Abstract Interferons are potent cytokines with antiviral activity that have been founded earliest. Different types of interferons have similar bioactivity , e.g. anti-viruses activity, anti-tumor activity and immune modulation. They are induced by virus infection and trigger the host defense by different mechanisms. Firstly, IFNs directly induce the expressionof effector proteins with antiviral activity, thus establishing a first line of defense. Secondly, they help to shape adaptive immunity, leading to long-lasting protection. Due to this key position of IFNs in antiviral defense, viruses have evolved effective countermeasures in order to successfully invade the host. By expressing so-called IFN antagonists, viruses interfere with either IFN induction, IFN signaling, or the action of IFN effector proteins.
|
