(News Medical Net) — A Ludwig Cancer Research study has uncovered a cellular interaction that is essential to the ability of the immune system’s cytotoxic T lymphocytes to destroy ovarian tumors and shown that its engagement could help determine the efficacy of checkpoint blockade immunotherapy in a variety of cancers.
The study, led by Ludwig Lausanne Director George Coukos and published in the current issue of Cancer Cell, describes how infiltrating T lymphocytes (TILs) that are best able to kill cancer cells reside in islets within ovarian tumors. These islets additionally house immune cells known as antigen presenting cells (APCs).
Coukos and his team show in cell culture and mouse experiments that the APCs, which help direct TILs to cancer cells and support their activity, stimulate a protein known as CD28 on TILs to boost and sustain their functionality. When treated with anti-PD-1 checkpoint blockade antibodies-;which disengage brakes imposed on TIL function-;it is this interaction that “licenses” TILs to destroy tumor cells. (…)