Bioluminescence imaging of reporter mice for studies of infection and inflammation

In vivo bioluminescence imaging offers the opportunity to study biological processes in living animals, and the study of viral infections and host immune responses can be enhanced substantially through this imaging modality. For most studies of viral pathogenesis and effects of anti-viral therapies, investigators have used recombinant viruses engineered to express a luciferase enzyme. This strategy requires stable insertion of an imaging reporter gene into the viral genome, which is not feasible for many RNA viruses, and provides data on the viral component of pathogenesis but not on the host. Genetically engineered mice with luciferase reporters for specific viral or host genes provide opportunities to overcome these limitations and expand applications of bioluminescence imaging in viral infection and therapy. We review several different types of reporter mice for bioluminescence imaging, including animals that permit in vivo detection of viral replication, trafficking of immune cells, activation of key genes in host immunity to viral infection, and response to tissue damage. By utilizing luciferase enzymes with different emission spectra and/or substrates, it is possible to monitor two different biologic processes in the same animal, such as pathogen replication and sites of tissue injury. Combining imaging reporter viruses with genetically engineered reporter mice is expected to substantially enhance the power of bioluminescence imaging for quantitative studies of viral and host factors that control disease outcome and effects of established and new therapeutic agents. (C) 2010 Elsevier B.V. All rights reserved.