A way to make "tired" immune cells fight cancer has been found

Scientists from the Van Andel Institute have discovered a molecule that prevents the immune system from effectively fighting cancer. It's PTGIR - a receptor capable of weakening the activity of T-cells, key participants in the immune response. The research is published in the journal Nature Immunology (NatIm).

T-cells are a type of white blood cells whose task is to recognize and destroy infected or malignant cells. However, in conditions of prolonged battle with a tumor, they can become "exhausted," losing their ability to attack. Researchers have established that PTGIR contributes to this exhaustion: when its activity increases, T-cells produce fewer anti-tumor substances and become less effective.

Unlike already known immune checkpoints, which are based on protein interactions, PTGIR is activated by a lipid molecule - prostacyclin. This fat-like signal is often found in excess in the tumor environment, which makes PTGIR particularly active exactly where it interferes the most.

The research leader Russell Jones explains that behind PTGIR activation is another protein - NRF2. It essentially "hits the brakes" on the immune system, preventing T-cells from doing their job. If this mechanism can be blocked, the immune response could be "awakened" and directed against the tumor.

According to the first author of the article Michael Dahabi, the discovery of PTGIR could change the approach to immunotherapy. This pathway may be especially useful for patients whose cancer does not respond to existing treatment methods. It is suggested that PTGIR blockers could become a new type of anti-tumor drugs or be used as part of combination therapy.