ALTERNATIVE TO SCR

Scientists Reprogram Cells Without Human Cloning

Washington, DC -- Scientists said on Tuesday they had transformed ordinary human skin cells into immune cells in an experiment that, if it can be repeated, might do away with the need for either stem cells or cloning for many medical therapies.

The team at biotech start-up Nucleotech LLC hope to be able to offer patients grow-your-own transplants that could theoretically be used to treat diseases such as immune deficiencies and juvenile diabetes.

Many teams are working on the idea, but nearly all had assumed the need for stem cells, the body's master cells, which are elusive and difficult to grow in the lab.

Such stem cells could also theoretically be made using cloning technology -- something highly controversial and the subject of competing legislation in the U.S. Congress. President George W. Bush supports a complete ban on the use of cloning technology involving humans.

But James Robl, Philippe Collas and colleagues at Nucleotech and the University of Oslo believe they have found a way around the controversy.

By punching holes in mature skin cells and soaking them in a solution made from immune system cells, they said they turned them into what look like T-cells -- key immune system cells.

``They start acting like T-cells,'' Collas told Reuters. ``That's the beauty of our system -- we are not working with embryos or dealing with stem cells at all. You get around all these issues.''

Robl, a leading stem cell researcher who left the academic world to work for biotechnology companies, wants to use the approach to transform medicine.

``It would be a one-day procedure, in principal,'' he said. ``The patient would come in and give a skin biopsy to the lab to reprogram and the day after you could put the cells back into the patient.''

Researchers working with stem cells have had a similar idea for treating diabetes, by making pancreatic cells, for treating Parkinson's or Alzheimer's by making new brain cells and for treating spinal cord injuries by making new nerve cells.

IMMEDIATE APPLICATIONS IN CANCER

Making T-cells could have immediate applications in treating cancer, said Collas, who led the study.

``Advanced cancer patients often have low T-cell counts,'' he said. ``If you took a skin cell from a patient and turned it into a T-cell in the presence of tumor antigens, you could expand a T-cell population that in theory would respond to the tumor.''

The company was also looking at making pancreatic islet cells -- the cells that make insulin and which are destroyed in juvenile or type-I diabetes, Robl added.

Writing in the journal Nature Biotechnology, the team said they first made the skin cells permeable by punching tiny pores in the cell walls. They then grew them in a solution containing extracts from T-cells.

The new cells stopped expressing the genes that skin cells express -- meaning they stopped functioning like skin cells, and instead turned on genes usually active only in immune cells, such as IL2, IL7, CD3, CD4 and RANTES.

``In effect you are washing regulatory factors out from inside the cell and replacing them,'' Robl said.

Instead of harnessing an early stem cell whose genes have not yet been all turned on, the team completely changed the cell's environment and thus changed the cell's function.