Researchers edge closer to making HIV vaccine

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  1. A.V.

    A.V. New Member

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    WASHINGTON: Researchers have edged closer to developing a vaccine to guard against HIV infection, by targeting a vulnerable piece of the virus.



    Gail Ferstandig Arnold and Eddy Arnold, husband and wife duo and their team at Rutgers University, had previously been able to elicit effective antibodies, but only against a very limited number of HIV types.

    While most vaccines are actually made from the pathogen itself, employing weakened or inactivated organisms to stimulate antibody production, HIV is just too dangerous to use as the basis for a vaccine vehicle.

    What the Arnolds have now done is to use the relatively innocuous cold-causing rhinovirus and attach the target portion of the HIV. This must be done in a way that maintains the HIV part's shape so that when the immune system sees it, it will actually mount an immune response as it would to the real HIV.

    The approach taken by the Arnolds and colleagues has been to identify a part of the AIDS-causing virus that is crucial to its viability - something the virus needs in order to complete its life cycle - and then target this Achilles' heel.

    "The part that we targeted plays a role in the ability of HIV to enter cells, and is common to most HIV varieties," Arnold said. "That is a mechanism that would not be easy for the virus to reinvent on the fly, so it turns out to be a really helpful target."

    With HIV's known propensity to mutate, antibodies developed against one local strain may not recognise and combat mutant varieties elsewhere.

    These geographic varieties with different mutations constitute one of the great challenges to finding a broad spectrum vaccine capable of protecting against HIV.

    "The idea is to trick the immune system into thinking it is acting upon HIV before the virus shows actually shows up on the scene," said Eddy Arnold.

    To actually accomplish this is a big problem in engineering. The goal was to take a small piece of the HIV out of its native context, put it in a completely different system (rhinovirus), and have it look the same and act the same.

    Eddy Arnold likens this to taking the Rocky Mountains, putting them on India and having them look exactly right, said a Rutgers release.

    Using recombinant engineering, the research team developed a method to systematically test millions of varied presentations of the HIV segment with the rhinovirus. They tried millions of different variations on how to graft (or splice) one onto the other, creating what are called combinatorial libraries.

    "It's like the lottery," Eddy Arnold commented. "The more tickets you buy the better chance you have of winning."
     
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  3. shiv

    shiv Regular Member

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    Secrets of Aids 'immunity'

    dint some european guys found a cure for AID's.

    Scientists have identified why some HIV patients are immune from developing full-blown Aids.

    It has been known for some time that around 2% of HIV patients were protected in some way.

    But now, American and Chinese researchers have identified a group of proteins in the body which naturally block HIV developing into Aids.

    They say the discovery, detailed in the journal Science, could lead to better understanding of how the body fights HIV, and could potentially lead to the development of new treatments.


    This discovery is a major step forward in our understanding of how the body fights HIV

    Dr Linqi Zhang, Aaron Diamond Aids Research Center
    A second study to be published in The Lancet on Friday shows that a common spermicide which had previously been proposed as a preventative agent against HIV infection is ineffective.

    Nonoxynol-9 spermicide can be bought over-the-counter, and it has also been suggested it could protect against other sexually transmitted infections.

    But Belgian researchers say Nonoxynol-9 could even increase HIV transmission if used frequently.

    Proteins

    Scientists have known since the mid-1980s that some people with HIV do not go on to develop Aids.

    Immune cells, called CD8 T cells, were discovered to produce some unidentifiable factors which inhibited HIV cells from replicating.

    In this research, scientists from the Aaron Diamond Aids Research Center in New York City compared CD8 T cells from HIV patients who had not developed Aids with those from patients whose immune systems were beginning to fail.

    They found that those who remained healthy had the alpha-defensins -1, -2, -3 proteins.

    The proteins appeared to suppress all strands of HIV, and the researchers suggest they could be developed to suppress HIV in the greater infected population.

    To confirm their finding, the researchers artificially stripped the proteins from the cells of protected HIV patients.

    They found that the cells ability to fight HIV was virtually eliminated.

    Further research showed a synthesized versions of the proteins was 10 to 20 times less effective than the natural version.

    Vaccination possibility

    Dr Linqi Zhang, who led the research, told AFP news agency: "This discovery is a major step forward in our understanding of how the body fights HIV.

    "By understanding how some people's immune systems are able to control HIV infection, we may be able to develop new treatments that take advantage of this phenomenon."

    Keith Alcorn, editor at the UK National Aids Manual, told BBC News Online: "This is an interesting discovery, but as always the key issue is how well it will work in humans, and how easy it will be to synthesise it in the quantities needed to treat humans, given that the synthetic form is far less potent than the naturally occurring form".

    "Another avenue for development of this discovery into a treatment might be to look for agents or vaccination strategies which stimulate the body's own production."

    Lesions

    Researchers from the Institute of Tropical Medicine in Antwerp, Belgium, looked at the effectiveness of Nonoxynol-9 spermicide gel by studying 765 HIV negative sex workers in South Africa, Côte d'Ivoire, Benin, and Thailand.

    Around a third of women used the spermicide gel an average of three and a half times a day.

