Recognition of tumor glycans by antigen-presenting cells.

C-type lectin receptors on antigen-presenting cells are potent antigen-uptake receptors with specificity for glycan structures. Glycosylation changes during malignant transformation create tumor-specific carbohydrate structures that interact with C-type lectins on dendritic cells. Recent findings revealed that tumor glycoproteins, such as carcinoembryonic antigen and MUC-1, indeed interact with the C-type lectins DC-SIGN and macrophage galactose-type lectin on antigen-presenting cells. The consequences for anti-cancer immunity or tolerance induction can be extrapolated from the function of C-type lectins in pathogen recognition and antigen presentation. In addition, in vivo studies in mice recently demonstrated the potency of targeting antigens to C-type lectins on antigen-presenting cells for anti-tumor vaccination strategies.