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Researchers Identify Origins of Elusive HIV Strains, Shed Light on The Virus' Evolution

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The final two virus strains thought to have made the cross-species jump from simians to humans and ultimately developed into HIV-1 have finally been identified. In order to understand the significance of the discovery, it’s important to understand where these two particular strains fall within HIV’s larger virological family tree.

Eight of the most broadly recognized strains of HIV are classified as HIV-2 and are commonly coded A-H. These various strains each sprung from individual human exposures to different strains of SIV (simian immunodeficiency virus) found in the sooty mangabey. As Robbie Gonzalez points out for io9, while there are many different strains of HIV-2, the virus is not commonly observed outside of West African countries and is markedly less virulent than HIV-1.

HIV-1, on the other hand, is far more common globally due to higher virulence and a larger volume of different mutations. Some of the variants like CRF19, an M-class strain, have proven themselves to be markedly more effective at infecting individuals at an accelerated rate. Unlike HIV-2 strains the M and N classes of HIV-1 are thought to have originated from human to chimpanzee contact in areas where the animals are sometimes hunted for consumption. The origin of the O and P classes, however, had proven much more difficult to trace back.

According to a study covered in the most recent issue of Proceedings of the National Academy of Sciences, a team of researchers from the French University of Montpellier have positively identified a link between the O and P classes of HIV and a form of SIV found in gorillas.

“Two fully sequenced gorilla viruses from southwestern Cameroon were very closely related to, and likely represent the source population of, HIV-1 group P,” the study’s abstract explains. “Most of the genome of a third SIVgor strain, from central Cameroon, was very closely related to HIV-1 group O, again pointing to gorillas as the immediate source.”

Pinpointing the organisms in which these two variants of HIV originated, explains the study’s lead virologist Martine Peeters, has allowed her team to more wholly understand the ways in which different HIV strains have had such different evolutionary paths.

In an interview with The New York Times Peeters lays out her team’s theory that gorilla-sourced strains of HIV were met with more biological barriers to entry--making it less prevalent in the human population--purely by chance:

“So why did the chimpanzee S.I.V. lead to a worldwide epidemic, while S.I.V. from gorillas morphed into a human virus that remained in one small country?

Both viruses then adapted to their new hosts. The human immune system can stop viruses like H.I.V. with a protein called tetherin, which links newly made viruses to the cell in which they formed. The “tethered” viruses are unable to escape to infect a new cell.

In their new study, Dr. Peeters and her colleagues found that the chimpanzee and gorilla viruses evolved different strategies for attacking tetherin. But only one got an excellent opportunity to spread.”


9 Out Of 10 HIV Transmissions Occurring From People Not Receiving Care: VIDEO

HIV transmission

The tide of HIV transmission rates has been stemmed over the decades, but it hasn't stopped with estimated tens of thousands of new transmissions every year. A new CDC analysis is showing that of those transmissions, 91.5% of them are coming from people who have HIV and are not receiving treatment or care, including those who are not aware that they are infected. Said Jonathan Mermin, MD of the CDC:

We could prevent the vast majority of new infections tomorrow by improving the health of people living with HIV today.

Improving health includes:

[I]n addition to antiretroviral therapy, HIV care should include risk reduction counseling on how to protect their partners, screening and treatment for other sexually transmitted infections, and treatment for mental health and substance use disorders.

All ya gotta do is TUG: Take PrEP; Use a condom; Get tested. End HIV.

Watch a video from the CDC on how we can prevent the vast majority of new HIV infections, AFTER THE JUMP...

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Scientists Hope an AIDS Vaccine Hides in Llamas

Llama
(sklmsta - wikimedia commons)

BY SIMEON TEGEL / GlobalPost

The cute Andean animal’s antibodies are nearly 100 percent effective in stopping the deadly virus from spreading, researchers say.

LIMA, Peru — Fluffy, photogenic and super hardy at altitude, llamas have it all. They’re ideal for schlepping backpackers’ luggage over the high Andes or as a picturesque companion for that once-in-a-lifetime Machu Picchu selfie.

But now they may have an addition to their list of undoubted qualities: Llamas appear to be immune to AIDS and HIV.

