Science Bytes: The Ninjas inside Us

Scanning electron microscope image of lymphoma cells dividing. Credit: Steve Gschmeissner Getty Images

There are tiny ninjas inside each of us. But you need not fear – they are reason why we are able to function normally most of the time. Known as Natural killer or NK cells and Gamma delta T-cells, they are the elite assassins among the soldiers that fight disease from within. They have the ability to swiftly locate and kill intruders that threaten the body such as different forms of tumor cells, including cancer cells. Unfortunately, they are not always successful. In some cancer patients, the defenses provided by these “ninja” cells are not working well, or the tumor is growing too fast, so the disease proliferates.

NK and gamma delta T-cells are part of our innate immunity. Innate immunity is our body’s first line of defense against infection and cancer. Around 10 percent of the lymphocytes (specialized white-blood cells) in our peripheral bloodstream are part of the innate response. 95 percent of those are natural killer (NK) cells, while a small minority of T-cells are specialized gamma delta T-cells.  As mentioned, each of these innate killer cells can recognize, target and kill harmful cells or “stressed” cells like tumor and virally-infected cells.

There is also an adaptive immunity within our bodies that work alongside our innate immune system. Adaptive immunity is antigen-specific, whereas the innate system is relatively nonspecific and can provide a rapid response. While earlier immunotherapy cancer research was directed at adaptive immunity, scientists are focusing on efforts to bolster the body’s innate immunity. One approach being explored is to combine the arsenal of both NK and gamma delta T-cells and grow them in large quantities so that the body can be flooded with an immune army to fight cancer.  Watch this space.

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