Listeria, a type of bacteria that can cause life-threatening disease in humans, may be a life-saver in the fight against cancer. A version of the bacteria that do not cause disease turns out to be good at invading and killing cancer cells. In normal cells, the presence of bacteria triggers an alert to the immune system that halts infection, but cancer cells tend to suppress such immune signals. This immune suppression is beneficial to cancer cells under normal circumstances because it allows them to avoid detection. But in the case of listeria infection the lack of an immune reaction allows the bacteria (coloured red) to freely replicate and accumulate inside the cancer cells (shown with blue nuclei and green interiors), ultimately destroying them. And scientists have now made the bugs even more effective cancer killers, loading them with a radioactive payload for delivery right to the target cells.
Written by Ruth Williams
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