Galectin-1, an alternative signal for T cell death, is increased in activated macrophages

Galectin-1 belongs to an evolutionarily conserved family of animal beta-gal actoside-binding proteins, which exert their functions by crosslinking the oligosaccharides of specific glycoconjugate ligands. During the past decade , attempts to identify the functional role of galectin-1 suggested particip ation in the regulation of the immune response. Only in the last few years has the molecular mechanism involved in Only in the last few years has the molecular mechanism involved in these properties been clearly elucidated, r evealing a critical role for galectin-1 as an alternative signal in the gen eration of T cell death. Ln the present study we will discuss the latest ad vances in galectin research in the context of the regulation of the immune response, not only at the central level but also at the periphery. Moreover , we will review the purification, biochemical properties and functional si gnificance of a novel galectin-1-like protein from activated rat macrophage s, whose expression is differentially regulated according to the activation state of the cells. The novel role of a carbohydrate-binding protein in th e regulation of apoptosis is providing a breakthrough in galectin research and extending the interface between immunology, glycobiology and clinical m edicine.