Rescuing dendritic cell interstitial motility sustains antitumour immunity

Area of Science:

• Immunology
• Cancer Biology
• Cellular Motility

Background:

• Dendritic cell (DC) migration is crucial for initiating and sustaining anti-tumor T cell responses.
• Tumor progression often leads to decreased DC migration, impairing anti-tumor immunity.
• Understanding the mechanisms regulating DC migration is vital for developing effective cancer immunotherapies.

Purpose of the Study:

• To investigate the mechanisms underlying the decline of DC migration during tumor progression.
• To identify novel targets for enhancing DC migration and anti-tumor immunity.

Main Methods:

• Longitudinal analysis of human and mouse tumors.
• Genome-wide in vivo CRISPR screening.
• Pharmacological inhibition of phosphodiesterase 5 (PDE5) with sildenafil.

Main Results:

• A progressive decrease in migratory conventional DCs (mig-cDCs) in tumor-draining lymph nodes (tdLNs) was observed during tumor progression.
• Phosphodiesterase 5 (PDE5) and cyclic guanosine monophosphate (cGMP) were identified as key regulators of DC migration.
• Inhibition of PDE5 restored mig-cDC homing to tdLNs and enhanced anti-tumor immunity in a DC-dependent manner.

Conclusions:

• Disruption of cGMP synthesis in DCs by advanced tumors impairs their motility and promotes immune evasion.
• Enhancing DC migration through PDE5 inhibition offers a promising strategy for DC-centric cancer immunotherapy.
• This study links fundamental DC motility to anti-tumor immunity, highlighting a new therapeutic avenue.