A genetically encoded bioluminescent indicator for illuminating proinflammatory cytokines

We introduce a method to evaluate the activities of cytokines based on the nuclear transport of NF-κB. A pair of bioluminescent indicators was made for conferring cytokine sensitivity to cervical carcinoma-derived HeLa cells. The principle is based on reconstitution of split fragments of Renilla reniformis luciferase (RLuc) by protein splicing with a DnaE intein from Synechocystis sp. PCC6803. The bioluminescence intensity of thus reconstituted RLuc in the HeLa cells was used as a measure of the activities for cytokines. With the present method, we evaluated the activities of various cytokines based on the nuclear transport of NF-κB in human cervical carcinoma-derived HeLa cells carrying the indicators. The present approach to evaluating the activities of cytokines may provide a potential clinical value in monitoring drug activity and directing treatment for various diseases related with NF-κB. The method highlights the experimental procedure from our original publications, Anal. Biochem. 2006, 359, 147–149 and Proc. Natl. Acad. Sci. U. S. A. 2004, 101, 11542. The summary of the method is: • Cytokine activities are determined within 2 h after stimulation. • Temporarily inactivated split-luciferase fragments are reconstituted by protein splicing. • Nucleartrafficking of NF-κB was illuminated for gauging the ligand-driven activity.