"Our findings suggest a potentially important design principle for vaccines and challenge the prevailing theory used for vaccine design," said Christopher C. Norbury, Ph.D., assistant professor of microbiology and immunology, Penn State College of Medicine, Penn State Milton S. Hershey Medical Center. "Ultimately, our information suggests that vaccines should target both pathways that generate T cells, which are our killer cells, to allow the most efficient protection against viruses."
The study, conducted by Penn State College of Medicine and National Institutes of Health investigators and titled, "CD8+ T Cell Cross-Priming via Transfer of Proteasome Substrates," was published May 28, 2004, in the journal Science.
Some viruses, like chickenpox, travel outside of cells in the body's bloodstream. When introduced to the body, these viruses trigger antibodies that destroy the virus. For example, the chickenpox vaccine contains dead virus that, when administered, trains the body to recognize and create antibodies to kill the virus. The body is then prepared to react if exposed to live virus.
However, some viruses, like human immunodeficiency virus (HIV) and smallpox, travel inside cells where antibodies cannot penetrate. These viruses are transferred from cell to cell and only specialized white blood cells called T cells, which can penetrate cell walls, can kill them.
"There's a great deal of research going into the design of vaccines to target these types of difficult-to-destroy viruses," Norbury said. "Most focus on how to boost or improve the body's own T cell response to the virus."
CD8+ T cells play an important role in the elimination of tumor cells and disease-causing agents such as viruses. For the T cells to r
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Contact: Valerie Gliem
vgliem@psu.edu
814-865-9481
Penn State
27-May-2004