Basophil and eosinophil activation by CC chemokines

Area of Science:

• Immunology
• Cell Biology
• Biochemistry

Background:

• CC chemokines are crucial for immune cell trafficking and activation.
• Selective attraction of monocytes, lymphocytes, eosinophils, and basophils by CC chemokines is observed, but not neutrophils.
• Distinct target cell selectivities suggest roles in chronic inflammation and allergic diseases.

Purpose of the Study:

• To investigate the distinct bioactivities and target cell profiles of human CC chemokines.
• To identify and characterize CC chemokine receptors on basophils and eosinophils.
• To explore structure-function relationships of CC chemokines for developing targeted therapies.

Main Methods:

• Functional and desensitization studies on basophils and eosinophils.
• Analysis of bioactivities and target cell profiles for all six human CC chemokines.
• Utilizing chemokine mutants and hybrids to study structure-function relationships.

Main Results:

• At least three distinct G-protein-coupled CC chemokine receptors identified on basophils, and two on eosinophils.
• These receptors exhibit partially selective and overlapping ligand specificities, mediating distinct functions.
• CC chemokine sequence homology does not predict cell function or preferential activation; discrete sequence motifs are likely key.

Conclusions:

• CC chemokines possess distinct bioactivities and target cell profiles, mediated by specific CC chemokine receptors.
• Structure-function analyses reveal the importance of discrete sequence motifs in chemokine-receptor interactions.
• These findings pave the way for developing disease-selective anti-inflammatory antagonists.