A bit of bug spit could be a good thing
Sun, 25th Mar 2007
Download as mp3
from the show The Science of Flight
New research out this week hints at a ray of hope in the battle against malaria – and it seems the answer could be a rather simple ingredient – mosquito spit. Every year somewhere between one and three million people die of malaria and the search for an effective vaccine is a huge challenge facing medical researchers today.
Scientists had already discovered that the saliva of sand flies can help protect against an insect-borne skin disease called leishmaniasis. And now a new study by Mary Ann McDowell and her team at the National Institute of Allergy and Infectious Diseases in Maryland in the US has shown that mice pre-exposed to mosquitoes that don’t carry malaria have better protection against the disease when they are later bitten by infected mosquitoes. Mice with uninfected mosquito saliva in their blood were found to have lower levels of the malaria parasite. The non-infected saliva stimulated the immune systems of the mice to produce infection-fighting chemicals called cytokines which are mostly associated with immune cells called T-helper 1 cells.
Of course it’s early days and we are a way off seeing a new anti-malaria vaccine based on mosquito spit, but McDowell and her team are already on to the next step and are hunting for the particular protein that is responsible for this immune response in mice – when they find it they will need to test whether the protein is also effective in humans.