PE Anti-Human CD223 (LAG-3) Antibody

Product Details


CloneRelatlimab
ApplicationFlow Cytometry
ReactivityHuman
FormatPE
Target NameCD223, LAG3, LAG-3, lymphocyte-activation gene-3
IsotypeHuman IgG4
Antibody TypeMonoclonal
Regulatory StatusRUO
FormulationPhosphate-buffered solution, pH 7.2, containing 0.09% sodium azide and 0.2% (w/v) BSA
Protein ConcentrationSupplied at a lot-specific concentration.
Storage&HandlingThe antibody solution should be stored undiluted between 2°C and 8°C, and protected from prolonged exposure to light. Do not freeze.
Recommended UsageFor flow cytometric staining, it is recommended to use 5 µL of this reagent per 0.5-1.0 million cells in a 100 µL volume. Optimal reagent performance should be determined by titration for each specific application. PE has an excitation max at 565 nm and an emission max at 575 nm.
Excitation LaserBlue Laser (488 nm) Green/Yellow laser (532/561nm)
Research AreasT cells, Tregs, Activated NK cells, Immune Checkpoints, Exhaustion
See All FormatsClone Relatlimab

Background Information


Human CD223 (LAG-3) is an inhibitory immune checkpoint receptor expressed on activated T cells, regulatory T cells, NK cells, and dendritic cells. It is a type I transmembrane glycoprotein of the immunoglobulin superfamily with four extracellular Ig-like domains, a single transmembrane region, and a cytoplasmic tail containing inhibitory motifs including KIEELE. CD223 is upregulated after T-cell receptor activation and limits immune responses to maintain peripheral tolerance. It binds MHC class II with high affinity, competing with CD4, and also interacts with fibrinogen-like protein 1 (FGL1), contributing to immune regulation in tumor environments and immune modulation.

CD223 plays a key role in immune evasion in cancer and chronic infection by promoting T-cell exhaustion and reducing cytokine production, proliferation, and cytotoxic function. It is frequently co-expressed with PD-1 on exhausted tumor-infiltrating lymphocytes. While important for preventing autoimmunity, sustained signaling suppresses anti-tumor immunity and supports tumor progression. It is also upregulated during chronic viral infection due to persistent antigen stimulation making it a major target in immunotherapy strategies and ongoing clinical research efforts.

Relatimab is an investigational monoclonal antibody targeting CD223 (LAG-3) that blocks ligand binding to restore T-cell activity. By inhibiting interactions with MHC-II and FGL1, it reduces T-cell exhaustion and enhances anti-tumor responses. It is studied in oncology, often combined with PD-1/PD-L1 inhibitors to improve immune activation and clinical outcomes in cancer therapy within current immunotherapy development strategies and trials ongoing.

Isotype Control


PE Human IgG4 Isotype Control Antibody

Data Sheets


PE Anti-Human CD223 (LAG-3) Antibody TDS

Related Protocols


Flow Cytometry Protocol

Frequently Asked Questions


How do I determine the optimal antibody concentration/titer for my experiment?
We recommend titrating each new antibody lot on your own cell type and instrument, since optimal concentration depends on cell density, target expression level, and cytometer sensitivity. Suggested starting dilutions or test sizes (e.g., µg or µl per 10^6 cells) are provided on the product page as a starting reference point, not a fixed requirement.

Can these antibodies be used for intracellular or intranuclear staining, or only surface staining?
Intended use (surface, intracellular, or both) is specified per product, indicated under Application. The appropriate Related Protocol is linked for each product. If you need to detect both surface and intracellular markers in the same panel, confirm each antibody's compatibility with your fixation/permeabilization protocol before combining them.

What controls should I use alongside these antibodies?
Matched isotype controls (same host species, isotype, and conjugate) are available for most clones to help distinguish specific binding from background/non-specific staining and are linked on each product page. Unstained, single-color compensation, and fluorescence-minus-one (FMO) controls are also recommended, especially for multicolor panel design.

Can I combine InnoCyto Flow Cytometry antibodies into a multicolor panel?
Yes — antibodies across our catalog are designed to be panel-compatible, and conjugate options are offered specifically to support multiplexing. When building a panel, pair bright fluorophores with low-expression targets, avoid excessive spectral overlap, and confirm compensation is set up correctly for your specific fluorochrome combination. Use our Panel Builder to simplify the process.

Have a product or application question? Consult our FAQs or contact us.