LAG-3 Antibody (17B4)

Novus Biologicals, part of Bio-Techne | Catalog # NBP2-80059

Novus Biologicals, part of Bio-Techne

Key Product Details

Species Reactivity

Human

Applications

Flow Cytometry, Immunocytochemistry/ Immunofluorescence, Immunohistochemistry, Immunohistochemistry-Frozen, Immunoprecipitation, Inhibition Activity, Multiplex Immunofluorescence, Western Blot

Label

Unconjugated

Antibody Source

Monoclonal Mouse IgG1 kappa Clone # 17B4

Concentration

1 mg/ml

View all LAG-3 Antibodies »

Product Specifications

Immunogen

Synthetic peptide corresponding to 30 aa in the N-terminus of human LAG-3.

Specificity

Recognizes human LAG-3.

Clonality

Monoclonal

Host

Mouse

Isotype

IgG1 kappa

Endotoxin Level

<0.001EU/ug purified protein or <1EU/mg purified protein (LAL test)

Scientific Data Images for LAG-3 Antibody (17B4)

LAG-3 Antibody (17B4)

Detection of LAG-3 in Human Tonsil via Multiplex Immunofluorescence staining on COMET™

LAG-3 was detected in immersion fixed paraffin-embedded sections of human tonsil using Mouse Anti-Human LAG-3 Monoclonal Antibody (NOVUS Catalog # NBP2-80059) at 1:150 at 37 ° Celsius for 4 minutes. Before incubation with the primary antibody, tissue underwent an all-in-one dewaxing and antigen retrieval preprocessing using PreTreatment Module (PT Module) and Dewax and HIER Buffer H (pH 9). Tissue was stained using the Alexa Fluor™ 647 Goat anti-Mouse IgG Secondary Antibody at 1:200 at 37 ° Celsius for 2 minutes. (Yellow; Lunaphore Catalog # DR647MS) and counterstained with DAPI (blue; Lunaphore Catalog # DR100). Specific staining was localized to the membrane and cytoplasm. Protocol available in COMET™ Panel Builder.

Applications for LAG-3 Antibody (17B4)

Application
Recommended Usage

Immunohistochemistry

1:150

Immunohistochemistry-Frozen

1:150

Immunoprecipitation

10 ug/ml

Multiplex Immunofluorescence

1:150

Western Blot

5 ug

Formulation, Preparation, and Storage

Purification

Protein G purified

Formulation

PBS

Preservative

0.02% Sodium Azide

Concentration

1 mg/ml

Shipping

The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.

Stability & Storage

Store at 4C short term. Aliquot and store at -20C long term. Avoid freeze-thaw cycles.

Background: LAG-3

Lymphocyte activation gene-3 (LAG-3), also referred to as CD233, is a type I transmembrane protein with a theoretical molecular weight of 70 kDa that is a member of the immunoglobulin superfamily (IgSF) (1, 2). Human LAG-3 cDNA encodes 525 amino acids (aa) that includes a 28 aa signal sequence, a 422 aa extracellular domain (ECD) with four Ig-like domains (D1-D4), a transmembrane region and a highly charged cytoplasmic region. Within the ECD, human LAG-3 shares 70%, 67%, 76%, and 73% aa sequence identity with mouse, rat, porcine, and bovine LAG-3, respectively. The extracellular region of LAG-3 and the CD4 co-receptor share ~20% aa sequence homology but are structurally similar and both bind to major histocompatibility complex class II (MHCII) on antigen-presenting cells (APCs), although LAG-3 has much higher affinity (1, 3). LAG-3 is highly expressed in the lymph node, spleen, ovary, and appendix while expressed at a lower level in a variety of other tissues. More specifically, LAG-3 is expressed on activated CD4+ and CD8+ T cells, natural killer T (NKT) cells, natural killer (NK) cells, plasmacytoid dendritic cells (pDCs), and regulatory T cells (Tregs), but not on naive, or resting, T cells (1, 3).

