title: Characterization of galectin-9-induced death of Jurkat T cells.
abstract: Galectin-9, a mammalian lectin with affinity for beta-galactosides, is known as an apoptosis inducer of activated T lymphocytes. In the present study, we examined the properties of galectin-9-mediated cell death of Jurkat T cells. Galectin-9NC (wild-type), consisting of two CRDs (N-terminal and C-terminal carbohydrate recognition domains), and derivatives of it, galectins-9-NN and -9-CC, induced Jurkat T-cell apoptosis. However, a single CRD (galectin-9NT or -CT) had no effect, suggesting the stable dimeric structure of two CRDs is required for the activity. The apoptosis was inhibited by pretreatment with an N-glycan synthesis inhibitor, indicating that the expression of N-glycans in the cells is essential for galectin-9-induced apoptosis. We previously showed that the apoptosis of MOLT-4 cell is mediated by galectin-9 via a Ca(2+)-calpain-caspase-1-dependent pathway. In Jurkat cells, the cell death by galectin-9, was insufficiently suppressed by caspase inhibitors, Ca(2+)-chelator or calpain inhibitor. Furthermore, we observed the loss of mitochondrial membrane potential and significant AIF release in galectin-9-treated cells. These findings suggest that caspase-dependent and-independent death pathways exist in Jurkat cells, and the main pathway might vary with the T-cell type.
authors.affiliation: Department of Endocrinology, Faculty of Medicine, Kagawa University, Kagawa, Japan.
authors.forename: Liang-Hao
authors.initials: LH
authors.lastname: Lu
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Nakagawa
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Kashio
authors.forename: Aiko
authors.initials: A
authors.lastname: Ito
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shoji
authors.forename: Nozomu
authors.initials: N
authors.lastname: Nishi
authors.forename: Mitsuomi
authors.initials: M
authors.lastname: Hirashima
authors.forename: Akira
authors.initials: A
authors.lastname: Yamauchi
authors.forename: Takanori
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D020170:Caspase 1 / Q000378:metabolism; D045744:Cell Line, Tumor; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D037161:Galectins / Q000378:metabolism*; D006801:Humans; D019169:Jurkat Cells; D011994:Recombinant Proteins / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology*
chemical_list: D015853:Cysteine Proteinase Inhibitors; D037161:Galectins; C105032:LGALS9 protein, human; D011994:Recombinant Proteins; D020170:Caspase 1; D002118:Calcium