Mountain climbers and endurance athletes are not the only ones to benefit from altitude training – that is, learning to perform well under low-oxygen conditions. It turns out that cancer-fighting cells of the immune system can also improve their performance through a cellular version of such a regimen. In a study published in Cell Reports, Weizmann Institute of Science researchers have shown that immune system’s killer T cells destroy cancerous tumors much more effectively after being starved for oxygen.
Mountain climbers and endurance athletes are not the only ones to benefit from altitude training – that is, learning to perform well under low-oxygen conditions. It turns out that cancer-fighting cells of the immune system can also improve their performance through a cellular version of such a regimen. In a study published in Cell Reports, Weizmann Institute of Science researchers have shown that immune system’s killer T cells destroy cancerous tumors much more effectively after being starved for oxygen.
Harnessing the immune system to battle malignancy – an approach known as cancer immunotherapy – has already started saving the lives of cancer patients in the past few years. In one major version of this approach, killer T cells are removed from the patient’s blood, grown in a laboratory dish and adapted to identifying and destroying cancerous cells; they are then returned to the patient’s bloodstream. This method has so far worked best against certain leukemias and lymphomas, but not against solid tumors, possibly because within such tumors, oxygen concentration is extremely low: 0.5% to 5% of the gas dissolved in the extracellular fluid – lower than in most healthy organs, and certainly much lower compared with a regular lab incubator, in which oxygen accounts for 20% of the gas dissolved in the culture fluid used for growing the cells.
Tumor cells don’t seem to mind the shortage; they manage to make effective use of glucose, the major cellular fuel, even when oxygen concentration is low. But the same is not true for T cells, which have a hard time penetrating tumors and performing their killing function. Previous studies had shown that growing T cells under low-oxygen conditions helps them kill other cells in a laboratory dish, but their actual cancer-fighting ability has never been tested.
Read more at Weizmann Institute of Science
Image: Cancerous tumor tissue under a microscope: T cells grown under low oxygen conditions (green) and regular T cells (purple) show similar distribution patterns vis-à-vis blood vessels (red). Right: The content of granzyme B, a cell-killing enzyme (red), is much higher in T cells grown under low oxygen conditions (top) than in regular T cells (bottom). (Credit: Weizmann Institute of Science)
