MGL‐mediated internalization and antigen presentation by dendritic cells: A role for tyrosine‐5

• Published in: European Journal of Immunology 2007-08, Vol.37 (8), p.2075-2081
• Main Authors: van Vliet, Sandra J., Aarnoudse, Corlien A., Broks‐van den Berg, Venice C. M., Boks, Martine, Geijtenbeek, Teunis B. H., van Kooyk, Yvette
• Format: Article
• Language: English
• Subjects: Amino Acid Motifs - immunology; Amino Acid Sequence; Animals; Antigen Presentation - immunology; CHO Cells; Cricetinae; Cricetulus; C‐type lectin; Dendritic cells; Dendritic Cells - immunology; Endocytosis; Endocytosis - immunology; Flow Cytometry; Humans; Lectins, C-Type - chemistry; Lectins, C-Type - genetics; Lectins, C-Type - immunology; MHC class II; Microscopy, Confocal; Molecular Sequence Data; Tyrosine
• ISSN: 0014-2980; 1521-4141; 1365-2567
• DOI: 10.1002/eji.200636838

Professional antigen‐presenting cells are essential for the initiation of adaptive immune responses; however, they also play a vital role in the maintenance of tolerance towards self‐antigens. C‐type lectins can function as antigen receptors by capturing carbohydrate ligands for processing and presentation. Here, we focused on the dendritic cell (DC)‐expressed macrophage galactose‐type lectin (MGL), a C‐type lectin with a unique specificity for terminal GalNAc residues, such as the tumor‐associated Tn antigen. Soluble model antigens are efficiently internalized by MGL and subsequently presented to responder CD4+ T cells. The tyrosine‐5 residue in the YENF motif, present in the MGL cytoplasmic domain, was essential for the MGL‐mediated endocytosis in CHO cells. In conclusion, MGL contributes to the antigen processing and presentation capacities of DC and may provide a suitable target for the initiation of anti‐tumor immune responses.