A novel research highlights that highly specialized immune cells, called natural killer cells, play critical important role in killing melanoma cells that have spread to the lungs. As reported,  these natural killer cells could be harnessed to hunt down and kill cancers that have spread in the body.

The discoveries come after investigators showed that a protein called MCL-1 was crucial for survival of natural killer cells, in research appearing in the August 24th journal of Nature communication. And the discoveries will help to determine how natural killer cells can be manipulated to fight cancers.

MCL-1 levels inside the cell increase in response to a blood cell signalling protein called interleukin 15 (IL-15). As known previously, IL-15 increasing production was associated with survival of natural killer cells. This current research shows that IL-15 does this by initiating a cascade of signals that tell the natural killer cell to produce MCL-1 to keep it alive.

Investigators speculate that MCL-1 could be a target for boosting or depleting natural killer cell populations to treat disease, based on the discovery that the molecule is absolutely essential for keeping natural killer cells alive.

Natural killer cells are immune predators, patrolling the body in search of foreign invaders, and sensing changes in our own cells that are associated with cancer. Without these cells, the body was unable to destroy melanoma metastases that had spread throughout the body, and the cancers overwhelmed the lungs.

However these predatory natural killer cells are a double-edged sword. Investigators find natural killer cells were critical to the body’s rejection of donor bone marrow transplants and in the runaway immune response during toxic shock syndrome.

Reference:Innate immunodeficiency following genetic ablation of Mcl1 in natural killer cells. Nature Communications, 2014; 5