U of A researchers and killer T-cells

By Jon Dunbar

Just four and a half months after University of Alberta researchers made headlines in international medical news, they’ve done it again.

U of A professors recently announced a breakthrough discovery in the workings of the body’s immune system, which has applications in treatment of cancer,
organ transplants and auto-immune diseases like diabetes and rheumatoid arthritis.

The team is led by Chris Bleackley, considered one of the world’s leading experts on the immune system’s treatment of infected cells. Other members are Bruce Motyka and Greg Korbutt.

Korbutt, an expert in cell transplants, played an important role in the diabetes research which attracted international attention in mid-May.

This latest discovery arose from research examining the cytotoxic T lymphocyte, or killer T-cell, which plays a significant role in ridding the body of viral cells.
For years, researchers were puzzled by how some cancerous cells are able to evade these killer cells. A normal, healthy cell has a surface receptor that allows the killer cells to bond to it, but the U of A researchers discovered that some tumour cells have the ability to remove these receptors and keep the killer cells out.

"We are looking at whether or not our killer molecule can bind to [cancer] cells," said Motyka. "Sometimes it’s called the kiss of death."

Through his research, Motyka hopes to learn how to improve the effectiveness of killer T-cells.

In laboratory transplants, the researchers found that without the receptors, the cells were allowed to live in foreign tissue–a finding that has significant relevance to organ-transplant procedures. Presently, between 50 to 60 per cent of organ transplants fail because the body rejects the foreign tissue.

Several years ago, Bleackley drew international attention when he discovered Granzyme B, the active enzyme in killer T-cells that destroys the unhealthy cells.
The findings of Bleackley’s team have been published in the current issue of the medical journal Cell.

"Our study is a basic research finding," said Motyka. "It’s still early, and a lot of experiments have to be done."

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