'DNA origami' provides measuring tool to show antibody effectiveness

Jan. 14 (UPI) -- A new method of measurement developed by scientists could be the key to making antibodies more effective, researchers say.

Researchers at University of Oslo have created a DNA origami, or a DNA-based design of precise nanostructures, to judge the most accurate distance from heavily packed antigens to get the tightest bond to antibodies within the immune system. These findings appeared Monday in Nature Nanotechnology.

"We have for the first time been able to accurately measure the distances between antigens that result in the best simultaneous binding of both arms of different antibodies," Björn Högberg, a professor at the Department of Medical Biochemistry and Biophysics at Karolinska Institutet and study lead author, said in a news release. "Distances of approximately 16 nanometers provide the strongest bond."

Vaccines use a mix of antigens, or substances that prompt the immune system to react, to help train the immune system to attack a virus. The body recognizes the antigens within the virus it's already been exposed to, helping to prevent it from a viral infection.

Antibodies, or immunoglobulins, play an important role in defending the body against infection by binding antigens. Antibodies use their Y-shape to bind an antigen molecule with each arm.

"By putting antigens on these DNA origami structures, we can manufacture surfaces with precise distances between the antigens and then measure how different types of antibodies bind to them," Högberg said. "Now we can measure exactly how antibodies interact with several antigens in a manner that was previously impossible."

The research focused on how far and how closely the antigens could be packed from one another without drastically reducing an antibody's ability to bind the molecules at the same time.

The study also revealed that immunoglobulin M, or IgM, not only has a greater ability to connect two antigens, it has a much larger reach than IgG antibodies created at a later infection stage.

"We study the relationship between the structure and function of antibodies," said Jan Terje Anderson, a researcher at the University of Oslo and Oslo University Hospital.

"Such insight is important when we design the next generation of vaccines and antibodies for tailor-made treatment of serious diseases. We have long been looking for new methods that can help us get detailed insight into how different antibodies bind to the antigens," Anderson said.