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HIV: A Detailed Overview by Armin Begic

By at January 24, 2012 | 8:56 pm | Print

HIV: A Detailed Overview by Armin Begic

“The AIDS epidemic began over 25 years ago, and the disease continues to prey upon millions of children around the world. Over 2.1 million children are HIV-positive, with more than 400,000 children becoming newly infected with HIV / AIDS each year” (“Join Our Fight Against AIDS”). These statistics are just the ones among adolescents, so think about how much higher these numbers are within the rest of the population. There are two types of Human Immunodeficiency Viruses which affect people all over the world, HIV-1 and HIV-2. This essay only pertains to information about the HIV-1 virus, since it is the one that is most common in the world today and also because it differs from the HIV-2 virus. HIV victimizes a vast majority of the population around the world, but do people know the history of HIV, the science behind it, and the research in treatment?

As many people have heard, it is said that HIV has been around since the 1980’s, but that is totally false. HIV has actually been around since the 1880’s and there is much controversy and also many theories of how this virus appeared in humans. One theory is that many scientists know that immunodeficiency viruses existed among primates in Africa. Viruses such as SIV or Simian Immunodeficiency Virus were common among monkeys (“AIDS and HIV”). It is said that hunters in the late 19th century would hunt monkeys for their meat and most likely their fur as well. As the hunter killed the monkey, he would butcher the carcass. At times the butchering did not go as planned, and the hunter would cut himself accidently or the hunter would already have had cuts on his body. The blood of the infected monkey would come into contact with the hunter, and the hunter would have acquired the virus (McNeil Jr.). Now it has been stated that this virus did not present any serious effects on the human body, but over hundreds of years, this virus has mutated, and now scientists believe that this is the ancestor of HIV. Remember that this is only one theory out of thousands, but it seems very accurate. From the 19th century all the way up to the 1970’s this virus has been quiet, until it had entered the US. During this time the HIV virus had begun to slowly spread across the US and it was for the most part ignored by scientists. It took scientists another 10 to 15 years to come to the conclusion that this was a serious virus. Now in the year 2011 there have been new discoveries about the virus and how it works.

The science behind HIV is very intriguing considering the fact that this virus is still quite new to scientists and also that the majority of the people around the world have no idea how HIV works or any other virus at that. To start things off, HIV is a retrovirus that has been placed in a subgroup called lentiviruses. Lentiviruses are viruses which cause disease to an infected person or animal over a long period of time. As stated earlier, HIV is a retrovirus and this means a lot in identifying the science involved with this virus. Just about all organisms and most viruses store their genetic material on long strands of DNA, and this is where these retroviruses are different. Genes in viruses such as HIV and SIV, which are both retroviruses, are composed of RNA (“AIDS and HIV”). What this means is that these types of viruses convert RNA into DNA and then back to RNA for protein synthesis so they can live and multiply inside the host whereas most other viruses convert their DNA to RNA for protein synthesis. Being that HIV is an RNA based virus, means that its entire genome is encoded on one strand of RNA. This virus has two strands of RNA both of which are exactly identical. Unlike regular bacteria which consist of about 500 genes, HIV only has 9 (“AIDS and HIV”). These nine genes all have a certain job in HIV reproduction and infection. For this virus to be able to replicate, it has to be inside of human cells, which means that it cannot survive in or on any other object in the world. The way this virus infects a person is done through sexual, blood to blood, or needle sharing contact. The human body has a functioning immune system which has types of white blood cells called T cells. T cells are in charge of fighting off disease or harmful substances in the human body (Dugdale). These T cells have co-receptors which are glycoprotein’s called CD4. CD4 proteins are somewhat responsible for cell to cell interactions. Just like T cells, HIV has its own glycoprotein called the gp120. “The protein’s role is threefold: to seek receptors suitable for viral entry, to fix the viral particle to the cell, and to assist and direct the injection of viral material” (“Human”). Furthermore, the HIV cell also has a transmembrane called the gp41 attached to the gp120. The way an HIV cell is attached to a T cell is through a gp120 protein coming in contact with a CD4 protein. This attachment triggers this gp41 membrane to unfold, and attach to the T cells membrane pulling the virus cell membrane and fusing the two together. Once the virus is inside the helper cell is when the real process of damage starts to occur. A HIV enzyme named reverse transcriptase converts the RNA into DNA which is similar to the human genetic material. This DNA is then transferred to the cell’s nucleus where it is connected by another enzyme called integrase fusing the viruses’ genetic material to the human genetic material thus becoming a provirus (“AIDS and HIV”). What this means is that HIV is in there for life. The virus itself is part of your genetic material. With this virus encoded in the human DNA, it is very hard to become resistant at this point, although some people (about 1% of the world population) possess an immune gene where they just act as carriers. For everybody else, it is a much darker story from this point on. The provirus can be inside that single cell for weeks to months on end. At this point there really is not any damage occurring, but once a specific gene activates that cell, those virus genes are treated the same as regular human genes. Once the virus has been “activated”, some of the genes are converted into messenger RNA through the use of human enzymes. After this point, the messenger RNA travels outside the T cell’s nucleus and is used as a model for producing new HIV proteins and enzymes (“AIDS and HIV”). The finalization for the HIV virus is maturation. Newly made proteins and enzymes are combined with HIV genetic material carried on from the messenger RNA to create new viral particles, and these then are released from the cell. Some of these proteins are not the sufficient size required for the virus to reproduce so an enzyme called protease comes in and helps with this process. This enzyme simply just cuts up long strands of protein into smaller pieces (“AIDS and HIV”). The reason for this enzyme to cut up long strands of protein is simply for the functional needs of the virus. At this point, matured HIV particles go and attack other cells in the body and simply just repeat this whole process, easily killing off human helper cells, and also spreading quickly. With many of these helper cells being destroyed, the body is very vulnerable to diseases. Fortunately, scientists are working everyday in research for developing better treatment, and maybe even a cure.

