Aids Essay Research Paper IntroductionThe fate of — страница 3

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would include a weakened form of the virus. Doctors are reluctant to inject anyone with even a weakened form of the virus for the fear that it may cause an HIV infection. In works related to creating effective vaccines, scientists from NIAID have developed a vaccine with a suicide gene which allows itself to be killed off once its job is complete. Therefore the weakened HIV carries an extra gene taken from the herpes virus. Then the cells, which become infected with the HIV, can be selectively destroyed with a ganciclovir, which is a herpes medicine. The vaccine has only been tested in test tubes so far, but animal and human trials are being planned. Passive immunotherapy involves injecting late stage AIDS patients with the plasma of early HIV patients with the hopes that the

plasmas will boost the advanced patient s immune system and help fight off AIDS associated infections. (The Medical Advisor 1997, ps.97-99) The Virus and how it works Amazingly, although not good HIV is one of the most adaptable viruses ever found. It has been described by scientists as the stealth invader, elusive target, and a devious disguiser. The genetic makeup of the virus makes it virtually impossible to stop since it is constantly adapting to medicines and anti-viral drugs. And there are several different strands of HIV. A Retrovirus HIV is classified as an RNA or (ribonucleic acid) virus because it s genetic information is contained in RNA instead of DNA or (Deoxyribonucleic acid). The difference is that RNA is a single strand of genetic material that contains inherited

traits. Since it belongs to the retrovirus family, it has many features in common. Such as: h They have two single strands of RNA h They have a membrane-like outer cover also known as an envelope h They reproduce or replicate using the DNA of host cells h They hide themselves in the DNA of the host cell The task of the retrovirus is to convert their RNA to DNA. This conversion is called reverse transcription, or (retrotransmission). It is necessary to have Reverse Transcription for replication. This also allows the retrovirus use the protein making ability of it s host cell which it would not possess alone. Through the whole process of integration the viruses genetic information begins to look the same as that of the host cell. Making it undetectable by the immune system. The

first step involved for the virus to infect its host is to first make a DNA copy of their RNA. Then a second copy is made. Then this double strand of DNA is incorporated in the host cell s DNA. When the host cell replicates its genetic material in turn it also replicates the viral genetic material. Using this method the virus uses the host as a virus-making factory.(Packer 1998, pg. 34-5) That is why it is impossible to find a cure for HIV and AIDS because the viral information is implanted into the genetic information of the cells. In order to correct this there would have to be some kind of genetic manipulation involved, to remove the viral DNA without damaging the cells. For visual clarification of the viral producing factory see appendix 1.1 Structure of HIV HIV actually has

a very simple structure. It is a membrane of proteins that contain genetic material inside. The parts are shown in appendix 1.2 Each part not only has a name but there is a reference number to compare part to description. Envelope Protein: An outside covering, that serves as a protective membrane. This envelope has glycoprotein, (molecules of sugar and protein) that gives the virus its bumpy look. Each bump has two glycoproteins. One is a top protein (gp120), and the other is a stem like formation, a transmembrane glycoprotein (gp41) Inner Shell: An inner shell, or also know as matrix protein (p17), lies beneath the envelope and they are attached. Core: HIV has a core of capsid protein (p24). The core surrounds the genetic information and nucleic acid protein (p7). RNA: HIV s

genetic material is RNA. The RNA is present as two single strands that contain the genes with specific codes for the viral proteins, viral enzymes, and regulatory proteins of HIV. Enzymes: All retroviruses have three enzymes: reverse transcriptase, integrase, and protease. These are the enzymes that help with retroviral replication in the host cell. The reverse transcriptase helps in the building of a single strand of DNA that is a copy of HIV RNA. And also it destroys the original RNA molecule as the new DNA is made. See appendix 1.2 for diagram relating to parts of HIV virus. (Packer 1998, pg.35-7) for all listed definitions. Appendix 1.1 Viral Factory in Host Cell Appendix 1.2 The Parts of the AIDS Virus