As mentioned above, LAG-3 binds to MHCII and this occurs via a proline-rich amino acid loop in D1 (1, 3). Another unique feature of LAG-3 is the longer connecting peptide region between the D4 and the transmembrane, which is acted upon and cleaved by metalloproteinases a disintegrin and metallopeptidase domain (ADAM) 10 and ADAM17 to generate a soluble 54 kDa form of LAG-3 (sLAG-3) (1, 3). The interaction of LAG-3 with MHCII prevents the MHC molecule from binding to a T-cell receptor (TCR) or CD4, thereby functioning in an inhibitory role and suppressing the TCR signal (4). When LAG-3 crosslinks with the TCR/CD3 complex, it causes reduced T-cell proliferation and cytokine secretion (4). This negative regulation is important in controlling autoimmunity as one study found Lag3-/- NOD (non-obese diabetic) mice had accelerated diabetes onset and increased T-cell infiltration into islet cells (5). On the other hand, besides being a negative regulator of T-cells, LAG-3 binding to MHCII molecules on APCs induces dendritic cell maturation and cytokine secretion by monocytes (5, 6). In addition to MHCII, other reported ligands for LAG-3 includes fibrinogen-like protein 1 (FGL1), liver endothelial cell lectin (lSECtin), galectin-3 (Gal-3), and alpha-synuclein fibrils (1). Gal-3, for instance, is expressed on stromal cells and CD8+ T-cells in the tumor microenvironment and the interaction with LAG-3 was shown to be crucial for the suppression of secreted cytokine IFN-gamma and may control anti-tumor immune responses (1, 5). Interestingly, a mouse model of Parkinson's disease revealed LAG-3 binding to alpha-synuclein fibrils in the central nervous system, contributing to its pathogenesis (1, 5).

Recent cancer immunotherapeutic approaches have focused on inhibitory receptors such as LAG-3 to revive expression of cytotoxic T-cells to attack tumors (6). LAG-3 has been shown to be co-expressed and have synergy with another immune-checkpoint molecule called programmed-death 1 (PD-1) (1, 4, 5, 6). In a mouse model of colon adenocarcinoma LAG3 blockade alone was largely ineffective, however co-blockade of LAG-3 and PD-1 limited tumor growth and resulted in tumor clearance in 80% of mice, compared to 40% with PD-1 blockade alone (5). Additionally, in a model of fibrosarcoma the LAG-3/PD-1 duel blockade increased survival and the percentage of tumor-free mice (5). Analysis of a variety of human tumor samples (e.g. melanoma, colon cancer, head and neck squamous cell carcinoma) also suggest that LAG3 alone and combinatorial treatment with PD-1 may be a good target for treatment (1, 3-6). To date there are over 10 different agents targeting LAG-3 in clinical trials for cancer either as an anti-LAG-3 blocking antibody monotherapy or as a combination antagonist bispecific antibody, primarily with PD-1 (1, 3-6).

Alternative names for LAG-3 includes 17b4 lag3, 17b4 neutralizing, 17b4, CD223, FDC, LAG-3 17b4, LAG-3 blocking, and LAG3.

References

1. Maruhashi, T., Sugiura, D., Okazaki, I. M., & Okazaki, T. (2020). LAG-3: from molecular functions to clinical applications. Journal for Immunotherapy of Cancer, 8(2), e001014. https://doi.org/10.1136/jitc-2020-001014

2. Triebel, F., Jitsukawa, S., Baixeras, E., Roman-Roman, S., Genevee, C., Viegas-Pequignot, E., & Hercend, T. (1990). LAG-3, a novel lymphocyte activation gene closely related to CD4. The Journal of experimental medicine, 171(5), 1393-1405. https://doi.org/10.1084/jem.171.5.1393

3. Ruffo, E., Wu, R. C., Bruno, T. C., Workman, C. J., & Vignali, D. (2019). Lymphocyte-activation gene 3 (LAG3): The next immune checkpoint receptor. Seminars in immunology, 42, 101305. https://doi.org/10.1016/j.smim.2019.101305

4. Long, L., Zhang, X., Chen, F., Pan, Q., Phiphatwatchara, P., Zeng, Y., & Chen, H. (2018). The promising immune checkpoint LAG-3: from tumor microenvironment to cancer immunotherapy. Genes & cancer, 9(5-6), 176-189.

5. Andrews, L. P., Marciscano, A. E., Drake, C. G., & Vignali, D. A. (2017). LAG3 (CD223) as a cancer immunotherapy target. Immunological reviews, 276(1), 80-96. https://doi.org/10.1111/imr.12519

6. Goldberg, M. V., & Drake, C. G. (2011). LAG-3 in Cancer Immunotherapy. Current topics in microbiology and immunology, 344, 269-278. https://doi.org/10.1007/82_2010_114

Long Name

Lymphocyte-activation Gene 3

Alternate Names

CD223, LAG3

Gene Symbol

LAG3

Additional LAG-3 Products

Product Documents for LAG-3 Antibody (17B4)

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Product Specific Notices for LAG-3 Antibody (17B4)

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Primary Antibodies are guaranteed for 1 year from date of receipt.

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