Wnt5A signaling supports antigen processing and CD8 T cell activation

Area of Science:

• Immunology
• Cell Biology
• Molecular Signaling

Background:

• Cell-mediated immunity relies on antigen processing and CD8 T cell activation.
• The precise coordination between these processes remains incompletely understood.

Purpose of the Study:

• To investigate the role of Wnt5A signaling in dendritic cells for antigen processing and CD8 T cell activation.
• To elucidate the molecular mechanisms involving actin and proteasome dynamics.

Main Methods:

• Utilized mouse bone marrow-derived dendritic cells (BMDCs) and Ovalbumin (OVA)/DQ-Ovalbumin (DQ-OVA) as a model antigen.
• Manipulated Wnt5A signaling via recombinant Wnt5A and gene depletion.
• Assessed antigen processing, proteasome activity, actin dynamics, and CD8 T cell activation.
• Employed proteasome inhibitor MG132 and analyzed Wnt5A heterozygous mice.

Main Results:

• Wnt5A signaling in BMDCs enhanced DQ-OVA processing and CD8 T cell activation.
• Wnt5A depletion impaired OVA processing, presentation, and CD8 T cell activation.
• Altered actin and proteasome dynamics (PA28α-PA28β) were observed in Wnt5A-depleted BMDCs.
• Reduced OVA processing and CD8 T cell response were found in Wnt5A heterozygous mice.

Conclusions:

• Wnt5A signaling is essential for efficient antigen processing and presentation by dendritic cells.
• Wnt5A regulates actin and proteasome dynamics, impacting CD8 T cell activation.
• This study identifies Wnt5A as a key regulatory node in cell-mediated immunity.