Swiss Mymetics Corporation

[hahaha]

Anybody knows about the detail of the following story from Gay.com.uk?
__________________________________________________________

For the first time, a vaccine designed to elicit the kind of immune response that could stop HIV entering the body in the first place has produced positive results, in tests in monkeys.

The Swiss Mymetics Corporation has produced a vaccine that consists of an artificial virus that churns out a peptide - a protein fragment that is in fact crucial part of the gp41 protein, the part of the HIV virus that actually injects its genetic material into the cell.

Scientists from Mymetics introduced the vaccine vaginally or rectally into monkeys like a lube and then introduced HIV in simulated sex. They were then able to prove that they then had a mucosal immune response. This meant that the vaccine was able to inhibit a process called transcytosis by 60 to 98 per cent, depending on the strain of HIV used.

In transcytosis, which is one of the mechanisms of infection, HIV penetrates the cells that line the vagina or rectum and, without infecting them as such, literally ‘travels across’ the cell and emerges the other side into the body cavity, where it can get into the bloodstream and find the cells it actually does like to infect.

The vaccine was able to prevent this by getting the monkeys to produce large amounts of so-called ‘broadly neutralising antibodies.’

What does this mean? The part of the gp41 protein the vaccine makes is only exposed to the outside environment during the natural lifecycle of HIV for a few fractions of a second – the time it takes for the virus to fuse with a cell. However because it’s such a vital part of HIV’s ‘machine’, it varies little between viral strains. In the language of genetics, it is ‘highly conserved’.

That means that if the human body is exposed to this gp41 peptide, it will produce what are called ‘broadly neutralising’ antibodies. In other words, they will be active against a wide variety of HIV strains and will be able to block the crucial fusion moment.

That’s the theory, anyway, and scientists have shown that broadly neutralising antibodies (called things like 2F5, 4E10 and b12) do prevent HIV infection in themselves. But antibodies, if injected, disappear from the body very fast, just as normal drugs do.

Indeed some current anti-cancer drugs like Herceptin are antibodies. What is needed is what a vaccine does – a ‘mock infection’ which gets the body to turn out a constant supply of anti-HIV antibodies.

More than 90 per cent of monkeys immunised with the artificial gp41-producing virus produced high levels of IgA in their vaginas and rectums. This is a generic antibody type which, when tested, proved to be as good as or better than the best broadly neutralising antibodies at making even quite virulent strains of HIV incapable of infection.

The reason this advance is so significant is because the HIV vaccines most scientists are testing are so-called Cellular Immune Response vaccines. What that means is that they won’t actually prevent HIV infection; they will just target HIV-infected cells and hopefully turn HIV infection into a benign condition.

But an effective antibody vaccine - a so-called Humoral Immune Response vaccine - should be able to prevent infection in the first place.

Sylain Fleury, Mymetics’ lead scientist, said: “These results are extremely encouraging. We are the first group to report neutralising IgA obtained after vaccination in non-human primates. It could potentially work at low concentrations.”

He added that the vaccine didn’t require an adjuvant, which is an irritant chemical used in some vaccines to strengthen an immune response. This is fortunate as none are licensed for vaginal or rectal use in humans.

Fleury added that Mymetics intended to test an improved vaccine later this year and that if this also produced positive results, “we may be able to initiate a clinical trial [in humans] and begin phase I testing some time in late 2008.”

[frenchpat]

Read:

http://www.mymetics.com/

and

http://www.mymetics.com/mymetics_pages/technology_mymetics_01.htm

Pat


edited to add 2nd link

[hahaha]

Read:

http://www.mymetics.com/

and

http://www.mymetics.com/mymetics_pages/technology_mymetics_01.htm

Pat


edited to add 2nd link

Thanks.  Obviously it is only for prevention purpose.  Would wondering if it also has certain kind of therapeutic effect if HIVer is on Haart and VL is undetectable?

[Cerrid]

Thanks.  Obviously it is only for prevention purpose.  Would wondering if it also has certain kind of therapeutic effect if HIVer is on Haart and VL is undetectable?

I'd think if the antibodies were able to fish for HIV, then they would be extremely useful for therapeutic purposes, too. It's another building block to stop replication and re-infection.