retrovirus – BioQuakes

How Do Ancient Viruses Still Impact Humans?

On October 20, 2022

When one thinks of the similarities between modern and ancient humans, one will probably think of the basic genetic material that determines our physical structure. However, what is not so obvious are the viruses that infected them yet remain in our genes. It is known that DNA containing these ancient viruses make up about eight percent of the human genome (Ancient Viruses). These viruses have previously been believed to be insignificant, however, recent research has disproved this theory.

The viruses that have been genetically passed down are known as retroviruses. Retroviruses spread by making copies of themselves through the production of RNA which contains instructions for its DNA and replication. This reproduction process, called transcription, is similar to that which is done in the nucleus of eukaryotic cells. However, in this case, the synthesized DNA is then placed in the DNA of the cell it occupies. With that in mind, For the genes containing these viruses (or any gene) to be activated, they must contain specialized RNA with the information for its reproduction and it must be revealed by a protein called the transcription factor.

Using data from the Genotype-Tissue and Expression project, scientists Aidan Burn, Farrah Roy, Michael Freeman, and John M. Coffin searched for these active virus genomes in healthy tissue. They specifically sought out HML-2 which is a relatively new virus. They also looked for the RNA which would indicate its activation. This virus was found in all of the tissue they examined and they found the highest activity of it in the cerebellum.

Though they were once harmful to humans, these viruses found within healthy cells and tissues no longer serve as functioning viruses. They are now known as Endogenous Retroviruses (ERV). They cannot infect, but rather they serve us in our immune system. Their activation has been shown to have a vital role in embryonic development and aid in the detection of cancer.

I found the origination of ERV in human genomes to be similar to that of mitochondria and chloroplasts’ origin in eukaryotic cells. It is likely that mitochondria and Chloroplasts were engulfed by bacteria cells and are now able to carry out their functions (reproduction) within them while also benefiting the cell (providing it with ATP). Similarly, at some point during human evolution, the virus entered humans and was then able to utilize its environment (the host cell) to reproduce. I would also describe the relationship between ERV and modern-day humans as symbiotic due to the recent research which has revealed their benefits.

Kid Cured from HIV

By arthenice

On March 12, 2013

In Student Post

For the first time an infant was cured from HIV virus as in, the child does not have “detectable levels of virus” and there are “no signs of disease without the antiretroviral therapy.” The child’s mother with diagnosed with HIV gave birth to her child that also had HIV which was confirmed when she was born. Doctors immedietly began a regiment of a “liquid antiretroviral treatment consisting of a combination of three anti-HIV drugs: zidovudine, lamivudine, and nevirapine.” This treatment was continued for 18 months. It is also noted that by day 29 the amount of infant’s viral load had fallen to less than 50 copies of HIV per milliliter of blood (copies/mL).

HIV is spread via blood, semen and vaginal fluids and breastmilk making children with HIV infected mothers extremely susceptible to the virus. HIV is a retrovirus meaning the virus does transcription in reverse, transcribing DNA from RNA. During infection, the HIV virus attaches to a compatible receptor on the host cell’s surface. The virus and injects its RNA and proteins into the host cell. The enzymes reverse transcriptase, integrase and protease are used to transcribe the virus from RNA to DNA and to integrate it into the host cell’s genome. The host cell then becomes a production house for the HIV virus producing the needed enzymes and genetic material to produce many more viruses. These newly formed viruses leave the cells in vesicles via exocytosis damaging the cell. This persistent damage to CD4 lymphocytes and the immune system eventually cases AIDS or acquired immunodeficiency syndrome. This diagnosis is determined through the person’s blood and their CD4 count.

18 months later the treatment was discontinued for unclear reasons.” After, blood samples were taken which revealed that there were undetectable HIV levels in the child’s blood. The child continues to thrive with no detectable levels of HIV in the the body without antiretroviral therapy. What doctors and scientists have taken from this case is that if antiretroviral therapy is started on “infants who are infected with HIV through their mothers via pregnancy or delivery” it may “prevent HIV from establishing a reservoir or a hiding place.” (http://www.biologynews.net/archives/2013/03/04/toddler_functionally_cured_of_hiv_infection_nihsupported_investigators_report.html)

Bees and HIV

By biosasha11

On March 10, 2013

In Student Post

By PaulSteinJC. Photo from Flickr. http://www.flickr.com/photos/kapkap/2632994523/

30 million people have died due to AIDS.

However, a cure is yet to be found.

HIV is a retrovirus that manages to evade detection from the immune system because the virus hides in latency, incorporated into your DNA.

Instead, doctors give patients a “drug cocktail” that slows the replication and action of HIV enzymes. However, this treatment does not stop the initial infection.

A recent study had found that nanoparticles carrying a toxin found in bee venom can destroy HIV.

Bee venom contains melittin, which can “poke holes in the protective envelope that surrounds HIV,” thereby destroying the virus.

The researchers believe that this discovery can help them develop a vaginal gel that may prevent the spread of HIV.

A researcher Joshua Hood hopes “that in places where HIV is running rampant, people could use this gel as a preventive measure to stop the initial infection.”

Hood also thinks that these nanoparticles could be used to treat existing HIV infections. The nanoparticles could be injected into the blood, clearing HIV from the blood stream.

This is truly a wonderful discovery. Hopefully, this is the first step towards ending the AIDS epidemic.

To read more about HIV visit these sites:

http://www.thesun.co.uk/sol/homepage/news/4831508/Bee-stings-could-prevent-the-spread-of-HIV-doctors-claim.html

http://www.plannedparenthood.org/health-topics/stds-hiv-safer-sex/hiv-aids-4264.htm

BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: retrovirus

How Do Ancient Viruses Still Impact Humans?

Kid Cured from HIV

Bees and HIV

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