Why Can’t The Immune System Fight Cancer All Alone?
Patients that have diagnosed cancers have cancer cells that have escaped immune detection.
This is because these cancer cells have been able to mask themselves so that by cell surface receptor, they resemble normal cells to the immune system.
Much of this has become apparent through research on check point inhibitors. Immune resistent cancer cells have PD-L1 surface markers that bind to PD-1 receptors on T cells which then “checks” the immune response against them.
Therapeutic antibodies developed and now FDA approved in many cancers (lung, kidney, head and neck, bladder with more to follow) work to unmask the cancer to the immune system by interupting the PD-L1 receptor. The immune response is unleashed and in some cases, very advanced cancers are destroyed completely.
The treatments frequently don’t work so that there is much more work to be done but it’s a thrilling start to treating cancer using our own immune systems.
Here’s a great illustration from Harvard’s Dana Farber Cancer Center.
