Researchers at Yale Cancer Center and Yale Medicine have identified the critical target of new immune-checkpoint therapies: subsets of immune cells called tissue resident memory (TRM) T cells.

In the same research, scientists also found that individual metastatic cancer lesions contain unique sets of TRM cells.

The results of the study are published in the issue of the Journal of Clinical Investigation Insights.

“Immune checkpoint therapies have begun to transform cancer therapy,” said the study’s senior author, Kavita M.

Dhodapkar, MD, Associate Professor of Paediatrics at Yale School of Medicine and Director of the Phase I Program in Pediatric Oncology at Smilow Cancer Hospital.

“This research shows that the specific immune subset expressing these inhibitory molecules is a distinct subset called tissue resident memory T cells.”

Tumour tissue resident memory T cells are different from T cells circulating in the blood, both at a phenotypic and genomic level.

“Each cancer lesion appears to carry a distinct set of these immune cells, meaning that the mechanism by which these immune therapies work (or fail) may differ in each of the lesions,” Dr Dhodapkar said.

“We believe that ability to generate T cells with characteristics of TRM T cells will be important in allowing tumour-specific T cells to hone to and persist within tumours,” said Dr Dhodapkar.

“Understanding the biology of TRM cells and the factors that control the persistence of these T cells within tumours will allow us to improve upon the current immune therapies.”

Source: Yale Cancer Center