Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Combined stem cell-gene therapy approach seen as potential treatment for cystic fibrosis

21.12.2004


Patients with cystic fibrosis (CF) could potentially be treated using their own stem cells that have been manipulated by gene therapy, suggests a study reported in this week’s Proceedings of the National Academy of Sciences (PNAS). The authors, who represent five institutions, including the University of Pittsburgh School of Medicine and Children’s Hospital of Pittsburgh, demonstrate for the first time that human bone marrow-derived adult stem cells can be coaxed to differentiate into airway epithelial cells and that encoding these cells with the gene that is defective in CF restores an important cellular function essential for keeping the airways clear of mucus and air-borne irritants.



"Our results provide proof of principle that a cell-based therapy using marrow stromal stem cells is both a feasible and promising clinical approach. We plan to further investigate its potential and are hopeful that we can perform a small clinical trial within the next two to three years," noted senior author Jay K. Kolls, M.D., professor of pediatrics, immunology and molecular genetics and biochemistry at the University of Pittsburgh School of Medicine and chief, Division of Pediatric Pulmonology and Laboratory of Lung Immunolgy and Host Defense at Children’s Hospital of Pittsburgh.

CF is the most common, fatal genetic disorder affecting Caucasians and is characterized by a mutation of a gene that sits on the surface of epithelial cells, including those that line the airways in the lungs. The gene, transmembrane conductance regulator (CFTR), is responsible for channeling chloride out of cells, an essential function that influences the level of airway surface liquid. This fluid sits atop the airway cells and provides support for the hair-like projections called cilia that sweep mucus and dirt away from the cell. When the level of liquid is too low, as is the case in CF, mucus builds up and the area becomes an attractive environment for bacteria to colonize and cause infection.


Finding ways to correct the gene defect responsible for CF has been the focus of much research and some clinical studies are even looking at gene therapy approaches. To date, no studies have evaluated the potential of adult stem cells or the use of stem cells in combination with ex vivo gene therapy, whereby the CFTR gene is delivered to the cells in a laboratory setting before their introduction into the patient.

While some studies have suggested the potential for bone marrow derived stem cells to differentiate into airway epithelial cells, Dr. Kolls and his co-authors have provided significant proof. Using a method they developed and report in PNAS, stem cells taken from normal subjects and placed in a culture with mature epithelial cells for 14 days differentiated into the specialized cells, taking on their shape and displaying their characteristic protein markers. Importantly, stem cells aspirated from the bone marrow of three CF patients and co-cultured in the same manner also produced airway epithelial cells, but, as expected, were deficient for the CFTR gene. To correct the genetic flaw, the researchers used the Maloney murine leukemia virus as a vector to shuttle the CFTR gene into the stem cells.

A technique called polymerase chain reaction, or PCR, confirmed the gene was expressed in the newly differentiated airway epithelial cells, reported Guoshun Wang, M.D., D.D.M, of Louisiana State University (LSU), where Dr. Kolls previously had worked, and Bruce A. Bunnell, Ph.D, of Tulane University, the study’s first authors. Moreover, the gene therapy-treated cells from CF patients had the same developmental potential as bone marrow-derived stem cells from healthy people.

To determine whether the gene therapy actually corrected the CFTR defect, the researchers exposed the cells to a medium containing labeled chloride and a molecule that regulates the intake and secretion of salts and water necessary for cellular function. If the CFTR gene were not functioning properly, the chloride taken in by the cell would not be able to be secreted. Yet, as the authors reported, the CFTR-corrected stem cells secreted significantly more chloride than stem cells from CF patients without the inserted gene.

"Being able to demonstrate that the gene permitted enhanced chloride channeling was critical to determining the potential of the stem cell-based therapy in the clinical setting," said Dr. Kolls.

Although he acknowledges that more work needs to be conducted, including developing a way to identify the specific subpopulation of bone marrow stem cells that are key to successful engraftment, Dr. Kolls is optimistic about the possibility that a patient’s own stem cells – which would not be subject to immune system attack – could be manipulated by gene therapy and used successfully as a treatment for CF. The ex vivo approach to gene therapy may offer several advantages, including the ability to screen the cells before actually delivering them to patients. In addition, the virus vector being studied by Dr. Kolls is bigger than others being used in trials and has the capacity for both the gene and its accessory apparatus, which may help ensure long-term function.

To further study the potential of the stem cell approach, including in CF patients, Dr. Kolls and colleagues from Children’s Hospital, in collaboration with the University of Pittsburgh, are seeking funding from the National Institutes of Health (NIH) to establish a center focusing on the development of adult stem cell-based therapies for diseases affecting the lung, heart and blood vessels.

In addition to Drs. Kolls, Wang and Bunnell, other authors of the PNAS study include Richard G. Painter, Ph.D., Nicholas A. Lanson, Jr., Ph.D., and Donna Bertucci, from LSU; Blesilda C. Quiniones, M.D., Susan Tom, Jeffrey L. Spees, Ph.D., Alexandra Peister, Ph.D., and Darwin J. Prockop, M.D., Ph.D., from Tulane; Daniel J. Weiss, M.D., Ph.D., of the University of Vermont College of Medicine; and Vincent G. Valentine, M.D., of the Ochsner Clinic Foundation in New Orleans.

Lisa Rossi | EurekAlert!
Further information:
http://www.upmc.edu
http://www.chp.edu

More articles from Life Sciences:

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>