They are the scourge of the British countryside, feared for spreading Lyme disease. But ticks, the tiny biting creatures which feast on our blood, could hold the key to treating a ‘time bomb’ heart condition which strikes young people without warning.
Anyone who has suffered a tick bite, or found one on a family pet, knows ticks are masters of avoiding detection. But the same proteins in their saliva which allows ticks to feed on us for up to 10 days unnoticed could also prevent myocarditis – a potentially deadly heart condition, as well as heart attacks and strokes.
These proteins are important to the tick because they stop victims suffering swelling and pain, so that we do not notice them and knock them off our skin by scratching. However the inflammation the saliva prevents is also the cause of swelling of the heart muscle in people with myocarditis.
It means the spit of ticks, harvested in sufficient quantities, could save young people with the condition from the danger of heart failure or the need for a transplant. Professor Shoumo Bhattacharya, the study’s lead author and professor of cardiovascular medicine at the University of Oxford, said: ‘Myocarditis is a devastating disease, for which there are currently very few treatments.
‘With this latest research, we hope to be able to take inspiration from the tick’s anti-inflammatory strategy and design a life-saving therapy for this dangerous heart condition.’ Tick saliva’s important properties were first discovered in 2001, when scientists ‘milked’ ticks using a hair-thin tube to draw their spit out of their throats.
But it would take hundreds of thousands of ticks, which are just a few millimetres long, to produce enough saliva to treat just one patient. Instead, scientists have created synthetic tick genes in the lab, growing them in yeast.
This helped them to find one particular protein, from the cayenne tick found in the Americas, able to block the chemicals, called chemokines, which cause inflammation of the heart muscle. Professor Bhattacharya said: ‘These ticks are very clever and have evolved over 300 million years to be able to drink their fill of blood over eight to 10 days.
‘Unlike mosquitos which bite and fly off quickly, ticks are careful to prevent inflammation over this longer time period so people and animals are unaware they are there and do not knock them off. ‘Tick saliva has already been used to develop a drug used to treat a rare blood disease, and we hope that drugs to treat myocarditis, heart attack and stroke could also be developed from the proteins we have found in tick saliva.’
What is myocarditis? The inflammatory properties of tick saliva are important because figures show more than 3,000 people a year seek medical help for myocarditis. The condition, which tends to affect young people, occurs when the heart muscle becomes inflamed and is often caused by common viruses such as ear and chest infections.
Almost a third of those with myocarditis go on to develop dilated cardiomyopathy and heart failure, which in severe cases can result in the person needing a heart transplant.
A potential drug? It is hoped the protein from tick saliva, which contains around 1,500 to 3,000 proteins, could be used to create a drug injected to prevent worsening of the condition, which researchers hope could be available on the NHS within a decade.
The protein, called P991_AMBCA, binds to and blocks chemokines, the chemicals released in the heart which attract the cells which cause inflammation.
Responding to the research, published in the journal Scientific Reports, Professor Jeremy Pearson, associate medical director at the British Heart Foundation, said: ‘They may not be pretty, but these little creatures could hold the secret to better treatments for a whole range of diseases.
‘There’s a long way to go, but tick saliva looks like an exciting, albeit unconventional, area of research.’