7 replies to this topic

[LWFM]

Scientists find way to ‘disarm’ AIDS virus

September 19th, 2011

(Reuters) – Scientists have found a way to prevent HIV from damaging the immune system and say their discovery may offer a new approach to developing a vaccine against AIDS.
Researchers from the United States and Europe working in laboratories on the human immunodeficiency virus (HIV) found it is unable to damage the immune system if cholesterol is removed from the virus’s membrane.
“It’s like an army that has lost its weapons but still has flags, so another army can recognize it and attack it,” said Adriano Boasso of Imperial College London, who led the study.
The team now plans to investigate how to use this way of inactivating the virus and possibly develop it into a vaccine.
Usually when a person becomes infected with HIV, the body’s innate immune response puts up an immediate defense. But some researchers believe HIV causes the innate immune system to overreact. This weakens the immune system’s next line of defense, known as the adaptive immune response.
For this study — published on Monday in the journal Blood — Boasso’s team removed cholesterol from the membrane around the virus and found that this stopped HIV from triggering the innate immune response. This in turn led to a stronger adaptive response, orchestrated by a type of immune cells called T cells.
AIDS kills around 1.8 million people a year worldwide. An estimated 2.6 million people caught HIV in 2009, and 33.3 million people are living with the virus.
Major producers of current HIV drugs include Gilead Bristol Myers Squibb, Merck, Pfizer and GlaxoSmithKline.
Scientists from companies, non-profits and governments around the world have been trying for many years to make a vaccine against HIV but have so far had only limited success.
A 2009 study in Thailand involving 16,000 volunteers showed for the first time that a vaccine could prevent HIV infection in a small number of people, but since the efficacy was only around 30 percent researchers were forced back to the drawing board.
An American team working on an experimental HIV vaccine said in May that it helped monkeys with a form of the AIDS virus control the infection for more than a year, suggesting it may lead to a vaccine for people.
HIV is spread in many ways — during sex, on needles shared by drug users, in breast milk and in blood — so there is no single easy way to prevent infection. The virus also mutates quickly and can hide from the immune system, and attacks the very cells sent to battle it.
“HIV is very sneaky,” Boasso said in a statement. “It evades the host’s defenses by triggering overblown responses that damage the immune system. It’s like revving your car in first gear for too long — eventually the engine blows out.
He said this may be why developing a vaccine has proven so tricky. “Most vaccines prime the adaptive response to recognize the invader, but it’s hard for this to work if the virus triggers other mechanisms that weaken the adaptive response.”
HIV takes its membrane from the cell that it infects, the researchers explained in their study. This membrane contains cholesterol, which helps keep it fluid and enables it to interact with particular types of cell.
Normally, a subset of immune cells called plasmacytoid dendritic cells (pDCs) recognize HIV quickly and react by producing signaling molecules called interferons. These signals activate various processes which are initially helpful, but which damage the immune system if switched on for too long.
Working with scientists Johns Hopkins University, the University of Milan and Innsbruck University, Boasso’s team found that if cholesterol is removed from HIV’s envelope, it can no longer activate pDCs. As a result, T cells, which orchestrate the adaptive response, can fight the virus more effectively.

[cesar67]

very intersting, but as always has been the case with this deadly evil, prevention is better than the cure.
i have went bareback before in my early days of los, and i am just thankful that i came out un scathed.
please bag up!!!! especially when drunk

[pied]

Imagine AIDS going away. Thanks for the article.

[transgirls]

pied, on 24 September 2011 - 12:15 AM, said:

Imagine AIDS going away. Thanks for the article.

still leaves HEP C.
but it is much more difficult to get than AIDS, agreed.

[pimpgreen]

I'm still bagging up Aids or no Aids,
there'll always be nasty little things out there you can catch,
always well as the big one.

[Bwana_LB]

Don't hold your breath. Note that the article talks about scientists "hoping" this leads to a vaccine. Those hopes have been dashed many times in the past. HIV is a tricky virus.

[roscoe]

A battle is won in small steps ... AIDS will have to be fought by attacking metabolic pathways, not with a silver bullet ... the cure will be a sidetracking of the overall process by which it works

[bluesman55]

WORLD AIDS DAY

Radical AIDS research funded in Canada
CBC – 5 hours ago

As people around the globe mark World AIDS Day, researchers continue to grapple with a disease for which there are treatments but no known cure.

Some believe that defeating a scourge as cunning as HIV requires an innovative solution, which is why two Canadian researchers have been given funding to explore radical theories about how to kill HIV-infected cells.

“The virus mutates, so it’s not like there’s a stable object there, so that for 10 years we know what the stable object is and we can keep doing research on this thing we call HIV,” says Peter A. Newman, Research Chair for Health and Social Justice at the University of Toronto.

