Great article on the promise of immunotherapy in cancer treatment.
Click here to read the article from the Wall Street Journal.
An Innovative Approach to Cancer
T cells are the warriors of the immune system, responsible for hunting down and destroying infected or abnormal cells in the body. But the immune system also has natural brakes, which can prevent an effective T cell attack. Researchers are developing strategies to override that process in cancer. One approach: blocking a molecule called CTLA-4.
Turn the Ignition Key
Many tumors produce a substance called antigen, a protein recognized by the immune system. Cells known as antigen presenting cells capture antigens and present them to the T cells, starting an immune response.
Step on the Gas
For the T cell to be activated, a second interaction is needed. This may come from the binding of a molecule called CD28 on the T cell with another molecule called B7 on the antigen presenting cell.
Hit the Brakes
The immune system has natural brakes preventing it from going out of control. One brake, called CTLA-4, can bind to B7 in place of CD28, blocking that second signal and preventing activation of the T cell.
Release the Brakes
To override CTLA-4, the antibody-drug Yervoy blocks the CTLA-4 brake, restoring the second signal and activating the T cell.
Attack the Cancer
The activated T cell is now primed to see the antigen on the tumor cell and can mount an attack.
Sources: Dr. Charles Drake, Johns Hopkins Kimmel Cancer Center; Dr. Jedd Wolchok, Memorial Sloan Kettering Cancer Center; Bristol-Myers Squibb