The constant battle against infectious pathogens has had a decisive influence on the human immune system over the course of our evolution. A key role in our adaptation to pathogens is played by HLA molecules. These proteins activate the immune system by presenting it with fragments of pathogens that have entered the body. People with a wide variety of different HLA proteins are thus better armed against a large number of pathogens. Researchers at the Max Planck Institute for Evolutionary Biology in Plön, Germany, together with colleagues in New York, have been investigating the diversity of HLA genes in cancer patients being treated with immune checkpoint inhibitors. This form of immunotherapy activates the body's own immune cells to enable them to identify and eliminate tumor cells. The researchers discovered that patients with a wide variety of HLA molecules derive more benefit from this type of therapy. This means that in future, doctors may be able to offer improved individual treatment based on a patient's HLA gene profile. In the evolution of an organism, the characteristics which often prevail are those which increase the chances of survival and reproduction of their carrier. In contrast, for a robust immune system it could be advantageous for it to be variable, keeping as many options open as possible - a hypothesis which has been tested and confirmed in an early study carried out specifically on HLA molecules by Fr. Federica Pierini and Dr. Tobias Lenz at the Max Planck Institute for Evolutionary Biology. It is therefore essential for the effectiveness of an immune system to have many different variants of HLA molecules, Because each variant can bind to several different pathogen or cancer cell protein fragments.Login Or Register To Read Full Story