Daily body clock influences tumor immune suppression and response to immune checkpoint therapy

Circadian control influences the abundance of immunosuppressive cells, particularly PD-L1-expressing myeloid-derived suppressor cells (MDSCs), in colorectal cancer.

• The immune landscape is modulated by circadian rhythms, affecting host defense and tumor immunosurveillance.
• Single-cell RNA sequencing reveals clock-dependent changes impacting cytotoxic CD8T cell suppression.
• PD-L1-expressing MDSCs exhibit rhythmic peaks in abundance, suggesting a timed pattern of immunosuppression.
• Disruption of the epithelial cell clock leads to increased cytokine secretion, promoting inflammation and MDSC development.
• Timing of anti-PD-L1 treatment is more effective when aligned with MDSC abundance.

Simplified