Death-associated protein kinase 1 (DAPK1) controls CD8⁺ T cell activation, trafficking, and antitumor activity

Area of Science:

• Immunology
• Molecular Biology
• Cancer Research

Background:

• Cytotoxic T cell migration into tumors is vital for antitumor immunity.
• The PI3K-Akt pathway's role in CD8+ T cell mTORC1 activation and trafficking is under investigation.
• T-cell receptor (TCR) signaling activates calcineurin, which in turn activates DAPK1.

Purpose of the Study:

• To investigate the role of DAPK1 in regulating CD8+ T cell trafficking into tumors.
• To determine if DAPK1-mTORC1 signaling influences CD8+ T cell migration and antitumor function.

Main Methods:

• Pharmacological inhibition of DAPK1 activity.
• Genetic approaches including deletion of DAPK1 kinase and death domains.
• Analysis of homing receptor expression (CD62L, CCR7).
• Assessment of T cell activation and tumor susceptibility in DAPK1-deficient mice.

Main Results:

• Inhibition of DAPK1 activity enhanced CD62L and CCR7 expression, similar to rapamycin.
• Deletion of DAPK1 domains impaired T cell activation and maintained homing receptor expression.
• DAPK1 deficiency increased tumor susceptibility and significantly reduced CD8+ T cell tumor infiltration.

Conclusions:

• DAPK1 plays a critical role in mediating CD8+ T cell trafficking into tumors.
• DAPK1-mTORC1 signaling is a key regulator of CD8+ T cell migration and antitumor efficacy.