Synthetic peptide platform to make orally active, room-temperature vaccines
Scientists from James Cook University in Australia and Cardiff University in Wales have made a synthetic influenza A vaccine using the platform, as detailed in a study to be published in next month’s Journal of Clinical Investigation.
The proof-of-concept study shows vaccinated mice were protected from potentially lethal doses of swine flu, as were human cells in the laboratory.
James Cook University’s John Miles told us the researchers ran a T-cell combinatorial peptide library made with D-amino acids to develop the vaccine.
“These are mirror images of the L-amino acids that are the building blocks of all proteins.
“We were attracted to them because they’re very stable, meaning these compounds are harder to break down,” he said.
The team built a synthetic peptide agonist for the vaccine.
“We were very surprised at how flexible the immune system is in recognizing dangerous targets,” said Miles.
“It can’t actually tell the difference between our antigen and a real-world fragment of swine flu.”
Temperature control?
As the new compounds are composed of strings of D-amino acids – which are resistant to physical and enzymatic degradation – Miles said the vaccine ‘bypasses’ the need for cold chain storage and transportation.
Cardiff University’s Andrew Sewell similarly said that in theory, the synthetic vaccine could be stored at room temperature over its entire lifecycle, without ever going out of date.
“In addition to being expensive, maintaining a cold chain of delivery can be extremely difficult in remote areas of the globe,” explained Sewell.
“In hot places without reliable electricity, this can count for the majority of the cost of vaccines, and significant wastage,” he added.
‘Orally active’
The study also shows the synthetic vaccine is stable in stomach acid and human blood.
“To be administered orally, vaccines need to be able to survive the acids and enzymes in our stomachs. A couple – including the polio vaccine – can do this, but most cannot,” explained Miles.
“We also have evidence that the vaccine is orally active,” he told us, adding: “This could possible bypass the need for needles. Vaccines could be made in pill form.”
Miles told us he hopes to license out the agonist generating platform, adding that “it can be used for any disease.”
"We have some further work to do in making these vaccines work across larger populations and against other bugs and possibly cancer," he said.
"But what we have now is a promising platform for synthetic vaccine production.”
