Near-infrared dual bioluminescence imaging in mouse models of cancer using infraluciferin
Cassandra L Stowe,
Thomas A Burley,
Helen Allan,
Maria Vinci,
Gabriela Kramer-Marek,
Daniela M Ciobota,
Gary N Parkinson,
Tara L Southworth,
Giulia Agliardi,
Alastair Hotblack,
Mark F Lythgoe,
Bruce R Branchini,
Tammy L Kalber,
James C Anderson,
Martin A Pule
Affiliations
Cassandra L Stowe
Cancer Institute, University College London, London, United Kingdom; Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom
Thomas A Burley
The Institute of Cancer Research, London, United Kingdom
Helen Allan
Department of Chemistry, University College London, London, United Kingdom
Maria Vinci
The Institute of Cancer Research, London, United Kingdom
Gabriela Kramer-Marek
The Institute of Cancer Research, London, United Kingdom
Daniela M Ciobota
The Institute of Cancer Research, London, United Kingdom
Gary N Parkinson
School of Pharmacy, University College London, London, United Kingdom
Tara L Southworth
Department of Chemistry, Connecticut College, New London, United States
Giulia Agliardi
Cancer Institute, University College London, London, United Kingdom
Alastair Hotblack
Cancer Institute, University College London, London, United Kingdom
Mark F Lythgoe
Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom
Bruce R Branchini
Department of Chemistry, Connecticut College, New London, United States
Tammy L Kalber
Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom
Bioluminescence imaging (BLI) is ubiquitous in scientific research for the sensitive tracking of biological processes in small animal models. However, due to the attenuation of visible light by tissue, and the limited set of near-infrared bioluminescent enzymes, BLI is largely restricted to monitoring single processes in vivo. Here we show, that by combining stabilised colour mutants of firefly luciferase (FLuc) with the luciferin (LH2) analogue infraluciferin (iLH2), near-infrared dual BLI can be achieved in vivo. The X-ray crystal structure of FLuc with a high-energy intermediate analogue, 5’-O-[N-(dehydroinfraluciferyl)sulfamoyl] adenosine (iDLSA) provides insight into the FLuc-iLH2 reaction leading to near-infrared light emission. The spectral characterisation and unmixing validation studies reported here established that iLH2 is superior to LH2 for the spectral unmixing of bioluminescent signals in vivo; which led to this novel near-infrared dual BLI system being applied to monitor both tumour burden and CAR T cell therapy within a systemically induced mouse tumour model.
