BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: HIV (Page 2 of 2)

The True Origins of HIV

There’s no doubt you’ve heard of HIV, or Human Immunodeficiency Virus. The HIV virus, if left untreated can lead to AIDS, or Acquired Immunodeficiency Syndrome, which leads to progressive immune system failure (http://en.wikipedia.org/wiki/HIV#Discovery). HIV didn’t become a problem in the United States until the 1980s, but was around long before then. Alfred Roca, an assistant Professor at the University of Illinois believes HIV was around for much longer than we believe.

 

The Origins 

HIV was thought to be originated from SIV, or Simian Immunodeficiency Virus, that infected Chimpanzees in Central Africa. About ninety percent of humans infected with HIV are infected with a strain called HIV-1 Type M, which was believed to have crossed the species barrier anywhere between 1884 and 1924. However, believes that HIV crossed the species barrier many times before 1884, but was most prevalent in rural areas, so it remained undetected.

 

Why it was a mystery

If HIV was around long before we initially thought, why did it remain undetected. According to Roca, “the persistence of HIV in humans requires population densities typically of larger cities that appeared in West Central Africa during the colonial period.” HIV didn’t spread amongst humans pre-1884 because the population was not dense enough. In addition, diseases spread much faster. Many people would have died early from diseases such as smallpox, and those with compromised immune systems would have been hit first, thus the disease couldn’t spread.

Map of the prevalence of HIV in the world, according to the 2008 UNAIDS Preport

Roca also believes that different strains of HIV could affect people with different genes. Using data from The Human Genome Project, Roca was able to analyze the DNA of the Biaka people, who live in the forests where the chimpanzees responsible for our current HIV pandemic reside and 4 other African populations which live outside the chimpanzees’ range. Research done in the 1980s concluded there are 26 genomic locations that help resist HIV.

The results of the research were astounding. Roca and his team identified four genes that code for proteins that affect the ability of the HIV to affect the host or the progression of the disease. Several of these genes were common among the Biaka people. Though the results aren’t definitive, they show that natural selection does play a part in the transfer of HIV to human populations, which is why the disease didn’t thrive earlier.

 

 

Tricky Viruses

Photo Credit: Foto_di_Signorina Flickr

           Strong viruses, such as HIV, make the body work for them. Researchers in Copenhagen have been studying how these viruses manage to take over the body. The virus takes over one cell and then uses the RNA to influence the DNA, giving the virus complete control over the cell. The RNA of the virus is similar to the RNA of the cell. Therefore, the ribosomes of the cell copy the sequence from the virus instead of the actual RNA. This causes the cell to produce the virus’ proteins.

                The RNA of the virus has what is called a pseudoknot. Pseudoknots are places on the RNA that the ribosomes must decipher before it can move on. The pseudoknot holds the sequence for key destructive proteins of the virus and once the ribosome deciphers it, those proteins are produced. This is how HIV can spread so rapidly in the body and can take such a hold over the host; it doesn’t do any of the work.

Antibodies to the Rescue!

Photo Credit: RambergMediaImages Flickr

 

 

HIV is an extremely dangerous virus because our own antibodies cannot effectively attack it. HIV uses a coat of sugars to hide itself from our antibodies. Although the body cannot effectively fight HIV, it does its best by making new antibodies to try and attack this powerful virus. These new antibodies attach to different spots on the sugar coating of the virus. It uses the sugar coat to bind to a site on the virus where amino acids are exposed. Then the antibody attacks the virus from that site, disabling it.

 

The discovery of this antibody and the way it binds to the virus is important because it can lead to advances in a cure and a vaccine. It gave scientists key information about binding sites made out of sugars and amino acids. They can use this information, as well as information from other projects and discoveries to make a more effective vaccine. In fact, some recent tests have shown that the antibodies play an important role in the health of someone infected with HIV.

New HIV Prevention Technique

CC licensed by photo Micro World (flickr)

An exciting, cutting-edge approach to HIV prevention is quickly gaining support, as researchers  have been learning about special antibodies that have destroyed HIV in the lab.  Now, biologists at Caltech have taken the next step, as they have discovered a way to insert these antibodies into mice, thus protecting them from HIV infection.

This new approach to HIV prevention — called Vectored ImmunoProphylaxis, or VIP — is outlined in the November 30 advance online publication of the journal Nature.

This new technique in HIV prevention is revolutionary, as supposed to traditional methods that centered on developing a vaccine that would provoke the formation of antibodies or T cells in the body, VIP provides protective antibodies directly.

Mice treated with VIP have been shown to produce high concentrations of the protective antibodies throughout their lives, and remain protected from HIV when it is administered intravenously.

Still, researchers must make the next step and show that the antibodies produced from VIP work to destroy HIV in humans.  According to researchers however, the problem will not be whether the antibodies work, as they are relatively sure of its effectiveness.  Rather, experiments will have to be conducted to see if VIP produces enough of these antibodies.  According to Alejandro Balazs, lead author of the study and a postdoctoral scholar, “In typical vaccine studies, those inoculated usually mount an immune response — you just don’t know if it’s going to work to fight the virus.  In this case, because we already know that the antibodies work, my opinion is that if we can induce production of sufficient antibody in people, then the odds that VIP will be successful are actually pretty high.”