    This was associated with a doubling of HIV infection compared with women using a dummy gel.

    Researchers suggest this could have been because of the occurrence of vaginal lesions as a result of intensive use of the gel.

    However, low use of the gel did not increase the risk of HIV infection.

    There was also no differences in the incidence of other sexually transmitted diseases between Nonoxynol-9 and dummy gels.

    Dr Lut Van Damme, who led the study, said: "Nonoxynol-9 no longer has a part to play in HIV-prevention.

    "Our data show that low frequency use of nonoxynol-9 causes neither harm nor benefit; but that frequent use increases a woman's risk of HIV-1 infection by causing lesions."

    But in an editorial in the Lancet, Dr David Wilkinson from the University of South Australia, Adelaide, Australia, said the findings should not mean that the search for methods to reduces the risk of acquiring HIV loses momentum."

    Commenting on the study, Lisa Power, head of policy at the Terrence Higgins Trust, which is calling for the removal of Nonoxynol 9 from condoms and lubricants, said: "There is no basis for the use of Nonoxynol 9 as an anti-HIV agent.

    "Research shows that in fact it is liable to increase the possibility of transmission.
     
  4. shiv

    shiv Regular Member

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    Hawa Chelangat, 34, is among a group of about sixty women in Nairobi who have remained HIV negative for three years or more, despite daily exposure. Her fascinating story is one more scientific proof that many individuals are ''learning'' to develop immunity to AIDS.

    The story began to unfold in Nairobi (Kenya) in the mid-90s when Canadian scientist Dr. Frank Plummer, principal researcher at a clinic in Majengo, Nairobi, was conducting research on STD's[1]. Living in an environment of desperate poverty, many of the women in Majengo turn to prostitution to support their families, and come to the clinic there. When Dr. Plummer learned that about two-thirds of these women tested HIV-positive, he shifted the focus of his research to AIDS. That's when they discovered that a small number of the women had apparently developed an immunity to the HIV virus.

    The research team, according to an article in the CNN archives,[2] were ''astounded'' by the number of women who had become AIDS-free. Still, they refused to use the word immunity to describe what was happening. According to an Associated Press story quoted in Life magazine, Dr. Plummer said:

    ''We are calling it resistant -- we are not calling it immune -- but we have a lot of evidence that their immune systems are able to recognize and kill HIV. We think there's something fundamentally different about their immune systems that is mediated by genetics, and we're trying hard to track it down.''[3]

    Most of the immune women were related to each other by blood, and this is what gave the scientists the clue that the immunity might be explained by the women's genetic makeup. ''But it could be a combination of several factors,'' another researcher commented. And he added, ''They could be immune to a combination of things, and HIV is just one of them.''

    According to the CNN story, the running theory on HIV immunity is that certain proteins -- human leukocyte group A antigens -- trigger a more powerful immune response to the HIV virus, and scientists believe that by studying natural AIDS immunity they may be able to develop a vaccine that will do the same thing.

    More recently, however, at the January 30-February 2 Conference on Retroviruses in San Francisco, Plummer's group had distressing news: a couple of the ''HIV-resistant'' women they were studying became HIV-positive between 1996 and 1999.[4] The startling fact, however, was that the ones who became infected, unlike the 90% who were still HIV-free, had actually started using protection, so that they were no longer exposing themselves to the virus!

    Because the medical paradigm does not take account of the influence of mind and spirit upon our bodies, the scientists were forced to invent some new theory of resistance in order to explain what had happened to these women. Dr. Kevin de Cock, HIV specialist at the National Centers for Disease Control, sums up the official position, concluding that ''HIV antigen stimulation is required for the maintenance of resistance.'' (Meaning no disrespect, this conclusion seems to this writer to boil down to the advice that the best way to prevent AIDS is to have unprotected sex every day with at least one diseased partner.)

    But the women who became infected with HIV had one thing in common besides the lack of exposure, and that was fear. Even though they had, with total impunity, been exposed to HIV daily for the past eight to thirteen years, they were still afraid. As the Spirit of Ma'at showed in our August issue, it is the combination of emotion, thought, and action that enables us to shapeshift our environment. In this case the emotion was fear, the thought was that they would contract AIDS, and the action was to take protection. If mind can change our DNA in a forward-looking direction, it can also change it back.

    ''It has been so difficult for me,'' says Hawa Chelangat's cousin Hadija, most of whose friends have been infected by HIV, ''because you see people around you go down with HIV and AIDS, and it's a natural fear that one day my blood will turn positive and I will die.''

    But if the conclusions in this issue of the Spirit of Ma'at are correct, even if Hadija's own fear creates a negative outcome for her, what is also likely to happen is that more and more of the women in the ''world's oldest profession'' -- not only in Nairobi, but worldwide -- will develop immunity to AIDS. And as Drunvalo and Gregg Braden and many others believe, the deep spirituality of the Nairobi women may offer a clue to the selection process.

    As Hawa Chelangat says, ''I feel because my blood has remained good, it is a blessing from God.''

    http://www.spiritofmaat.com/archive/oct1/nairobi.htm
     

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