Syndecan-1 regulates dendritic cell migration in cutaneous hypersensitivity to haptens

Area of Science:

• Immunology
• Cell Biology

Background:

• Syndecan-1 (SDC1) is downregulated during dendritic cell (DC) maturation in vitro, correlating with increased motility.
• The in vivo role of SDC1 in DC migration and immune responses remains unclear.

Purpose of the Study:

• To investigate the role of SDC1 in DC migration during TNCB-induced cutaneous hypersensitivity reaction (CHS) in mice.

Main Methods:

• Utilized SDC1-deficient (SDC1-/-) and wild-type (WT) mice in a TNCB-induced CHS model.
• Performed adoptive transfer experiments with hapten- and fluorochrome-labeled DCs.
• Analyzed DC migration to lymph nodes, CCR7 expression, chemokine upregulation (CCL2, CCL3), and VCAM1/talin expression during maturation.
• Assessed T-cell-stimulating capacity and DC migration towards CCL21 and CCL19.

Main Results:

• SDC1-deficient mice exhibited faster and increased DC migration to lymph nodes draining the painted skin.
• Adoptive transfer of SDC1-deficient DCs into WT mice resulted in enhanced DC migration and stronger CHS.
• SDC1-deficient DCs showed prolonged CCR7 expression, increased CCL2, CCL3, VCAM1, and talin upregulation, and enhanced migration towards CCL21/CCL19.
• No difference in T-cell-stimulating capacity was observed between SDC1-deficient and WT DCs.

Conclusions:

• SDC1 negatively regulates DC migration in vivo.
• Enhanced DC migration due to SDC1 deficiency leads to exacerbated CHS.
• SDC1 influences DC migration potentially through modulation of CCR7 function and chemokine signaling pathways.