Tick repellent for humans: antibodies could lead to future vaccine to reduce tick feeding

Image by John Tann (Flickr)

Ticks are small arthropods that feed on the blood of animals. In the process of feeding, ticks will ingest blood from their victim, extract nutrients for themselves, and spit whatever is left back into the host, like a really gross filtration system. When this happens, bacteria that reside in the tick gut may also get spit into the host. These foreign bacteria can cause disease. Ideally, the best way to tackle the diseases spread by ticks would be to prevent feeding rather than treating the disease. This study investigated antigens, molecules capable of stimulating an immune response, as a potential tool to stop feeding.

When ticks feed, they release proteins that suppress the host immune system. However, when some animals are repeatedly bitten by ticks they develop an immune response to the bites. This immune response leads to various negative outcomes for the tick, such as a decrease in the ability of the tick to reproduce, an increase in the time it takes for a tick to become full, and perhaps surprisingly, a decrease in body weight. Not all animals in the study mounted an immune response to repeated tick bites; guinea pigs and rabbits did, while mice did not. In blood collected from rabbits, the researchers identified antibodies that recognized three different tick proteins (the aforementioned antigens). They found that when rabbits were immunized with these antigens, nymph feeding was significantly impaired.

There is currently no vaccine to prevent Lyme disease or other tick-borne diseases. This study is important because it identifies tick antigens and corresponding antibodies that could be harnessed to develop such a vaccine.

Summary written by: Taylor Caddell

To read the full article, please click the following link:

Identification and Characterization of Ixodes scapularisAntigens That Elicit Tick Immunity Using Yeast Surface Display

Tim J. Schuijt, Sukanya Narasimhan, Sirlei Daffre, Kathleen DePonte, Joppe W. R. Hovius, Cornelis van’t Veer, Tom van der Poll, Kamran Bakhtiari, Joost C. M. Meijers, Eric T. Boder, Alje P. van Dam, Erol Fikrig

To learn how to protect yourself from Lyme disease, click here.

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