The carbohydrate recognition by cytokines modulates their physiological activities

Area of Science:

• Immunology
• Glycobiology
• Molecular Biology

Background:

• Cytokines are crucial signaling molecules in the immune system.
• Specific carbohydrate moieties on cellular receptors can be recognized by certain cytokines.
• Previous studies identified carbohydrate recognition for fibroblast growth factor (FGF), tumor necrosis factor (TNF)-alpha, and interleukin (IL)-2.

Purpose of the Study:

• To investigate the role of specific carbohydrate recognition in cytokine function.
• To expand the understanding of cytokines that modulate functions via carbohydrate recognition.
• To systematically elucidate the biological functions of cytokine-carbohydrate interactions in the immune system.

Main Methods:

• Analysis of cytokine-carbohydrate interactions using blocking strategies.
• Assessing the impact of blocking these interactions on cytokine-induced signaling and cellular responses.
• Investigating the recognition of heparan sulfate proteoglycans by FGF family receptors.
• Examining the recognition of high-mannose type glycan on the IL-2 receptor alpha subunit by IL-2.
• Studying the recognition of mannose 6-phosphate diester in glycosylphosphatidylinositol (GPI)-anchored glycoproteins by TNF-alpha.

Main Results:

• FGF family receptors recognize heparan sulfate proteoglycans, forming complexes that induce signal transduction.
• Interleukin-2 (IL-2) recognizes a high-mannose type glycan and a peptide portion on its receptor's alpha subunit.
• Blocking the carbohydrate-IL-2 interaction reduced IL-2-induced signaling and T-cell proliferation.
• Tumor necrosis factor-alpha (TNF-alpha) recognizes a specific mannose 6-phosphate diester on GPI-anchored glycoproteins.
• Blocking the GPI-anchored glycan-TNF-alpha interaction abrogated TNF-alpha-induced apoptosis.

Conclusions:

• Cytokine function is modulated by specific carbohydrate recognition.
• Interleukin-2 and Tumor Necrosis Factor-alpha exhibit distinct carbohydrate-binding specificities.
• Understanding these interactions provides insights into immune system regulation and potential therapeutic targets.