The research for HIV treatment and cure has been going on for quite a while now. Each day scientists come up with better knowledge of how this virus works. In return, the more the scientists know about HIV, the better the knowledge they have on creating better treatment. The most recent discovery involves integrase inhibitors. Integrase is an enzyme found in HIV which lets genetic material of the virus combine with human DNA (“AIDS and HIV”). On the other hand, what these drugs known as integrase inhibitors do is quite simple. They block the genetic material of HIV to integrate with human DNA. According to a scientific journal about drug resistance, this medicine proved to be quite effective. After research was done, results showed that HIV replication was reduced. Although this drug proved to be a big step in helping with the fight against the virus, a big and more than likely problem emerged. After more research was performed, HIV showed some resistance towards this drug. HIV reproduces very fast, causing many mutations to occur which results in a higher chance of resistance. A group of doctors stated that this is a “remarkable advance” in treatment for HIV but other problems still exist. They went on to say that, these drugs did not completely stop the virus, and also that using these drugs for long periods of time lead to resistance from the virus. (Delelis, Marcelin, Mousecadet, and Tchertanov 139-150). Later on in their conclusion, this group of scientists went on to say that second generations of integrase inhibitor drugs were going to have a smaller chance of resistance. Taking a step away from drugs, some scientists have begun to explore people’s genes. It has been shown that a slight number of people are somewhat immune to the virus. These people are known as elite controllers. These elite controllers contain a gene which does not let the virus replicate and affect the person as it should. In a CBS article about a man who was cured of HIV, it is stated that this immunity gene dates back to the Great Plague, and the people who survived this plague could possibly have passed these genes to their heirs. This man who was cured of HIV was 45 years old. He is said to be the first person to be cured of HIV through this immunity gene. He was diagnosed with HIV in 1995 and in 2007 he was scheduled for a bone marrow transplant. Luckily he received stem cells from a donor who was immune to HIV. After this process was over, the man quit taking medication and was cured from HIV. Dr. Jay Levy, who co-discovered the HIV virus went on to say, “If you’re able to take the white cells from someone and manipulate them so they’re no longer infected, or infectable, no longer infectable by HIV, and those white cells become the whole immune system of that individual, you’ve got essentially a functional cure” (“Apparent Immunity Gene ‘Cures’ Bay Area Man of AIDS”). Now this was just one instance of a man being cured of the virus, and as of that point scientists are still working to try and find out the science behind this miracle. As crazy as it might seem, the cure for HIV might be located where we least expect it, the place where the virus thrives, right inside of the human body.

HIV affects millions upon millions of people each and every year. Most of these people are innocent kids, but they range from not only kids but to teenagers, middle aged people, and older people as well. HIV has been around for a long time dating all the way back to the 19th century. Worldwide outbreaks did not occur until the 20th century in which scientists first chose to ignore the virus. The reason to ignore the virus was more than likely due to ignorance, but now some of the public and most scientists know for the most part how the virus functions and they are working everyday to learn more about it. Using this knowledge scientists come closer each and every day to finding better treatment, and maybe even a cure. Who knows, maybe the key to taming this virus lies within our own blood.

 

Works Cited
“Aids and HIV Information.” Avert.org. Avert, 2011. Web. 16 Nov. 2011.
“Apparent Immunity Gene ‘Cures’ Bay Area Man of AIDS.” Sanfrancisco.cbslocal.com. CBS Local Media, 16 May 2011. Web. 16 Nov. 2011.
Delelis, Marcelin, Mousecadet, and Tchertanov. “Resistance to HIV-1 integrase inhibitors: A structural perspective.” Drug Resistance Updates 13 (August-October 2010): 139-150. Web. 16. Nov. 2011.
Dugdale, David. “T cell count.” Nlm.nih.gov. U.S. National Library of Medicine, 20 Aug. 2011. Web. 15 Nov. 2011.
“Human Immunodeficiency Virus Glycoprotein 120.” Bio.davidson.edu. Department of Biology, Davidson College, 22 May, 2005. Web. 16 Nov. 2011.
“Join Our Fight Against AIDS.” Unicef.org. United States Fund for Unicef, 2011. Web. 14 Nov. 2011.
McNeil Jr., Donald G. “Precursor to H.I.V. Was in Monkeys for Millenniums.” New York Times. The New York Times Company, 16 Sep. 2011. Web. 14 Nov. 2011.

 

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