Innate Immunity and Infection

The moment a pathogen, which has successfully entered the body, is recognized, the body quickly mobilizes its defenses. Interferons are molecules that are counted among the body’s first line of defense. They prevent proliferation and the spread of viruses in the body and serve to alert the immune system. Read here about the different ways we use to try and decode this system, all in an effort to find new approaches to infectious disease prevention and therapy.

Our Research

The interferon system is the body’s first line of defense against infections. It links up the body’s two most important lines of defense: the innate and the acquired immune response. The interferon system thus represents an important aspect of the body’s ability to defend itself against an infection. If the interferon system were missing, viruses would be allowed to proliferate unchecked, and protective immune responses like the ones triggered during a vaccination would not be able to develop properly.

Im Labor der Projektgruppe von Dr. Andrea Kröger.
Im Labor der Projektgruppe von Dr. Andrea Kröger.

Whenever we are attacked by a virus, everything has to happen very quickly. The interferon system promptly triggers a cellular anti-viral defense against the infectious agent. Viral products like nucleic acids are recognized by the cells via special receptors. “Toll-like“ receptors (TLR’s) or cytoplasmic sensor proteins like “retinoic acid-inducible gene I“ (RIG-I) recognize viral structures and quickly prompt the release of the first round of interferons. The released interferons are dispersed throughout the entire body. Other cells react by turning on certain genes whose protein products act to fight the viruses, thereby preventing viral proliferation. In addition, cells of the innate immune system are also alerted. These cells in turn activate and support the acquired immune response. Specialized immune cells of the innate immune response eliminate infected cells and quickly combat any re-infection with the virus.


Yet in spite of this highly effective defense system, there are viruses that can elicit chronic infections. Some viruses have evolved strategies for blocking the interferon system or evading detection by the cell’s own defense system. The interferon system’s regulatory proteins can trigger alternative defense mechanisms so that the cells don’t have to face the viruses unprotected.


The focus of the Innate Immunity and Infection research group is to understand how pathogens affect the interferon system, how alternative antiviral defense mechanisms work, and how the interferon system turns on the immune response. Thus, our scientists are laying the foundation for new strategies against serious viral infections and against cancer as well.