Dr. Mossman’s group focuses on understanding how viruses evade host immune defenses. When a virus infects a host, the host mounts an impressive immune response aimed at preventing the virus from multiplying and spreading. Viruses have evolved strategies to block this response in order to ensure their survival. Probably the most important aspect of the host immune response to virus infection is the production of an immune modulator called interferon. Interferon has a great impact on host defense mechanisms, and as a result, viruses have evolved multiple strategies to overcome its activities.
The Mossman Lab studies the mechanisms of interferon inhibition and the countermeasures taken by different viruses. These studies have led them to develop viruses for use in gene therapy and cancer therapy. They focus on herpes simplex virus type 1 (HSV-1), a human pathogen that causes cold sores, and have found that by disabling the virus through the removal of particular genes, the virus can grow in cancer cells and kill them while having no effect on healthy cells. Such viruses, called "oncolytic viruses", are currently being tested as a novel approach to cancer therapy in the hopes of eliminating tumors without the toxic side effects associated with many current treatments. HSV-1 is also being studied as a tool for gene therapy, since it is easy to manipulate, can be targeted to specific tissues, and can house several therapeutic genes in a single vector.
Thus, the overall goal of the Mossman Lab is to understand how viruses and their hosts interact with each other so they can use viruses as tools for the treatment of multiple diseases.