The findings open new avenues in which to further explore the function of regulatory T cells in autoimmune disease and in cancer, the researchers say.

For example, mice experiments show that if regulatory T cells are destroyed, the animals will develop arthritis and other autoimmune diseases. So, if scientists can determine precisely how Hassall's corpuscles and dendritic cells turn T cells into regulatory T cells, it may be possible to "convert" the errant T cells that promote an immune response in tissue into regulatory T cells, thus suppressing such disorders, Liu says.

Similarly, the discovery may help provide clues as to how cancer cells use regulatory T cells to work on their behalf, he says. One of the beneficial roles of regulatory T cells is to suppress the immune system (thus inactivating the damage caused by errant T cells), but "in cancer patients, regulatory T cells become troublemakers, because they suppress any natural reaction the immune system might have mounted to fight the cancer," Liu says.

"It may be that cancer is converting normal T cells into regulatory T cells to protect itself, and once we know the molecular language by which Hassall's corpuscles and dendritic cells induce regulatory T cells, then we might understand how tumor cells also do this," he says.

'"/>

Contact: Nancy Jensen
nwjensen@mdanderson.org
713-792-0655
University of Texas M. D. Anderson Cancer Center
11-Oct-2005