Exhausted T cells can provide long-lasting cancer immunity in mice

Researchers at the University of Pittsburgh School of Medicine have discovered that certain exhausted T cells can provide long-lasting immunity against cancer in mice. The study, published in the Journal of Experimental Medicine, challenges the previous assumption that T cells expressing the exhaustion marker LAG3 are non-functional or destined to die within a tumor.

Using a new mouse model involving tamoxifen to trigger a permanent red fluorescent protein (tdTomato) in LAG3-expressing cells, the team tracked the movement of these cells. They found that a subset of these cells eventually stopped expressing LAG3 and migrated out of the tumor to lymph nodes and other tissues. These cells were found to drive long-lasting immune memory, offering potential implications for the development of LAG3-targeting cancer immunotherapies.