"Conventional thinking and previous studies suggest that the tumor environment is responsible for immune dysfunction in cancer-fighting T lymphocytes that congregate at the site of a tumor. The major unresolved question is the origin and mechanism responsible for immune dysfunction in tumor-infiltrating T cells. We found that damaged T cells arose from a particular cell lineage, within a tumor environment that lacks factors promoting their survival," said Keith L. Black, MD, director of Cedars-Sinai's Maxine Dunitz Neurosurgical Institute, where the mouse studies were conducted. "Furthermore, we were able to influence the cells in a way that decreased the number of dysfunctional cells, a finding that we hope may eventually lead to more effective vaccine therapies against established tumors."
In a localized immune response, T cells are mobilized to attack cells that the immune system recognizes as invaders. Because specific lymphocytes recognize and attack specific immune threats, they are called "antigen-specific." In cancer vaccine experiments, such as those ongoing at the Institute to improve treatment for brain tumors, researchers seek to improve the immune response by helping cancer-fighting cells identify tumor cells as potential targets.
T cell activation is considered a major defense mechanism in the prevention of tumor formation, and in rodent studies T cell responses have been able to eradicate recently established tumors. In both humans and animals,
Contact: Sandra Van
Cedars-Sinai Medical Center