Mini reviewUnderstanding Interferon Subtype Therapy for Viral Infections: Harnessing the Power of the Innate Immune System.

- The review focuses on the value of the type I and III interferon subtypes (alphas, beta and lambdas) as therapeutics for prevention and treatment of viral infections (influenza, herpes, human immunodeficiency virus and hepatitis viruses).
- The antiviral properties of the family of interferons have been widely recognised amongst the multiple subtypes.
- However, their unique modulatory effects on the immune system have attracted recent attention.
- This review covers the potential impact of interferon subtypes for immune intervention in both acute and chronic virus infections and explains how harnessing the power of the innate immune system effects disease progression and prognosis.

Type I and III interferons (IFNs) of the innate immune system belong to a polygenic family, however the individual subtype mediators of the antiviral response in viral infections have been hindered by a lack of reagents. Evaluation studies using different IFN subtypes have distinguished distinct protein properties with different efficacies towards different viruses, opening promising avenues for immunotherapy. This review largely focuses on the application of IFN-α/β and IFN-λ therapies for viral infections, influenza, herpes, HIV and hepatitis. Such IFN subtype therapies may help to cure patients with virus infections where no vaccine exists. The ability of cell types to secrete a number of IFN subtypes from a multi-gene family may be an intuitive counterattack on viruses that evade IFN subtype responses. Hence, clinical use of virus-targeted IFN subtypes may restore antiviral immunity in viral infections. Accumulating evidence suggests that individual IFN subtypes have differential efficacies in selectively activating immune cell subsets to enhance antiviral immune responses leading to production of sustained B and T cell memory. Cytokine therapy can augment innate immunity leading to clearance of acute virus infections but such treatments may have limited effects on chronic virus infections that establish lifelong latency. Therefore, exploiting individual IFN subtypes to select those with the ability to sculpt protective responses as well as reinstating those targeted by viral evasion mechanisms may inform development of improved antiviral therapy.