galectin 9

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Ligands
galectin 9 (Human)

GtoPdb Ligand ID: 9594

Synonyms: Ecalectin | Gal-9 | Tumor antigen HOM-HD-21

Compound class: Endogenous peptide in human, mouse or rat

Comment: Galectin 9 is a secreted lectin that is an endogenous ligand of the immune co-inhibitory receptor, TIM3. Galectins bind β-galactoside sugar modifications on proteins, and have been associated with metastasis and immunosuppression. Galectin 9 contains two tandem carbohydrate recognition domains (CRD) within its peptide structure. The CRDs are homologous but distinct in their primary sequence. The whole peptide sequence provided here is for the longest isoform reported to date. Uniprot records 6 human protein isoforms [2-3]. Isoform 2 is known as ecalectin, and is reported to be a novel eosinophil chemoattractant produced by T lymphocytes [1,4-5,7]. The regulation and function of galectin 9 in physiological and pathological conditions was reviewed by Hirashima et al. (2004) [6].

Species: Human

Immunopharmacology Comments
Galectin 9 triggering of Tim3 has been shown to induce cell death in Tim3⁺ Th1 cells and ameliorate experimental autoimmune encephalomyelitis (EAE) [8], and to negatively regulate Th1-mediated immunity [9]. Differential regulation of mouse Lgals9 isoform expression has been detected during normal and pathological pregnancies. In human placental tissues a decrease in LGALS9 D5/10 isoform expression associates with spontaneous abortion [2].

Immunopharmacology Comments

Galectin 9 triggering of Tim3 has been shown to induce cell death in Tim3⁺ Th1 cells and ameliorate experimental autoimmune encephalomyelitis (EAE) [8], and to negatively regulate Th1-mediated immunity [9]. Differential regulation of mouse Lgals9 isoform expression has been detected during normal and pathological pregnancies. In human placental tissues a decrease in LGALS9 D5/10 isoform expression associates with spontaneous abortion [2].