Apoptosis of T cells mediated by galectin-1.
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.
Perillo
N L
NL
UCLA Department of Pathology and Laboratory Medicine, Los Angeles, California 90095-1732, USA.
Pace
K E
KE
Seilhamer
J J
JJ
Baum
L G
LG
D015703:Antigens, CD; D017209:Apoptosis / Q000502:physiology*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology; D037483:Galectin 1; D006388:Hemagglutinins / Q000502:physiology*; D006801:Humans; D037102:Lectins / Q000502:physiology*; D017493:Leukocyte Common Antigens / Q000502:physiology; D051917:Leukosialin; D012795:Sialoglycoproteins / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology*; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; D037483:Galectin 1; D006388:Hemagglutinins; D037102:Lectins; D051917:Leukosialin; C465014:SPN protein, human; D012795:Sialoglycoproteins; D017493:Leukocyte Common Antigens