Molecular recognition in C-type lectins: the cases of DC-SIGN, Langerin, MGL, and L-sectin

Carbohydrates play a pivotal role in intercellular communication processes. In particular, glycan antigens are key for sustaining homeostasis, helping leukocytes to distinguish damaged tissues and invading pathogens from healthy tissues. From a structural perspective, this cross-talk is fairly complex, and multiple membrane proteins guide these recognition processes, including lectins and Toll-like receptors. Since the beginning of this century, lectins have become potential targets for therapeutics for controlling and/or avoiding progression of pathologies derived from an incorrect immune outcome, including infectious processes, cancer or autoimmune diseases. Therefore, a detailed knowledge about these receptors is mandatory for the development of specific treatments. In this review, we summarize the current knowledge about four key C-type lectins whose importance has been steadily growning in the last years, specially focusing on how glycan recognition takes place at the molecular level, also focusing on the recent progresses in the quest for therapeutics.