LAG3 (lymphocyte-activation protein 3) or CD223 is a single pass type I transmembrane glycoprotein that belongs to the Immunoglobulin superfamily (IgSF).  LAG3 contains 4 Ig-like motifs (1 IgV-type and 3 IgC2-type) in the extracellular domain (ECD) in addition to a transmembrane (TM) domain and a cytoplasmic tail.  The LAG3 sequence, exon/intron organization, and chromosomal localization indicate a close relationship to CD4. LAG3 is expressed on the cell surface of activated NK and T-lymphocytes.  LAG3 is involved in lymphocyte activation and can directly bind to HLA or MHC class-II (HLA-II or MHC-II) antigens. LAG-3 has ~20% amino acid sequence homology to CD4, but it binds to MHC-II with higher affinity than CD4.  Like PD1, LAG3 provides negative regulation of T cell receptor (TCR) signaling. The LAG-3/MHC-II pathway may synergize with PD-1 to regulate T cell-mediated immune responses. LAG3 is expressed on activated CD4+CD25+ Treg cells that may be responsible for directing an immune-suppressive environment.   A soluble form of LAG3 (sLAG3), can be shed by metalloproteinases, allowing for normal T cell activation by removing negative regulation.  Binding of dimeric sLAG-3-Fc fusion protein to MHC-II induces maturation of immature DC, and secretion of cytokines by cytotoxic T cells and NK cells, making it a potential adjuvant to stimulate anti-cancer immunity. LAG3 represents a promising target for immunotherapy.

LAG3 (lymphocyte-activation protein 3) or CD223 is a single pass type I transmembrane glycoprotein that belongs to the Immunoglobulin superfamily (IgSF).  LAG3 contains 4 Ig-like motifs (1 IgV-type and 3 IgC2-type) in the extracellular domain (ECD) in addition to a transmembrane (TM) domain and a cytoplasmic tail.  The LAG3 sequence, exon/intron organization, and chromosomal localization indicate a close relationship to CD4. LAG3 is expressed on the cell surface of activated NK and T-lymphocytes.  LAG3 is involved in lymphocyte activation and can directly bind to HLA or MHC class-II (HLA-II or MHC-II) antigens. LAG-3 has ~20% amino acid sequence homology to CD4, but it binds to MHC-II with higher affinity than CD4.  Like PD1, LAG3 provides negative regulation of T cell receptor (TCR) signaling. The LAG-3/MHC-II pathway may synergize with PD-1 to regulate T cell-mediated immune responses. LAG3 is expressed on activated CD4+CD25+ Treg cells that may be responsible for directing an immune-suppressive environment.   A soluble form of LAG3 (sLAG3), can be shed by metalloproteinases, allowing for normal T cell activation by removing negative regulation.  Binding of dimeric sLAG-3-Fc fusion protein to MHC-II induces maturation of immature DC, and secretion of cytokines by cytotoxic T cells and NK cells, making it a potential adjuvant to stimulate anti-cancer immunity. LAG3 represents a promising target for immunotherapy.

 

Product Details

 

Gene Symbol: LAG3; CD223; LAG-3

 

NCBI Gene ID: 3902

 

Uniprot Entry: P18627

 

Construct Details: Expressed as the combination of a heavy chain (HC) containing VH from anti-LAG3 mAb and CH1-3 region of human IgG1 and a light chain (LC) encoding VL from anti-LAG3 mAb and CL of human kappa light chain.  Exists as a disulfide linked dimer of the HC and LC hetero-dimer under non-reducing condition.

 

Source:  Mammalian cells stably expressing anti-LAG3 human heavy chain and light chain and growing in chemical-defined media with no animal components or antibiotics 

 

M.W.: Calculated molecular mass (kDa): 146 (49 kDa for a single HC, 24 kDa for a single LC); Estimated by SDS-PAGE under non-reducing condition(kDa): 150

 

Purity: >95% judged by SDS-PAGE under reducing condition (see the gel image above, labeled as DTT "+")

 

Formulation: Supplied at 0.25 mg/ml in sterile PBSpH7.4 (carrier free).  The purified recombinant antibody was labeled with Biotin (3-5 Biotin per IgG molecule) using the standard procedure.

 

Endotoxin Level: <0.1 EU per 1 μg of purified recombinant protein determined by the LAL method

 

Biological Activity: Binds to human LAG3 protein with high affinity.  Recognizes cell surface LAG3 by flow cytometry, IHC staining and fluorescent microscopy.  Blocks LAG3’s binding to MHC-II and enhances anti-tumor immunity in vivo.

 

  

FOR RESEARCH USE ONLY. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE IN HUMAN.

Restriction: This product is not transferable or re-sellable.  Customer obtain no right to transfer, assign, or sublicense its use rights, or to transfer, resell, package, or otherwise distribute the product, or to use the product for the benefit of any third party or for any commercial purpose.  Customer may only use the product in compliance with applicable local, state and federal laws, regulations and rules.  Customer may not directly or indirectly use the product or allow the transfer, transmission, export or re-export of all or any part of the product in violation of any export control law or regulation of the united states or any other relevant jurisdiction.  Your use of this product constitutes acceptance of the terms of this limited use agreement.  Please refer to our “terms & conditions” for details.  If you are not willing to accept the limitation of this agreement, G&P Biosciences will accept return of the product for a full/partial refund.

 

Storage

 

The product is shipped at 4°C. Upon receipt, centrifuge the product briefly before opening the vial. It is recommended to store small aliquots at the temperature below –20°C for long-term storage and the product is stable for 3 months. The undiluted protein can be stored at 4°C for no more than 2 weeks.

 

 

Use a manual defrost freezer and avoid repeated freeze-thaw cycles.

 

 

 

 

FOR RESEARCH USE ONLY. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE IN HUMAN.

 

References

 

1. J. Exp. Med. 171:1393 (1990)

2. J. Exp. Med. 176:327 (1992)

3. J. Immunol. 172:5450 (2004)

4. Immunity 21:503 (2004)

5. J Immunol. 194:3873 (2015)

 

 

 

Documentation

 

Product datasheet (pdf) can be downloaded here: MAB1896B-PDS.pdf

 

 

 

Additional supporting documents, including COA and MSDS are available upon request.

 

 

 

FOR RESEARCH USE ONLY. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE IN HUMAN.

Restriction: This product is not transferable or re-sellable.  Customer obtain no right to transfer, assign, or sublicense its use rights, or to transfer, resell, package, or otherwise distribute the product, or to use the product for the benefit of any third party or for any commercial purpose.  Customer may only use the product in compliance with applicable local, state and federal laws, regulations and rules.  Customer may not directly or indirectly use the product or allow the transfer, transmission, export or re-export of all or any part of the product in violation of any export control law or regulation of the united states or any other relevant jurisdiction.  Your use of this product constitutes acceptance of the terms of this limited use agreement.  Please refer to our “terms & conditions” for details.  If you are not willing to accept the limitation of this agreement, G&P Biosciences will accept return of the product for a full/partial refund.