DCAF1 controls T-cell function via p53-dependent and -independent mechanisms

Area of Science:

• Immunology
• Cell Biology
• Molecular Biology

Background:

• Naive T-cell activation involves growth and cell cycle entry for immune responses.
• Regulation of T-cell growth and cell cycle entry is not fully understood.

Purpose of the Study:

• To investigate the role of DCAF1 (Ddb1-cullin4-associated-factor 1) in T-cell activation, growth, and cell cycle regulation.
• To elucidate the mechanisms by which DCAF1 influences T-cell function in vivo.

Main Methods:

• T-cell-specific DCAF1 deletion models.
• Analysis of T-cell homeostasis, activation, cell cycle progression, and proliferation.
• In vivo studies of anti-viral and autoimmune responses.
• Investigation of p53 stabilization and MDM2-mediated ubiquitination.

Main Results:

• DCAF1 deletion impairs peripheral T-cell homeostasis.
• DCAF1 is upregulated upon T-cell receptor activation and is critical for T-cell growth, cell cycle entry, and proliferation.
• DCAF1 is essential for T-cell expansion and function during in vivo immune responses.
• DCAF1 deficiency causes p53 stabilization due to impaired MDM2-mediated p53 poly-ubiquitination.
• p53 deletion rescues DCAF1-deficient T-cell cycle entry but not growth defects.

Conclusions:

• DCAF1 is vital for T-cell activation, growth, and cell cycle entry.
• DCAF1 regulates T-cell function through both p53-dependent and p53-independent pathways.
• DCAF1 plays a critical role in adaptive immunity in vivo.