Natural killer cells (NK cells) are an important component of the innate immune system. They provide protection against viral and bacterial infections, and they help to detect and limit the development of cancer.
Now, researchers at New Zealand's University of Otago say they have found another role. The researchers' new work, published recently in the Journal of Immunology shows that NK cells act as helper cells to start up the immune response.
"Certain molecules act like identity cards, and NK cell are vigilantes, ready to respond if they don't see an ID card on cells. During infections or with cancer, the absence of these molecules triggers the NK cells to destroy the cells," says Otago associate professor Alexander McLellan, second author on the paper.
"A few years ago we showed that NK cells were required for the vaccination response against cancer. Our group has now recognized that NK cells enhance the ability of the immune system to recognize fragments of tumor cells released into the blood," adds McLellan. These fragments induce potent immune responses against cancer, he explains.
"Our new work shows that NK cells are absolutely critical for the immune activity of these cell fragments."
The group is currently looking at ways to improve NK cell function through living vaccines and growth factors to enhance the immune response to cancer.