“The virus is constantly mutating, so in talking about vaccines, for example, it’s very difficult to know how to target it.”

According to a 2010 report by the United Nations, about 33 million people worldwide are living with HIV/AIDS — two-thirds of them in sub-Saharan Africa. While an increasing number are receiving treatment, there is no vaccine as yet.

Last month, the Bill and Melinda Gates Foundation announced that Andrès Finzi, a researcher at the Centre Hospitalier de l’Université de Montréal, and Mario Ostrowski, an infectious disease consultant in Toronto, had each won a $100,000 grant for their research into killing HIV, the virus that causes acquired immunodeficiency syndrome (AIDS).

The goal of the HIV virus is to go into human cells, replicate itself and then infect other cells. To do so, it has developed a unique "key" called envelope glycoprotein, which attaches to a lock called CD4 to gain access into human cells.

Finzi's lab is trying to understand how the key on HIV particles works and, as he puts it, “mettre un baton dans la roue,” a French expression that means throwing a wrench in the works. More specifically, he hopes to block the HIV virus from even attaching to human cells.

Originally from Patagonia, Argentina, Finzi opened his lab in Montreal in September 2011, after spending four years doing his post-doctoral work at Harvard.

In his submission to the Gates Foundation, Finzi proposed killing HIV cells through a Trojan horse method he calls “reverse fusion.” In this experimental process, Finzi’s lab would create toxic viral particles that have the lock, rather than the key, and thus would attack HIV-infected cells. Once these cells bound themselves to the toxic particles, the toxic particles would deliver toxic genes that would kill the HIV-infected cells.

“I have done work in the lab that says this concept works, but now I’ve got the support to be able to push this idea forward, to see if we can really kill the cells,” says Finzi.

“This phase of the grant is just a proof of concept: are we specifically able to kill HIV infected cells? We need to do that in a way that’s not going to harm other cells.”

Hide and seek

Ostrowski’s lab, meanwhile, is looking at ways to boost the immune system’s ability to detect HIV.

People diagnosed with HIV are currently treated with a “cocktail” of anti-retroviral drugs. One of the inherent snags is that patients must stay on the treatment for life; if they go off it, the HIV virus runs amok in the body again. That’s because the ever-mutating virus has a way of hiding out in parts of the body where the immune system cannot detect it — in what are known as virus reservoirs.

Ostrowski is looking to help the immune system suss out and kill these fugitive virus particles.

“The way immune cells kill virus-infected cells is through something called a killer cell,” says Ostrowski. “When the immune system makes these killer cells, they can recognize virus antigens on the surface of an infected cell, and eliminate the virus from the body. However, HIV can mutate and escape recognition by the killer cells.”

So how would these killer cells find the elusive HIV virus?

As Ostrowski points out, up to 40 per cent of our chromosomes contain codes for DNA left over from extinct, million-year-old viruses, and about eight per cent of our DNA is from a virus similar to HIV, known as human endogenous retrovirus (HERV). Why it’s there remains a scientific mystery, but Ostrowski's group has learned that when a human cell is infected with HIV, that same cell also starts showing proteins from these ancient viruses.

In taking immune cells from an HIV-infected person, Ostrowski’s team discovered a killer cell that could detect these HERV proteins. This is key, because the HERV proteins can't mutate like HIV does. So for the Gates grant, Ostrowski proposed creating a vaccine that would force the immune system to target these HERV proteins and attack those HIV-infected cells, in the hopes of getting rid of the HIV reservoir.

Ostrowski’s team will take these killer cells and expand their numbers in test tubes.

“Then we’ll add them to cells that are infected with HIV, and we’re going to see if these killer cells can completely eradicate the virus in tissue culture.”

Funding the unconventional

Finzi and Ostrowski’s projects are among 15 proposals to receive money from the Gates Foundation for HIV research. According to Michal Fishman, a senior communications officer for the foundation, there were 398 submissions for this topic in this round of funding.

Launched in 1994, the foundation is dedicated to enhancing healthcare and reducing extreme poverty around the world. Through its Grand Challenges in Global Health initiative, the foundation finances medical research of a decidedly radical nature.

“The funding is really based on the idea itself,” says Fishman, who says that Finzi and Ostrowski have the next 12 to 18 months “to prove their hypothesis.”
If the results are favourable, the Gates Foundation will give them an additional $1 million for a second phase of research.

Ostrowski says that private endowments like the Gates grants can further ideas more quickly than government grants, which often require preliminary data that can take years to accumulate.

Newman says that this insistence on data can often work against innovation.

“The most innovative ideas are things that are outside the box or are using ways of approaching a problem or issue that haven’t been tested before,” says Newman.

Edited by bluesman55, 02 December 2011 - 02:20 AM.