New mechanism that attacks viral infections discovered

Researchers at medical centers in universities in Mainz and Freiburg, Germany, have discovered a mechanism used by the innate immune system to control viral infections such as rotavirus -- the most common cause of pediatric diarrhea.

The research results were published recently in Nature Immunology, a major scientific journal.

The innate immune system is naturally equipped to fight viruses, bacteria and parasites. Interferons -- special proteins that are quickly released when a viral infection is present -- play a vital role in antiviral defense. In tandem, innate lymphoid cells (ILCs) are active inside and outside the body, producing special proteins that are present in the early stages of infection.

The researchers used rotavirus to demonstrate how an infection could be fought off.

"We were able to show that interferon-lambda (IFN-?), although a required factor, is not capable by itself to control rotavirus infection but that the presence of interleukin-22 (IL-22) is also necessary to effectively combat rotavirus," Professor Andreas Diefenbach of the Department of Medical Microbiology and Hygiene of the Mainz University Medical Center said.

Interleukin-22 defends the intestines and lungs against bacterial infections. It also is part of the tissue repair process in the intestines if they are damaged.

"Our new discovery that interleukin-22 acts as a sort of reinforcement for interferon is so exciting because it could have implications for the design of future immunotherapy concepts," Diefenbach said.