Fluoromodule-based reporter/probes designed for in vivo fluorescence imaging

J Clin Invest. 2015 Oct 1;125(10):3915-27. doi: 10.1172/JCI81086. Epub 2015 Sep 8.

Abstract

Optical imaging of whole, living animals has proven to be a powerful tool in multiple areas of preclinical research and has allowed noninvasive monitoring of immune responses, tumor and pathogen growth, and treatment responses in longitudinal studies. However, fluorescence-based studies in animals are challenging because tissue absorbs and autofluoresces strongly in the visible light spectrum. These optical properties drive development and use of fluorescent labels that absorb and emit at longer wavelengths. Here, we present a far-red absorbing fluoromodule-based reporter/probe system and show that this system can be used for imaging in living mice. The probe we developed is a fluorogenic dye called SC1 that is dark in solution but highly fluorescent when bound to its cognate reporter, Mars1. The reporter/probe complex, or fluoromodule, produced peak emission near 730 nm. Mars1 was able to bind a variety of structurally similar probes that differ in color and membrane permeability. We demonstrated that a tool kit of multiple probes can be used to label extracellular and intracellular reporter-tagged receptor pools with 2 colors. Imaging studies may benefit from this far-red excited reporter/probe system, which features tight coupling between probe fluorescence and reporter binding and offers the option of using an expandable family of fluorogenic probes with a single reporter gene.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Activation, Metabolic
  • Aniline Compounds / analysis*
  • Aniline Compounds / pharmacokinetics
  • Animals
  • Cell Line
  • Cell Membrane Permeability
  • Color
  • Deamino Arginine Vasopressin / pharmacology
  • Endocytosis / drug effects
  • Fluorescence
  • Fluorescent Dyes / analysis*
  • Fluorescent Dyes / pharmacokinetics
  • Genes, Reporter*
  • Green Fluorescent Proteins / analysis
  • HCT116 Cells / transplantation
  • Humans
  • Intravital Microscopy*
  • Mice
  • Mice, Nude
  • Neoplasms, Experimental / chemistry
  • Neoplasms, Experimental / ultrastructure*
  • Optical Imaging / methods*
  • Peritoneal Neoplasms / chemistry
  • Peritoneal Neoplasms / ultrastructure
  • Receptors, Vasopressin / analysis
  • Receptors, Vasopressin / genetics
  • Recombinant Fusion Proteins / analysis
  • Recombinant Fusion Proteins / metabolism
  • Single-Chain Antibodies / analysis*
  • Single-Chain Antibodies / metabolism
  • Structure-Activity Relationship
  • Subcellular Fractions / metabolism
  • Subcellular Fractions / ultrastructure
  • Transduction, Genetic

Substances

  • AVPR2 protein, human
  • Aniline Compounds
  • Fluorescent Dyes
  • N-(4-(1,3-bis(4-(dimethylamino)phenyl)allylidene)cyclohexa-2,5-dien-1-ylidene)-N-methylmethanaminium
  • Receptors, Vasopressin
  • Recombinant Fusion Proteins
  • Single-Chain Antibodies
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • Deamino Arginine Vasopressin