UCLA researchers have identified and analyzed the steps by which immune cells “see” and respond to cancer cells, providing insights into reasons some treatments may be effective for certain patients but not others.

According to the UCLA Jonsson Comprehensive Cancer Center scientists who led the research, the findings could lead to better, more personalized immunotherapies — even for patients whose immune systems currently do not appear to respond to treatment. The findings are published in Nature.

“This is an important step forward in our understanding of what the T-cell responses ‘see’ in the tumor and how they change over time in the tumor and in circulation in the blood,” said Cristina Puig-Saus, a researcher at the Jonsson Cancer Center and the first author of the study. “The deeper understanding of how the T-cell responses clear metastatic tumor masses will help us design better treatments and engineer T cells in multiple ways to mimic them.” 

The researchers adapted advanced gene-editing technology to make unprecedented observations of immune responses in people with metastatic melanoma who were undergoing anti-PD-1 checkpoint inhibitor immunotherapy. Although immune cells called T cells have the ability to detect mutations in cancer cells and eliminate them — leaving normal cells unharmed — cancer cells often evade the immune system. Checkpoint inhibitors are designed to improve T cells’ ability to recognize and attack cancer cells.

Read the full news release on the UCLA Health website.