Cancer, AIDS hope from stem cell study

Melbourne, Australia (CNN) -- A breakthrough in stem cell research in Australia could hold a key to the treatment of cancers, AIDS and other auto-immune diseases.

A team from the Monash University Medical School in Melbourne, Victoria, have identified and grown stem cells to regenerate the thymus -- a crucial organ in a human's immune system.

The thymus produces many of the cells that make up the body's immune system, including the infection-fighting T-cells.

Stem cells are cells which can be manipulated by scientists to grow into specific parts of a body.

While the Australian scientists have only managed to grow a mouse's thymus so far, they believe a human thymus could be produced from stem cells in three to five years.

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"We are very confident this will work," Dr Jason Gill told CNN. "The mouse models translate very well to human cells."

"This has a lot of potential and we are very excited for the future."

But Gill warned treatments for conditions related to the human immune system -- such as HIV/AIDS -- that might develop from this research could be at least 10 years away.

Puberty

Apart from potentially being able to treat or regrow an ailing thymus, Gill says the better understanding of how the thymus and immune system cells works will most likely lead to better disease treatments.

Up until now, it had not been known which cells lead to the creation of the crucial epithelium part of the thymus.

The epithelium converts other stem cells into T-cells. It also controls the ability of T-cells to recognize invaders in the body and helps prevent T-cells from attacking healthy body tissues.

But thymus activity reduces after puberty.

The Monash research could lead to the discovery of how the thymus can be stimulated to renew the production of immune system cells.

This could lead to treatments for conditions where T-cells have been depleted, such as AIDS, and after chemotherapy.

Further research

New treatments for auto-immune conditions could be developed from Australian research

The Monash team has isolated a population of epithelium stem cell markers in a mouse thymus and proved that they can be grown into a fully functioning thymus.

The next part of the research will be identifying and isolating epithelium stem cells from a human thymus.

Gill said such stem cells were theorized to be present in humans and he would be very surprised if they were not there and accessible at the cell surface, as they are in a mouse thymus.

The team's findings -- the outcome of 15 years' research -- were published Tuesday in the respected Nature Immunology journal.

Researchers at Monash University in the southern State of Victoria are amongst the world leaders in many fields of stem cell research -- a leadership which has developed out of earlier pioneering work in in-vitro fertilization.