Using artificial antigen presenting cells, or aAPCs, the scientists converted run-of-the-mill immune cells into a horde of specific, targeted invader-fighting machines, they report in the advance online version of Nature Medicine on April 21.

"The ability to make vast quantities of targeted, antigen-specific immune cells in the lab broadens their potential in tackling a wide array of diseases, especially cancers," says Jonathan Schneck, Ph.D., professor of pathology and medicine at the Johns Hopkins School of Medicine. "Our technique provides an off-the-shelf way to create these cells."

The immune system normally defends the body against invaders. However, in cancer, tumor cells aren't recognized as "foreign," and after bone marrow and organ transplant the immune system has to be suppressed to avoid rejection of the transplant, opening the door to viral infections. Specially targeted immune cells that fill these defensive gaps are already being tested as experimental "cancer vaccines" in patients with melanoma and multiple myeloma and as virus fighters after bone marrow transplant.

However, the technological advance reported by the Johns Hopkins team overcomes a major weakness of current methods for making these targeted immune cells, known as antigen-specific cytotoxic T cells (CTLs) -- namely the methods' reliance on a patient's own dendritic cells. Dendritic cells are immune system sentries that wave the proteins, or antigens, of foreign invaders like flags, teaching immune system T cells to recognize the invading cells and kill them.

"But dendritic cells vary in quality and number from patient to patient," says first author Mathias Oelke, Ph.D., a postdoctoral fellow in pathology at Johns Hopkins. "Man
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Contact: Joanna Downer
jdowner1@jhmi.edu
410-614-5105
Johns Hopkins Medical Institutions
22-Apr-2003