Lectins are proteins responsible for recognizing the signals of sugar molecules in the body. Sialic acid-binding immunoglobulin-like lectins (Siglecs) regulate the innate and adaptive immune responses in the tumor microenvironment by recognizing the glycan structure containing sialic acid and mediating downstream signals through immune receptor tyrosine inhibitory motifs. In recent years, a variety of tumor treatment strategies targeting the sialic acid-Siglecs axis have been introduced, including sialoglycoprotein-mediated drug delivery and antibody mediated inhibition of Siglecs from recognizing tumor surface ligands. In the future, by combining with glycoprotein nanotherapy, antibody therapy and gene therapy, Siglecs can be used to accurately locate tumor targets and release the anti-tumor immunity, so as to achieve the purpose of effective cure of tumors.
Sialic Acid Binding Immunoglobulin-like Lectins/metabolism* ; N-Acetylneuraminic Acid ; Immunoglobulins/metabolism* ; Receptors, Immunologic ; Ligands

OBJECTIVEIt is known that Siglec-8 is selectively expressed on human eosinophils at a high level and mediates eosinophil apoptosis when crosslinked with its antibody. The aim of our review is to elucidate the molecular and biological characteristic of Siglec-8 and then discuss the function and possible mechanisms of Siglec-8 in eosinophils. Thereby, we will expand our understanding to the regulation of eosinophil apoptosis, and provide important clues to the treatment of asthma and other hyper-eosinophilic diseases.

DATA SOURCESMost articles were identified by searching of PubMed online resources using the key term Siglecs.

STUDY SELECTIONMainly original milestone articles and critical reviews written by major pioneer investigators in the field were selected.

RESULTSSiglec-8 is selectively expressed on human eosinophil and can specifically induce eosinophil apoptosis.

CONCLUSIONThe restricted expression of Siglec-8 on human eosinophil and the rapid progress in understanding its role as cell signaling and activation of death receptors have made it an attractive target for treatment of asthma and other hyper-eosinophilic diseases.

Apoptosis ; genetics ; physiology ; Asthma ; metabolism ; therapy ; Eosinophils ; cytology ; metabolism ; Humans ; Sialic Acid Binding Immunoglobulin-like Lectins ; metabolism