The discovery, experts say, just might lead to a vaccine against the deadly virus or a treatment for those already infected. That’s according to new research by a team of experts from around the world, including University College London, Harvard Medical School and Argentina’s Center of Animal Virology.

CONTINUED, AFTER THE JUMP...

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AGGRESSIVE STRAIN OF HIV THAT CAUSES ACCELERATED AIDS DEVELOPMENT RESURFACES IN CUBA

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A number of Cuban patients have tested positive for a new, highly aggressive strain of HIV that seemingly develops into full blown AIDS much faster than most other strains. There is no set timeline for if and when an HIV-positive person will develop AIDS, it can take anywhere from 5 to 10 years according Anne-Mieke Vandamme, a molecular virologist who was contact by Cuban public health officials. These patients, Vandamme explained to Voice of America, were developing AIDS within 2 to 3 years.

"So this group of patients that progressed very fast, they were all recently infected," Vandamme explained to Voice of America. "And we know that because they had been HIV-negative tested one or a maximum two years before."

When we talk about HIV (a virus) and AIDS (a syndrome,) we tend to lump the two in together as a single ailment, and fail to differentiate between the multiple strains of HIV that function differently from one another.

AIDS, which is a persistent compromise of the immune system, typically develops in HIV-positive people who don’t have proper access to antiretroviral drugs that effectively stop the virus from being able to infect new cells. It can also result from a positive person merely having an already weak immune system.

Accoring to Vandamme, none of the six patients were being treated for HIV, but their immune systems were fully intact. The speed with which their AIDS progressed was linked to the very virus itself, a mutated variant that is being called CRF19.

"Here we had a variant of HIV that we found only in the group that was progressing fast. Not in the other two groups. We focused in on this variant [trying] to find out what was different. And we saw it was a recombinant of three different subtypes."

The new strain bears similarity to a number of Group M-class HIV strains that are found throughout Africa and Europe. This isn’t the first time that CRF19 has surfaced, Vandamme explained, but in the past it proved difficult to find people infected with that specific virus. Though the CRF19’s rising prevalence in Cuba is worrisome, it could also give researchers a better shot at understanding and treating the strain.


Scientists Discover Potent Agent That Could Lead To An HIV Vaccine

HIV and T-Cell

A drug candidate has been created by scientists at the Jupiter, Florida campus of The Scripps Research Institute that could pave the way for an HIV vaccine, Science Daily reports. In their studies, the drug candidate blocked every strain of HIV-1, HIV-2, and SIV that has been isolated from humans or rhesus macaques, including the hardest-to-stop variants. What's more is that the drug blocks much higher concentrations of the virus than would be encountered in normal human-to-human transmission and is effective for up to eight months after injection. In short, the way the vaccine would work is that it binds to two sites on the surface of the virus simultaneously, preventing entry of HIV into the host cell.

Said TSRI Research Associate Matthew Gardner, the first author of the study with Lisa M. Kattenhorn of Harvard Medical School:

When antibodies try to mimic the receptor, they touch a lot of other parts of the viral envelope that HIV can change with ease. We've developed a direct mimic of the receptors without providing many avenues that the virus can use to escape, so we catch every virus thus far.

(Photo credit: NIH)


Experimental Smartphone Peripheral Could Be The Future of HIV Screening

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A $34 smart phone dongle being developed by Columbia University could become the future of rapid HIV screening in clinics and the privacy of peoples’ homes. The proposed smartphone peripheral would operate similar to the way that most blood glucose testers currently function. Unlike most blood testers the testing dongle wouldn’t need its own power source, but would instead draw energy from a smartphone, tablet, or PC via a headphone jack. With a single drop of blood the device, detailed in Science Translational Medicine, would be able to effectively screen for HIV and two different types of syphilis antibodies.

The dongle is currently being tested in small trials in certain parts of Rwanda, and its early results have been promising, though flawed. Of the 96 patients participating in the technology’s limited trials, a number have been falsely identified as testing positive for antibodies that they didn’t have. Still though, further refinement and widespread deployment of future versions of the dongle could change the way that people participate in maintaining the public’s health.

Check out video of the dongle prototype AFTER THE JUMP...

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