`Training' Cells To Fight Cancer And Other Diseases

DENDRITIC CELLS ARE THE pacesetters of the human immune system--they regulate the activity of immune cells in lymph nodes. Now, these white blood cells may be harnessed as the building blocks for potent therapeutic cancer vaccines.

Researchers at the University of Pittsburgh Medical Center (UPMC) are "training" dendritic cells to target specific tumors afflicting individual patients. The researchers are able to do that by culturing the cells with synthetic peptides that mimic a protein from a patient's tumor. When the altered dendritic cells are then injected into the patient, they activate the T-cells and other disease fighters to attack tumor cells throughout the body. "Our goal is to create a less toxic and more effective therapy," says surgical oncologist Michael T. Lotze.

Limited human trials at Pittsburgh's Cancer Institute clearly show promise. In the most dramatic cases, melanoma tumors disappeared in two patients. In studies involving mice, dendritic cells trained with melanoma or lung carcinoma cells resulted in vaccines that prevented tumors from growing in healthy mice--and shrunk the tumors in 80% of mice with cancer.

UPMC recently received $10 million from the National Cancer Institute to expand its dendritic-cell research. Other Medical Center researchers hope dendritic cells can boost the immune system's response to HIV, the virus that causes AIDS, and human trials aimed at HIV are scheduled to begin this fall.