Abstract
Expression of inhibitory receptors (iRs), such as CTLA-4 and PD-1, are associated with impaired immune cell function and can limit anti-tumour immune responses. Therapies that block inhibitory receptors (immune checkpoint blockade, ICB) can enhance the anti-tumour immune response and improve patient survival. A high infiltrate of iR+ T cells are present in the tumours of patients with colorectal cancer (CRC); however, ICB is not effective in many CRC patients.
The aims of this study were to determine iR expression on T cells in CRC and associate iR expression on T cells with T cell functionality ex vivo and in vitro. We hypothesised that expression of iRs does not correlate with impaired immune cell function and iR+ T cells are important in the anti-tumour immune response.