Apoptosis of T cells mediated by galectin-1

Perillo, Nancy L.
Pace, Karen E.
Seilhamer, Jeffrey J.
Baum, Linda G.

UCLA Department of Pathology and Laboratory Medicine, 10833 Le Conte Avenue, Los Angeles, California 90095-1732, USA.
(Seilhamer) Incyte Pharmaceuticals Inc., 3174 Porter Drive, Palo Alto, California 94304, USA.
(Baum) To whom correspondence should be addressed.

Nature 378(6558):p 736-739, December 14, 1995.

GALECTIN-1, a member of the family of beta-galactoside binding proteins , has growth regulatory and immunomodulatory activities . We report here that galectin-1, expressed by stromal cells in human thymus and lymph nodes , is present at sites of cell death by apoptosis during normal T-cell development and maturation. Galectin-1 induced apoptosis of activated human T cells and human T leukaemia cell lines. Resting T cells also bound galectin-1, but did not undergo apoptosis. Human endothelial cells that expressed galectin-1 induced apoptosis of bound T cells. Galectin-1-induced apoptosis required expression of CD45, and was decreased when N-glycan elongation was blocked by treatment of the cells by swainsonine , whereas inhibition of O-glycan elongation potentiated the apoptotic effect of galectin-1. Induction of apoptosis by an endogenous mammalian lectin represents a new mechanism for regulating the immune response.