Cognate Nonlytic Interactions between CD8 T Cells and Breast Cancer Cells Induce Cancer Stem Cell-like Properties.

Targeting of tumor immune escape mechanisms holds enormous therapeutic potential. Still, most patients progress under immune checkpoint blockade and some even become hyperprogressors. To investigate how cancer cells respond to activated but ineffective T cells, we challenged peptide-loaded MCF-7 breast cancer cells with antigen-specific CD8 T cells in which lytic granules had been destroyed by pretreatment with Concanamycin A.