I recently wrote a post about a clinical trial that freed a woman from her advanced cancer. Her treatment used her own white blood cells – specifically the white blood cells that were swarming her tumors (called “Tumor Infiltrating Lymphocytes (TILs)”).

A couple of people have since asked me how white blood cells actually work once they have found the cancer cells. It’s a good question, so I thought I’d write a short follow-up explanation on it here.

TILs kill cancer cells by disrupting the membrane of the cancer cells (a process called lysis), as well as by forcing the cancer to undergo programmed cell death (a process called apoptosis – to put it bluntly, it forces the cancer cell to commit suicide).

TILs are actually made up of a variety of different white blood cells, but the one that is particularly effective in treating the patient’s cancer is what’s called “cytotoxic CD8+ T-cells”.

When a T-cell bind to its target cancer cell, it releases a bunch of toxic chemicals that enters the cancer cell and causes lysis and apoptosis of the cancer.

So that’s the underlying mechanism for how TILs can kill cancer cells once they’ve attached themselves!