We’ve made some impressive advances toward inducing the immune system to attack cancers. One of these techniques, using CAR-T cells, is amazing. CAR-T cells are made by inserting receptors that recognize cancerous cells into a leukemia patient’s own T cells. This induces those T cells to recognize the patient’s tumor as the threat that it is and destroy it.
But, that T cells mount such an effective immune response is their therapeutic weakness as well as their strength. Engineered immune cells like these can completely disrupt normal immune function, causing unpleasant conditions with names like macrophage activating syndrome, cytokine storms, and even neurotoxicity, all of which can be life-threatening. So a group of Swiss researchers has decided to engineer a killing system into non-immune cells to avoid all these side effects.
T cells target their tumor-killing immune response through cell-to-cell contact. This is a distinctive feature of how the T cell receptor works. It hangs out on the T cell’s surface membrane, with some parts on the outside and some parts on the inside. When its external part contacts a particular feature on the surface of a cell, its intracellular part sends a signal through a cascade of molecules that eventually results in collection genes getting expressed. These genes include the ones needed to kill the target cell.