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, according to research led by the University of Oxford.
The researchers suggest that a vaccine 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," says 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," says 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 Proceedings of the National Academy of Sciences.
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.