The development of AIDS resulting from infection with the HIV-1 virus serves as a significant public health issue, killing 1.5 million worldwide yearly and infecting approximately 50,000 Americans per year. Approximately 35 million people worldwide are living with HIV/AIDS. This HIV virus is spread through different bodily fluids, usually ones that are traded during sex or while sharing needles. Most people will develop a flu-like illness within a month of being infected, followed by a lengthy period characterized by no symptoms. This virus is known for destroying the body’s immune system. When the immune system is sufficiently damaged, usually after 10 years, the infection progresses into AIDS. AIDS tends to be fatal because it severely weakens an individual’s immune system, making him/her much more likely to die from any infection, or to develop certain types of cancer.
When individuals are infected with this virus, the viral DNA becomes integrated into the human DNA. This DNA contains all the information that our cells need for proper development and maintenance of our health in the form of genes. Genes go through two processes: transcription and translation. When a given gene is transcribed, the DNA is used as a template to form an RNA molecule. RNA molecules are read by a structure within the cell known as the ribosome, which reads the RNA template and synthesizes a protein based on the code read. There is a great deal of regulation that occurs with this genetic code to ensure that the right genes are being expressed and the right proteins are being produced. However, viral DNA from the HIV-1 virus gets integrated into our genome. Since this viral DNA is made up of the same four-letter code as human DNA, it isn’t recognized as being “different.” Sometimes this viral DNA is expressed within the cells and sometimes it “lays low”, so to speak, leaving the individual with no symptoms. Viral DNA sequences remain in the human genome, waiting around until they are reactivated to wreak havoc within the human body by copying itself and spreading to infect other cells.
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The currently accepted treatment of HIV-1 infections is called highly active antiretroviral therapy (HAART). This treatment regimen uses various antiretroviral drugs to suppress different stages of the virus’ life cycle that occur when the virus is activated. However, this treatment is insufficient to eliminate low levels of viral DNA transcription or target cells that are latently infected with the HIV-1 virus. In Part 2 of this article series, we will discuss CRISPR/Cas, a new genome editing technology that may enable us to “edit out” HIV.
Feature Image Source: Lab Room by Heather Dowd