Medical Discovery News: Advances in T cell therapy may fight cancer without side effects

Drs. Norbert Herzog and David Niesel
Medical Discovery News

The human immune system is truly a wonder. It plays a critical role in our body’s defense to invading disease. Like a home security system, it is on alert 24/7/365. Through multiple mechanisms, it guards all our tissues, protects us from microbial foreign invaders, and removes cancer cells to keep us disease-free. For example, B cells are responsible for the production of antibody proteins. These proteins recognize and target specific invaders, which are then removed by other cells. Another type of immune cell, called T cells, can directly interact with and kill foreign invaders and help orchestrate other elements of the “host response” that protects us.

Medical Discovery News

New therapies for cancer have focused on activating and enhancing the immune system, specifically T cells. One approach is to engineer T cells to recognize and kill cancer cells through a protein called a chimeric antigen receptor (CAR). In this therapy, scientists take T cells from a patient’s blood and manipulate them in the laboratory so that they attack the patient’s cancer cells. The scientists program the T cells to attack cancer cells by adding a gene that produces this CAR protein. The CAR protein helps the T cells recognize and kill cancer cells. Scientists grow large numbers of these cells in the laboratory and infuse them into the patient, providing millions of T cells dedicated to removing the cancer cells. These CAR T cells will stay in the body and continue to fight the cancer. CAR T cell therapy is the ultimate in personalized cancer therapy designed precisely for the person’s individual cancer.

Unfortunately, there can be side effects of the CAR-T therapy. After receiving the infusion of these modified T cells, patients can develop cytokine release syndrome, which is a serious overreaction of the immune system that causes symptoms like chills, fatigue and low blood pressure. Neurotoxicity is also possible, with patients showing symptoms like confusion, shaking, seizures and loss of speech. These are serious concerns that can be life-threatening.

New research may provide the same precision and personalization of CAR-T without the concerning side effects. Researchers engineered two different types of human non-immune cells, and they added a receptor that recognizes cancer cells. When these cells interact with cancer cells, it stimulates cellular reactions that produce a specific protein. The protein is transferred to surrounding cancer cells, which activates a drug given to the patient during treatment. The cancer cells are then killed by the activated drug.

More:Medical Discovery News: Vaping may lead teens to tobacco use

More:Medical Discovery News: Correct your vision with a smartphone with a laser, Nano-Drops

More:Medical Discovery News: New drug shrinks fat without affecting appetite

This type of treatment means a single synthetic T cell can lead to the destruction of many cancer cells. This provides two benefits. First, only cells in the immediate vicinity are killed, which limits surrounding tissue damage. Also, these synthetic T cells do not cause cytokine release syndrome, reducing adverse reactions to the therapy.

While this appears to represent a major step forward in CAR therapy, this approach needs to move from laboratory cell culture models to animal testing. This will validate the synthetic T cell treatment so that it can be safely evaluated in humans. We could someday see this therapy in clinics as a treatment for multiple forms of cancer.
