HIV's sugar coating offers new vaccine approach

Jul 20, 2010
HIV's sugar coating offers new vaccine approach

(PhysOrg.com) -- Oxford research suggests the chains of sugar molecules, or carbohydrates, that cover the outside of the highly variable HIV virus remain constant, are different from those found on human cells, and could form the basis of a promising new approach to an AIDS vaccine.

The chains of sugar molecules, or carbohydrates, that cover the outside of the highly variable HIV virus remain constant, are different from those found on human cells, and could form the basis of a promising new approach to an , according to research led by the University of Oxford.

The researchers suggest that a based on synthetic versions of the HIV carbohydrate coat, because it is so unchanging, could prime the body’s immune system to recognise the otherwise rapidly changing HIV virus and fight off any infection.

‘We’re used to flu vaccines being reformulated every year because new strains come along,’ said Dr Chris Scanlan of the Department of Biochemistry at the University of Oxford, who led the research. ‘Yet you will see more viral diversity develop in a single HIV patient in a single day than you will in the whole flu season this year across the whole of the UK. That is some challenge for developing a vaccine against HIV.

’We’re cautiously optimistic that this research could lead to a promising new approach for a vaccine against HIV/AIDS,’ said Dr Scanlan. ‘We’ve found something that doesn’t change across all classes of HIV - from viruses found in the USA to those in Uganda - and it’s something that can be made and manufactured.’

The team from Oxford University, The Scripps Research Institute in La Jolla, California, and the Ragon Institute in Boston, Massachusetts report their findings in the journal (PNAS).

The researchers were able to isolate the carbohydrate coating from different samples of live HIV-1 virus, representing typical viruses found in different parts of the world, and analyse their chemical structures for the first time. They found that the carbohydrates are unique and are found across all classes or ‘clades’ of HIV-1. Importantly, these carbohydrates are completely different to the patterns of sugars found on human cells.

The researchers also showed that existing vaccines being developed against HIV will not have the same carbohydrate structures within their formulations as the native HIV virus and so may not mimic this element of the virus adequately.

'The dense cloud of carbohydrates covering the virus has been called its ‘carbohydrate camouflage’ because the carbohydrate chains look like those on the outside of the body’s own cells, and so they aren’t normally recognised by the immune system,’ explained Dr Scanlan.

‘We’ve shown that HIV’s camouflage may be flawed. The carbohydrates on an are different to the body’s own cells, and that might give us an opportunity to attack.

‘It is possible to educate the immune system to these differences. You can include danger signals in your vaccine formulation to force the to take notice of particular structures. Some cancer vaccines in development use this approach, for example,’ he added.

The team now aim to come up with ways of making synthetic versions in the lab of the particular carbohydrates found on the outside of HIV. These could then be combined with an adjuvant - a factor that enhances the body’s immune response - to give a completely new vaccine candidate for evaluation.

The researchers have already shown in their PNAS paper that it is possible to modify a human cell line to produce the gp120 HIV protein with the correct carbohydrates attached. This is one way that the carbohydrates for any future vaccine could be produced.

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FredJose
not rated yet Jul 20, 2010
Mmmhhhh, sly, very sly attack vector to investigate. I hope it works!

Just as an aside - is that picture another artistic rendering of an HIV virus or is it a highly souped-up electon microscope image? I think the former. Will the writer(s) of these articles please indicate that?

Please correct me if I'm wrong.
ricci1003
not rated yet Jul 22, 2010
Is the reason a vaccine can't be developed because the alleged virus remains unisolated? Why is there still no definitive test for "HIV", not even PCR?

The wishful thinking of a heterosexual epidemic in the West 20 years ago failed to come to fruition. Instead all we hear about is "AIDS" in Africa. The thought occurred: Do Africans really have that much sex and so many partners. I decided to go and find out. I went to Uganda in 2004 and ended up spending most of the time there since then.

How can this go on in Uganda and nobody know or care?
Most of all the "AIDS" NGOs need to be exposed. Like the one this lab technicia works for called Mildmay (one of over 7000 AIDS NGOs in Uganda). I interviewed him last year in Kampala. Ugandan children exploited as guinea pigs with toxic drugs by prominent "AIDS" NGOs:
http://vimeo.com/10401254