Farewell, but before we go…..

Welcome back to my very last blog post! Oh, how it saddens me how I won’t be able to write and educate about all the fun things I’ve learned about this human immunodeficiency virus!

It’s come so fast and over this quick period, I learned more than I thought I would’ve honestly. HIV has always been an interest of mine since my Infectious Disease class with Dr. Dix but with my visit to the CDC, diving deep into the how it infects us and more, I was able to gain a greater interest of it. I wanted to talk about an area that I didn’t cover and that was the history of HIV.

HIV was brought into light in the 1980’s in the US but is believed to be originated in the Democratic Republic of Congo in the 1920’s. When HIV first mentioned in the scientific world, it was only seen in gay men. The first cases of HIV in the US were in California where many gay men who had sexual contact would pass away from a separate disease due to the deficiency in their immune system. This illness became so common in the gay community and was only seen in gay men that in 1981, the illness was named gay-related immune deficiency (GRID). A year later, there were blood transfusion patients who contracted AIDS. This was a turning point because before this it was believed that this was only a sexually transmitted disease. Research in this field began to emerge to fully understand what type of disease this was, where it came from, how it can be transmitted, etc. As research emerged, new things were being discovered such as women can also contract AIDS through heterosexual sex and that HIV could be passed from mother to child through breast-feed. Research continued to find different ways of transmission but as time progressed, many researchers were interested in focusing less on the virus itself and more on vaccines and treatments.  The anti-retroviral drug AZT was approved and put on the market. The way this drug works is by stopping the pathway of reverse transcriptase, which is a very important component for HIV-infected cells to make new viruses. AZT would inhibit this enzyme and by doing so, these HIV-infected cells won’t reproduce as much virus throughout the body. This was a big deal at the time because to have a treatment that can slow down the reproduction of these infected cells because it aided in decreasing the chance of the patient’s symptoms worsening. As time progressed though, more drugs became familiar and a common treatment called triple combination therapy became very popular. This is where 3 different drugs would be taken together and worked together to fight against HIV and AIDS illness. I also wanted to mention the drug Truvada that we learned about in class and that I am actually familiar with from working in a pharmacy. I think this drug in particular is especially unique because instead of it being a treatment drug, it’s actually a prevention drug. Truvada is normally prescribed to those who at a higher risk of contracting HIV so by taking Truvada you would be completely inhibiting reverse transcriptase which will block the spread of HIV. This is all is an accomplishment in itself and HIV history and research has come such a long way, as you can see!

How does this virus work?

HIV goes through a cycle called the lytic cycle. The lytic cycle is a viral reproduction cycle that leads to the death of infected cells. There are multiple steps to this cycle starting with the entry/uncoating steps.

  1. Entry/uncoating: The HIV capsid fuses w/the CD4 cell membrane and the HIV genome and enzymes are exocytosed onto into the cell where they travel to the nucleus.

      2. Gene expression: HIV utilizes reverse transcriptase to convert HIV RNA into HIV DNA. This allows the host cell to accept integrate the HIV DNA into the cell. 

      3. Genome replication: The HIV DNA utilizes the machinery of the CD4 cells to create more copies of Viral HIV DNA via protein synthesize.

      4. Assembly: The Newly synthesized HIV nucleic acids (DNA/RNA) assemble into immature HIV.

       5. Egress: The immature HIV releases out of the host CD4 cell and releases protease. The protease enzyme breaks down the HIV proteins and they reform to become infectious HIV.

HIV does integrate its genome into the hosts by using reverse transcriptase to convert HIV RNA into HIV DNA, which integrates with the CD4 cells. HIV requires a host with DNA in order to replicate it’s genome. When HIV is present but not actively reproducing cells, these cells are considered to be a “latent HIV reservoir”. These HIV-infected cells, if are not reproducing, will go latent for as long as possible until it feels the need to be active. 

https://aidsinfo.nih.gov/understanding-hiv-aids/fact-sheets/19/93/what-is-a-latent-hiv-reservoir-

So what is HIV, you say??

Welcome back! Glad you decided to join me again in learning more about the fascinating life of the HIV virus! As we lasted talked in my blog post #1, I had the great pleasure of visiting the CDC for the first time and was able to find a microbe I was extremely interested in: the Human immunodeficiencyVirus also known as HIV which leads to AIDS. The CDC had a whole wall dedicated to AIDS, but I feel it is important to mention what leads to the it! HIV is a virus that harms a person’s immune system by attacking cells that are put in place to fight foreign

invaders like it. HIV is a virus that approximately 100 nanometers in diameter (https://en.wikipedia.org/wiki/Structure_and_genome_of_HIV) and comes in a cone-like shape (which is depicted below). Giving that this is a virus and viruses are acelluar (S/O to week 13 lecture on virus structure and replication for teaching that) This virus does have an enveloped so its considered an enveloped virus and the capsid structure is in a cone-like structure. HIV has 9 encoding genes that are unique to this virus, (https://en.wikipedia.org/wiki/Structure_and_genome_of_HIV) The way this virus works is by attaching to a host cell which is how they move through the body initially. HIV has a very interesting structure because it has both an envelope and a capsid protecting the RNA. But more importantly, in order for this virus to bind to human cells, it needs those receptors on the envelope. Some other important parts of the virus is proteins like protease, tat and reverse transcriptase that aid in allowing this virus to do it’s job efficiently.

 

Lastly, I learn best visually so I found a couple interesting videos that help me really put together what HIV is and does.

^This one was very monotoned and a bit dull but it helps carry the message home!

 

These are links where I found the pictures attached

http://(https://en.wikipedia.org/wiki/Structure_and_genome_of_HIV)