Immune cells are always patrolling our intestines, even when we are healthy. This includes B cells, which produce antibodies. Antibodies are floating molecular fire extinguishers which bind to and neutralize infections. In our intestines, huge amounts of antibodies are made every day. These bind to the ‘friendly’ bacteria that we live with to make sure they are well balanced, which keeps us healthy. In inflammatory bowel disease (IBD), the intestine becomes damaged by the immune system and antibodies change which bacteria they bind to. This turns the population of gut-bacteria from friendly to harmful, and can cause IBD to become colorectal cancer.
We do not know which B cells make cancer antibodies, or how antibodies make bacteria harmful. To understand this, we need to know how dangerous B cells become selected to produce the antibodies that turn IBD into cancer. This requires special tools to tell the helpful cells apart from the harmful ones. We built mice with multicolored B cells so we can follow the B cells that become hijacked during IBD and cancer. We may then understand where cancer-causing antibodies are made, and what they bind to. By doing this, we hope to compile a list of common antibodies that are always made before IBD becomes cancer, and look for them as warning signs in IBD patients. This could give doctors more time to treat high-risk patients before tumors form. In the future, we hope our findings help design new cancer drugs to delete harmful B cells.
