Background:

Human stem cells provide an unprecedented opportunity for the study of human tissue development and the development of cell-based therapies for human disease. For example, research is underway to develop stem cell therapies for major conditions such as cardiac disease, cancer, and diabetes. Many of these proposed therapies involve the controlled differentiation of pluripotent stem cells into a tissue of interest (i.e. a heart muscle, or pancreatic beta-cells) that can then be transplanted into a patient. While these therapies offer exciting promise, significant technical hurdles remain. One important hurdle is the ability to monitor the controlled differentiation of stem cells into the desired tissue type and to isolate pure populations of cells with the potential to form a single tissue type. While reporter constructs have been designed to facilitate this process, the resulting cells have limited potential for human therapeutics because the reporter either integrates into the cells’ genomic DNA, or exists in the cell’s cytoplasm indefinitely. To realize the potential of cell-based therapies for human disease, it is therefore imperative that methods are developed to monitor and isolate pure populations of live human stem cells without altering cellular properties.

 Invention:

Prominent UCSF scientists have developed a novel method to monitor and isolate live human embryonic stem cells (hESCs) based upon the expression of intracellular proteins. The method involves the design of dual fluoresce resonance energy transfer (FRET) molecular beacons to monitor the expression of specific proteins. Crucially, the beacons used do not alter the functional or genomic characteristics of hESCs. In a major innovative step, the team has adapted this FRET-based reporter system for a high-throughput fluorescence-activated cell sorting (FACS) apparatus. Therefore, not only can protein expression be analyzed using standard confocal microscopy techniques, but pure populations of cells expressing particular tissue-specific proteins can be isolated for clinical applications. To validate this approach, the team monitored the expression of Oct4 (a nuclear transcription factor associated with pluripotency) and successfully demonstrated that Oct-4 expressing hESCs could be isolated via FRET-based FACS. Importantly, FRET-positive hESCs demonstrated pluripotency in culture and in vivo, and molecular beacons are reliably shed from the cell after use.

File Number: 21073 

Web site: http://techtransfer.universityofcalifornia.edu/...

Other Information:

Publications

King et al., (2010) High throughput tracking of pluripotent human embryonic stem cells with dual FRET molecular beacons. Stem Cells and Development, epub ahead of print: http://www.liebertonline.com/doi/abs/10.1089/scd.2010.0219

This invention is available for licensing and the inventors welcome the opportunity to collaborate with industry partners.