Their work appears in an upcoming issue of the Proceedings of the National Academy of Sciences and is currently available online.

"We have been applying new technology to an old problem: How do cells of the immune system recognize and deal with infected cells and other cells, such as tumor cells, that would be harmful to the well-being of the organism?" said Dr. John Schatzle, assistant professor of pathology and senior author of the study.

The immune system uses natural killer (NK) cells and cytotoxic T cells to help eliminate viral infections and cancer cells, said Dr. Christoph Wuelfing, assistant professor in the Center for Immunology and the study's lead author.

UT Southwestern researchers used three-dimensional microscopy in real-time to visualize the subcellular localization of components of NK cells during the in vitro killing of tumor target cells. By learning that cellular organization has to go through a defined series of steps to kill a target cell, researchers now can study how these cells function, said Dr. Wuelfing.

Specifically, the researchers examined the NK cell cytoskeleton (the part of each cell primarily responsible for the spatial organization of its components) during target cell killing in comparison to that of cytotoxic T cells. Both of these immune system cells release toxic molecules through a highly regulated process controlled by receptors attached to them.

The cells, however, differ in their roles and the types of receptors they use to recognize cells to be eliminated, Dr. Schatzle said. The NK cells represent effectors of the innate immune response and constitute a first line of defense against infection and tumors. The cytotox
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Contact: Scott Maier
scott.maier@utsouthwestern.edu
214-648-3404
UT Southwestern Medical Center
9-Jun-2003