Scientists have tried for decades to create vaccines that spur a cancer patient's immune system into attacking tumors, but cancer cells cleverly defuse the attack. Research in mice now suggests a new way to overcome these defenses and rally the immune system to action.
Previous attempts to defeat tumor defenses with a vaccine caused dangerous side effects by provoking the immune system to attack healthy cells indiscriminately. The new technique is the first with the potential to selectively bolster the immune system's attack on tumor cells while sparing healthy cells.
"This is not like inducing the whole immune response," says Xiao-Tong Song of the Baylor College of Medicine in Houston. Getting an immune response that's specific to tumor cells is difficult, Song explains. Tumors protect themselves by hijacking the immune system's own generic "stop" signals. Simply blocking these stop signals lets the immune system run out of control and attack any cell it finds.