mLAG-3

mLAG-3 (murine Lymphocyte-activation gene 3) functions as an inhibitory immune checkpoint that modulates T cell activation and maintains immune homeostasis^[1][2]. Mechanistically, mLAG-3 binds to MHC class II molecules, delivering inhibitory signals that suppress CD4⁺ and CD8⁺ T cell proliferation and cytokine production^[2][3]. Compared with related isoforms, such as human LAG-3 and other checkpoint receptors like PD-1, mLAG-3 exhibits distinct tissue distribution and a higher affinity for certain MHC class II conformations, influencing its immunoregulatory potency^[3][4]. In disease models, mLAG-3 regulates antitumor immunity by restraining effector T cell responses and is implicated in controlling viral persistence and autoimmunity^[1][5]. Agonists targeting mLAG-3 can enhance regulatory T cell activity and reduce autoimmune pathology, whereas antagonists or blocking antibodies have been shown to restore exhausted T cell function in cancer or chronic infection models^[2][6]. Experimental applications leverage mLAG-3 modulation to dissect immune tolerance mechanisms, evaluate combinatorial checkpoint therapies, and explore synergistic effects with cytokine agonists such as IL-2 or IL-7^[1][6]. Collectively, mLAG-3 represents a functionally unique checkpoint receptor with both mechanistic and translational significance for immunological research.