LGALS9 (Galectin-9) is a member of the galectin family, a group of β-galactoside-binding lectins involved in immune regulation, inflammation, and cancer progression. Structurally, LGALS9 contains two carbohydrate recognition domains (CRDs) connected by a linker peptide, enabling interactions with various glycoproteins. It is broadly expressed in immune cells (e.g., T cells, dendritic cells), endothelial cells, and epithelial tissues. Functionally, LGALS9 acts as a ligand for TIM-3 (T-cell immunoglobulin and mucin domain-containing protein 3), a co-inhibitory receptor on T cells and innate immune cells, playing a key role in modulating immune tolerance, T-cell exhaustion, and tumor immune evasion. Dysregulated LGALS9 expression is linked to autoimmune diseases, chronic infections, and cancer.
LGALS9 antibodies are tools or therapeutics designed to target LGALS9 or its signaling pathways. Monoclonal or polyclonal antibodies against LGALS9 are used experimentally to block its interaction with TIM-3. thereby reactivating T-cell responses in cancer models or mitigating immune suppression. In research, these antibodies help elucidate LGALS9's role in diseases like HIV, hepatitis, and multiple sclerosis. Therapeutically, anti-LGALS9 antibodies are under investigation to enhance anti-tumor immunity, particularly in combination with checkpoint inhibitors (e.g., anti-PD-1). Challenges include balancing efficacy with potential autoimmune side effects. Overall, LGALS9 antibodies represent a promising avenue for modulating immune responses in oncology and inflammatory disorders.