'Spider' protein can deliver stable vaccines in high concentration

A "spider protein," C4BP, is capable of delivering vaccines in high concentration.--Courtesy of Helmholtz Centre

German researchers are using the highly stable structure of a uniquely shaped human immune protein as a model for high-concentration vaccine delivery.

The protein C4BP acts as a countermeasure against bacteria in the blood under normal conditions. One of many such immune proteins, C4BP has 8 "arms," or chains--7 alpha chains and one beta chain--held together by a central "body" called the oligomerization domain. Looked at under a microscope, the entire molecule resembles a spider--which led the scientists at the Helmholtz Centre for Infection Research and the Technische Universitat Darmstadt to call C4BP the "spider protein."

But what's important about the structure in a drug-delivery context, according to a study published in the international Journal of Molecular Biology, is that the central body of the molecule keeps the protein together and active despite the harsh environment of the bloodstream. So, scientists can use the centralized body of a synthetic version of the spider protein as a platform for drugs, essentially replacing any number of the 7 alpha chains with new treatments.

Because of the highly stable structure, large-molecule drugs such as vaccines will reach their target. And by grouping up to 7 vaccine molecules together around the central body, it's possible to create a sevenfold more concentrated vaccine effect. By doing so, it could be possible to reduce the dosage while similarly kick-starting the immune system.

- here's the Helmholtz Centre release
- get the research abstract