TcdB Based Protein Delivery of iPSC Reprogramming Factors

Award Information
Agency: Department of Health and Human Services
Branch: N/A
Contract: 1R43GM093530-01A1
Agency Tracking Number: R43GM093530
Amount: $324,516.00
Phase: Phase I
Program: SBIR
Awards Year: 2011
Solicitation Year: 2011
Solicitation Topic Code: NIGMS
Solicitation Number: PA10-050
Small Business Information
1448 S Rolling Road, BALTIMORE, MD, 21227-
DUNS: 791107563
HUBZone Owned: N
Woman Owned: N
Socially and Economically Disadvantaged: N
Principal Investigator
 (301) 987-0480
Business Contact
Phone: (443) 543-5890
Research Institution
DESCRIPTION (provided by applicant): Induced pluripotent stem cells (iPSC) have tremendous potential for regenerative medicine in future. However, there are obstacles to overcome before the iPSC can be used therapeutically. One major hurdle is the tool used to generate iPSC from adult somatic cells. We believe that the delivery of reprogramming proteins directly rather than the genes that encode these proteins is the safest means for generating iPSC. We propose to engineer Clostridium difficile toxin TcdB as a cytosolic delivery vehicle for embryonic transactivators that can reprogram adult somatic cells to induced pluripotent stem cells (iPSC) and/or tissue specific cells. C. difficile toxin TcdB, exhibits multiple modular domains that provide all the mechanisms that allow the toxin efficiently deliver its N-terminal enzymatic domain (GT domain) to cytosol. We will engineer TcdB as a universal protein delivery vehicle by replaceing the enzymatic domain with a protein cargo to provide therapeutic benefits.We will initially append a chimeric transacivator to the N-terminus of the toxin or replace the GT domain with the chimeric transactivator. Using a high-throughput reporter cell line system, we will first examine how effectively the engineered recombinantprotein can deliver a biologically active cargo. We will then test if the engineered TcdB can deliver biologically active reprogramming factors (Oct4 and Sox2) to another reporter cell line and assess their ability to differentiate mouse embryonic stem cells with the help of our collaborators. Finally, we will use the TcdB delivery vehicle to generate of iPSC from mouse embryonic fibroblasts after we demonstrate that we can deliver those reprogramming factors efficiently to the well-characterized reportercells. Other methods of delivering proteins, such as the TAT protein transduction domain, will be tested in parallel to compare the efficiency of our novel system to established techniques. We believe this TcdB-based protein delivery vehicle will be a valuable tool for generating iPSC for research purposes, drug development, and toxicology studies. We also anticipate the development of TcdB-based biologics for regenerative medicine. PUBLIC HEALTH RELEVANCE: This project will investigate the use of anew protein delivery vehicle to introduce reprogramming factors to adult skin cells in order to convert them to induced pluripotent stem cells (iPSC). This approach relies on proteins rather than genes to create iPSC, which avoids the potential dangers ofgenetic modification. These iPSC have enormous potential to replace embryonic stem cells for regenerative medicine.

* Information listed above is at the time of submission. *

Agency Micro-sites

SBA logo
Department of Agriculture logo
Department of Commerce logo
Department of Defense logo
Department of Education logo
Department of Energy logo
Department of Health and Human Services logo
Department of Homeland Security logo
Department of Transportation logo
Environmental Protection Agency logo
National Aeronautics and Space Administration logo
National Science Foundation logo
US Flag An Official Website of the United States Government