For more information on this revolutionary new technique, visit the page http://intelwars.com/2011/11/30/gene-therapy-turns-muscles-into-hiv-antibody-factories/ 

What do you think?  Will the VIP method be successful in humans, and will HIV and AIDS finally be conquered?

 

 

 

 

 

 

 

 

 

Can timing change everything?

A Map of Cambodia: Cambodia Map from CIA World Factbook

Amongst individuals living with HIV, twenty to thirty percent die because of an additional tuberculosis infection. This co-infection is extremely common in Cambodia, a nation with 63,000 out of 13.2-million individuals living with just the HIV diagnosis, which eventually leads to AIDS. The HIV/Tuberculosis co-infection makes up 6.4% of Cambodia’s 5% HIV diagnosed population.

Dr. Anne Goldfeld, who has done studies on this trial as a Harvard Medical School employee and as President of the co- founder of the Cambodian Health Committee, says,


“Tuberculosis claims the lives of more than half a million people with HIV worldwide every year…”

 

She also says,


“This is a tragedy, because TB is completely curable when diagnosed and treated properly even in a patient with advanced HIV, especially if the patient also receives anti-retroviral therapy.”

 

In the past, the treatment for the co-infection has been very consistent. The treatment for Tuberculosis has been given to a patient immediately upon diagnosis. Two months later, anti-retroviral (ART) therapy for HIV would be given. However, recently, a trial entitled CAMELIA , >Cambodian Early versus Late Introduction of Antiretroviral Drugs, has helped give hope to HIV patients. The trial, which was created by Cambodian, French, and

 

American doctors, began in 2006 and lasted until 2010, encouraged five Cambodian hospitals to give HIV treatment to co-infected diagnosed patients only two short weeks following anti-tuberculosis treatment. The five hospitals are Calmette Hospital, Khmero-Soviet Friendship Hospital, and three provincial hospitals in the Siem Reap, Svay Rieng, and Takeo regions. This trial cut down the waiting time for HIV treatment by six weeks and overtime, the trial increased the survival rate of co-infected individuals by 33%.  Could six weeks really change the chance of survival for tuberculosis and HIV co-infected patients by such a great percentage? The answer is: absolutely! Did all medical physicians involved in this field of medicine agree with these techniques used to aid co-infected individuals? The answer is: definitely not.

 

Many of those who were opposed to the trial’s process said that the two treatments of Tuberculosis and the HIV  would wear the body down if done at similar times. Additional difficulties could be created for the body, which could already face toxicity with the required seven pills a day. The treatment was not risk-free either. It was possible that the immune system could become increasingly inflamed as it “rebound[ed] from HIV’s suppressive influence.” This trial was also available to patients who had an extremely strong immune system (given their diagnosis) at the time of treatment. Nevertheless, the benefits of the treatment have been much greater and more substantial than those doctors’ fears holding co-infected individuals from getting treated.

Doctors are still learning how the CAMELIA treatment can be improved and altered for the future. However, there has been enormous success with moving the treatments of co – infected Tuberculosis and HIV patients closer by six weeks. In just Cambodia, 661 patients participated in the CAMELIA trial, and less than one percent of the population participating, missed an appointment of the 8,955 scheduled for the population at the five separate hospitals. Many doctors, Cambodian citizens, and observers wanted this trial to work, and it was happening! The World Health Organization (WHO) should be encouraging this treatment more! Thirty three more percent of the initially co-infected patients of Cambodia are living! So where will the trial go next to help co – infected Tuberculosis and HIV patients? Ethiopia.

Killing Two Birds with One Stone

Credit: Fillmore Photography Flickr

Can you imagine having TWO life threatening diseases? Well, for some in Cambodia, that is the case. HIV and TB are two very common diseases that plague Cambodia, as well as other countries. Typically, a patient would go through TB treatment for two months and then begin HIV treatment. However, a new study done by Dr. Anne Goldfeld, the Program in Cellular and Molecule Medicine at Children’s Hospital Boston, and the CAMELIA (Cambodian Early versus Late Introduction of Antiretrovirals) shows that people with HIV and TB can benefit by being introduced HIV Treatment two weeks, instead of two months, after TB treatment was started. 

Doctors and researchers used to believe that the two medicines too much for the body to handle. Combining these two treatments would include taking seven, yes seven, pills a day. In addition, the pills would actually work against each other, the TB pills would work up the immune system to attack the TB and the HIV pills would suppress the immune system to stop the HIV from getting worse. This would put a massive strain on the body. However, this new study shows that the combination of the treatments can actually benefit the patient.

As of now there is no specific research or answers as to why the combination of the TB treatment and the HIV treatment is so effective. However, the study’s results are definitive. The patients that started the HIV treatment two weeks after starting the TB treatment had a better survival rate than those that started the HIV treatment later, 33% greater, to be exact.

Although the study did not give the exact reason behind this beneficial combination, it opened the door to a multitude of possibilities for HIV and TB sufferers around the world.

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