Structure-function dissection of D6, an atypical scavenger receptor

Area of Science:

• Immunology
• Cell Biology
• Biochemistry

Background:

• Chemokines regulate leukocyte migration via G-protein coupled receptors.
• Atypical chemokine receptors, like D6, bind chemokines but lack canonical signaling pathways.
• D6 exhibits high affinity for pro-inflammatory chemokines but does not signal upon binding.

Purpose of the Study:

• To investigate the function of atypical chemokine receptor D6.
• To elucidate the mechanism by which D6 influences chemokine bioavailability and inflammation.
• To develop methods for expressing, purifying, and analyzing D6 protein for structural studies.

Main Methods:

• Functional assays in heterologous cell lines to assess D6 signaling and chemokine binding.
• In vivo studies using D6-deficient mice to evaluate inflammatory responses.
• Protein expression, purification, and stability analysis of D6.

Main Results:

• D6 functions as a chemokine scavenger, sequestering extracellular chemokines via unique intracellular trafficking.
• D6-deficient mice display exaggerated inflammatory responses, confirming D6's anti-inflammatory role.
• High-level expression and purification of stable D6 protein were achieved, suitable for structural analysis.

Conclusions:

• Chemokine scavenging by D6 represents a novel paradigm in chemokine biology.
• D6 limits pro-inflammatory chemokine bioavailability, thereby suppressing inflammation in vivo.
• The developed methods facilitate structural studies of D6, potentially revealing insights into atypical chemokine receptor function.