Fluorescent reporter allows imaging of single cells infected with hepatitis C

Hepatitis C virus (HCV) infects 2 to 3 percent of the world population. The recent development of methods to culture the virus may lead to antiviral therapies, but better imaging methods are needed to understand the infection process. In the February issue of Nature Biotechnology researchers at Rockefeller University, MIT and other institutions report on a cell-based fluorescent reporter that allows imaging of live or fixed individual HCV-infected cells.

They constructed the reporter by fusing a fluorescent protein--either EGFP, mCherry, or Tag RFP--to the C-terminal region of a known substrate of the HCV NS3-4A protease. They were able to use this reporter to distinguish between infected and uninfected cells and to image previously unseen events such as viral propagation and host response. The researchers used a Nikon Eclipse TE300 for wide-field fluorescence imaging, a Zeiss inverted Axiovert 200 laser scanning confocal microscope for imaging fixed samples, the Axiovert 200 with a Perkin-Elmer spinning-disk confocal head for imaging live samples, and a Olympus IX71 inverted microscope for time-lapse imaging.

The reporter system doesn’t require genetic modification of the viral genome and worked for all the HCV genomes they tested, which gives it potential for use in identifying new infectious isolates directly from patient samples, according to the researchers. They were also able to combine the HCV reporter with a fluorescent marker of cellular stress to correlate viral and host events.

Research Paper:
Real-time imaging of hepatitis C virus infection using a fluorescent cell-based reporter system, Nature Biotechnology 28, 167 - 171 (2010) 
doi:10.1038/nbt.1604