Carbohydrates and antigen recognition by T cells

Area of Science:

• Immunology
• Glycobiology
• Molecular Biology

Background:

• T lymphocytes (T cells) recognize peptide antigens bound to MHC molecules.
• Antibodies bind native antigens, while T cells require processed peptides.
• The detailed mechanisms of antigen processing and T cell recognition are increasingly understood.

Purpose of the Study:

• To highlight the emerging role of carbohydrate moieties in T cell recognition.
• To explore how glycans on antigens modulate T cell responses.
• To discuss the implications for understanding T cell epitopes and immune responses.

Main Methods:

• Analysis of T cell recognition of model T cell epitopes.
• Identification of glycopeptide-specific T cell responses.
• Investigation of T cell responses to native glycoproteins.

Main Results:

• Carbohydrates on glycoprotein antigens can contribute to T cell epitope recognition by MHC molecules.
• Glycopeptide-specific T cell responses were identified, often involving single glycosyl residues.
• Both glycan and peptide components likely interact with the T cell receptor binding site.
• Glycopeptide-specific T cell responses were also observed against native glycoproteins.

Conclusions:

• Carbohydrate structures play a significant role in modulating T cell recognition of antigens.
• This finding has broad implications for understanding immune responses and T cell determinant mapping.
• The interaction between glycans, peptides, MHC molecules, and T cell receptors is complex and crucial for immunity.