LECTIN-CARBOHYDRATE INTERACTION IN THE IMMUNE-SYSTEM

The immune system consists of various types of cells and molecules tha t specifically interact with each other to initiate the host defense m echanism. Recent studies have shown that carbohydrates and lectins (ca rbohydrate-binding proteins) play an essential role in mediating such interactions. Both lectins and carbohydrates are widely distributed in the mammalian tissues as well as in microorganisms. Carbohydrates, du e to their chemical nature, can potentially form structures that are m ore variable than proteins and nucleic acids. Lectins can exist in eit her soluble or cell-associated form, and although overall structures v ary, invariably possess carbohydrate-recognition domains (CRD) with va rious specificities. The interaction between lectins and carbohydrates have been shown to be involved in such activities as opsonization of microorganisms, phagocytosis, cell adhesion and migration, cell activa tion and differentiation, and apoptosis. The number of lectins identif ied in the immune system is increasing at a rapid pace. The developmen t in this area has opened a new aspect in studying the immune system, and at the same time, provided new therapeutic routes for the treatmen t and prevention of disease.