Human Lymphocyte Activation Gene3 Protein,LAG3 ELI

Lymphocyte activation gene 3 protein: Inhibitory receptor on antigen activated T-cells (PubMed:7805750, PubMed:8647185, PubMed:20421648).

Delivers inhibitory signals upon binding to ligands, such as FGL1 (By similarity).

FGL1 constitutes a major ligand of LAG3 and is responsible for LAG3 T-cell inhibitory function (By similarity).

Following TCR engagement, LAG3 associates with CD3-TCR in the immunological synapse and directly inhibits T-cell activation (By similarity).

May inhibit antigen-specific T-cell activation in synergy with PDCD1/PD-1, possibly by acting as a coreceptor for PDCD1/PD-1 (By similarity).

Negatively regulates the proliferation, activation, effector function and homeostasis of both CD8(+) and CD4(+) T-cells (PubMed:7805750, PubMed:8647185, PubMed:20421648).

Also mediates immune tolerance: constitutively expressed on a subset of regulatory T-cells (Tregs) and contributes to their suppressive function (By similarity).

Also acts as a negative regulator of plasmacytoid dendritic cell (pDCs) activation (By similarity).

Binds MHC class II (MHC-II); the precise role of MHC-II-binding is however unclear (PubMed:8647185).

{ECO:0000250|UniProtKB:Q61790, ECO:0000269|PubMed:20421648, ECO:0000269|PubMed:7805750, ECO:0000269|PubMed:8647185}.; [Secreted lymphocyte activation gene 3 protein]: May function as a ligand for MHC class II (MHC-II) on antigen-presenting cells (APC), promoting APC activation/maturation and driving Th1 immune response.

{ECO:0000250|UniProtKB:Q61790}.