3 MIN READ

A tick in the box

Inspirational medical solutions can come from the most unlikely places.

For example, venom from the Brazilian viper was an early ACE-inhibitor, used to treat blood pressure (captopril) and Foxglove toxin (digoxin) for atrial fibrillation. The brilliant Professor Shoumo Bhattacharya, BHF Chair in Cardiovascular Medicine, has found his inspiration in the humble tick.

Well-known and equally loathed by pet-owners and ramblers, ticks survive by attaching themselves to their live animal or human host and sucking their blood. Quite apart from it being an unpleasant habit, some ticks can also carry and infect their host with the bacteria responsible for Lyme disease.

tick-on-skin

A tick needs to feed from its host for a period of up to 10 days before it is able to fall off. This requires a “stealth operation”, to make sure their unwitting host does not notice the tick is on-board. The key to this subterfuge, is the tick’s saliva. The insect injects more than 3,000 proteins, which block both pain and inflammation and this is where the connection with Prof Bhattacharya’s research comes in. He is looking at the role of inflammation in some types of heart disease, a result of the response of the body’s immune system.

Infection or injury to the heart, such as in the case of MI, myocarditis and other conditions, results in the release of chemokines. These signal that there is a problem and white blood cells are mobilised to deal with the problem. However, in some cases chemokines can over-compensate and cause inflammation in the heart. A dangerous vicious circle sets in, in which inflammation leads to the release of more chemokines. An inflamed heart does not function effectively and in some cases the outcome can be fatal.

Enter the use of tick saliva, which contains evasins, substances which are able to take out the chemosines and so neutralise their negative effect on the heart. Clearly, harvesting enough volume of tick saliva to work with is challenging.

Fortunately, Prof Bhattacharya’s research team have developed a solution. By transferring genetic information from tick saliva into the sort of yeast used in brewing beer, evasins can be grown in the quantities required on the yeast medium. Whilst we are probably not ready to take it to our hearts, it is extraordinary to know that the very mechanism that makes the tick an effective “predator” potentially holds the key to tackling serious and often fatal heart disease. Now that deserves a tick in the box, even for this reviled insect.

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