseases. In order to persist in the host, HIV virus has to r eplicate making it contagious. As a result, the virus is infectious. In order to survive, it has to remain aggressive. Aggressiveness comes with the ability to invade, multiply and survive in the tissues of the host. This makes HIV resistance to host defense mechanism. This virus also has high toxicity, which makes it possible to invade as many cells as possible. As a result, host immune
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