Anti-LAG3 Rabbit Polyclonal Antibody for WB and ELISA - P18627

Core Product Specifications and Parameters

Biological Background: LAG3 Function and Localization

• Lymphocyte activation gene 3 protein (LAG3, CD223) is an inhibitory receptor on antigen-activated T-cells, delivering negative regulatory signals upon ligand binding. Related references: PMID:20421648, PMID:35761082, PMID:7805750
• Its primary ligand is MHC class II on antigen-presenting cells; it also binds FGL1 secreted by hepatocytes and certain tumor cells. Related references: PMID:30580966, PMID:32920841, PMID:35761082
• LAG3 inhibits T-cell receptor (TCR) signaling by disrupting the CD3E-LCK association, a process that involves ubiquitination of the KIEELE motif and formation of condensates with CD3E. Related references: PMID:40101708, PMID:40592325
• It synergizes with PD-1 to inhibit antigen-specific T-cell activation and negatively regulates the proliferation, activation, and homeostasis of both CD8+ and CD4+ T-cells. Related references: PMID:20421648, PMID:7805750, PMID:8647185
• On regulatory T-cells, LAG3 contributes to their suppressive function, and it also acts as a negative regulator of plasmacytoid dendritic cell activation (By similarity).
• The LAG3 inhibitory pathway is exploited by tumors to evade anti-tumor immunity; blockade of LAG3 and PD-1 can reverse T-cell exhaustion, providing a rationale for cancer immunotherapy. Related references: PMID:35981087, PMID:40101708
• LAG3 may also function as a ligand for MHC-II on antigen-presenting cells, promoting APC activation/maturation and driving a Th1 immune response.
• Subcellularly, LAG3 is found at the cell membrane and can be secreted; it is primarily expressed in activated T-cells and a subset of NK cells. Key molecular features include immunoglobulin domains, disulfide bonds, glycosylation, and ubiquitination.

Experimental Guidance and Technical Tips

• The immunogen corresponds to the N-terminal extracellular region (aa 29–170), which contains Ig-like domains likely involved in ligand binding; the antibody may recognize native and recombinant LAG3.
• For Western blot, a band near 57 kDa is expected; consider using reducing conditions and validating with activated T-cell lysates or LAG3-transfected cell lines.
• This polyclonal antibody is suitable for ELISA; titration and pairing with a capture antibody may be necessary for sandwich ELISA development.
• Cross-reactivity with mouse and rat LAG3 has been observed; however, sequence alignment and preliminary testing in the relevant species model are recommended.
• As with any polyclonal reagent, lot-to-lot variability is possible; include positive and negative controls and consider an initial pilot experiment to confirm reactivity in your assay system.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio supports diagnostic manufacturers and research institutions with a comprehensive range of IVD raw materials, including validated antibody pairs, monoclonal and polyclonal antibodies, and bulk ancillary reagents. For immune checkpoint targets like LAG3, our portfolio and sourcing capabilities can help accelerate the development of immunoassays or immunohistochemistry tests. Whether you need off-the-shelf products or custom rare-target sourcing, CamelBio serves as a reliable partner from concept to clinic.