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APC Human PD1 (CD279) Protein (C-Fc)

CHO cells transfected with either PD1 CAR or Mock plasmid were stained with APC conjugated PD1 (C-Fc) protein at 1ug_test

Cat #	Size	Price	Quantity
803303	25 ug	$245
803304	100 ug	$595

Bulk/Custom

Product Details

Application	Flow Cytometry
Format	Liquid, APC
Expression Host	HEK293
Target Name	PD1, PDCD1, CD279, SLEB2
Species	Human
Sources	Human PD-1 protein (NP_005009.2) (Leu25-Gln167) with C-terminus Fc tag is expressed in HEK293 cells and conjugated to APC
Accession Number	Q15116
Molecular Weight	The protein has a predicted molecular weight of 19 kDa. Under DTT-reducing conditions, it migrates at approximately 25-30 kDa on SDS-PAGE prior to conjugation.
Affinity Tag	C-Fc
Regulatory Status	RUO
Formulation	1xPBS buffer, pH7.4, 0.09% NaN3 with a carrier protein
Endotoxin level	Not tested
Protein Concentration	25µg size is bottled at 0.1mg/mL concentration. 100 µg size is bottled at lot specific concentration.
Storage and Handling	Briefly centrifuge the vial upon receipt. An unopened vial may be stored at 2–8°C for up to six months.
Research Areas	Immune Checkpoints, Activated T cells, Cancer Immunology, Tregs, Tfh cells, Activated B cells

Background Information

CD279, also known as Programmed Cell Death Protein 1 (PD-1), is a crucial immune checkpoint receptor that regulates T cell activation and prevents autoimmunity. This transmembrane protein plays a pivotal role in maintaining immune homeostasis by delivering inhibitory signals that dampen excessive immune responses.

PD-1 is a type I transmembrane glycoprotein belonging to the immunoglobulin superfamily. It contains an extracellular immunoglobulin variable (IgV)-like domain, a transmembrane region, and an intracellular tail with two tyrosine-based signaling motifs: an immunoreceptor tyrosine-based inhibitory motif (ITIM) and an immunoreceptor tyrosine-based switch motif (ITSM). When engaged, these motifs recruit phosphatases that inhibit T-cell receptor signaling, effectively suppressing T-cell activation, proliferation, and cytokine production.

PD-1 interacts with two primary ligands: PD-L1 (B7-H1/CD274) and PD-L2 (B7-DC/CD273). PD-L1 is widely expressed on various cell types, including tumor cells, antigen-presenting cells, and non-hematopoietic tissues, while PD-L2 expression is more restricted to antigen-presenting cells. These ligand-receptor interactions serve as critical brakes on immune responses. In cancer, tumor cells exploit the PD-1/PD-L1 pathway to evade immune surveillance. By upregulating PD-L1 expression, tumors effectively "turn off" infiltrating T-cells, preventing effective anti-tumor immunity. This mechanism contributes to tumor progression and immune escape across multiple cancer types.

The discovery of PD-1's role in cancer has revolutionized oncology through immune checkpoint inhibitors. Monoclonal antibodies targeting PD-1 (pembrolizumab, nivolumab) or PD-L1 (atezolizumab, durvalumab) block this inhibitory pathway, reinvigorating anti-tumor T-cell responses. These therapies have demonstrated remarkable success in treating melanoma, non-small cell lung cancer, renal cell carcinoma, and numerous other malignancies, fundamentally transforming cancer treatment paradigms and offering durable responses in previously untreatable cancers.

Frequently Asked Questions

How is a fluorescence labeled recombinant protein different from a labeled antibody for the same target?

A labeled protein (e.g., a fluorescent ligand or receptor domain) binds its natural counter-receptor or binding partner directly, making it useful for functional binding assays, competition/blocking studies, and receptor occupancy measurements — whereas an antibody typically binds a specific epitope regardless of the protein's natural binding activity. Choose the labeled protein format when you need to assess biologically relevant binding interactions rather than simple target detection.

Can these proteins be used in flow cytometry, and are they compatible with other panel reagents?

Yes, fluorescence labeled proteins are commonly used in flow cytometry panels to detect receptor expression or ligand binding on live cells, and are designed to be compatible with standard antibody panels. As with any multicolor panel, confirm spectral compatibility and run proper compensation controls when combining labeled proteins with labeled antibodies.

What controls should I use with fluorescence labeled recombinant proteins?

Recommended controls include an unlabeled/unconjugated version of the same protein (for competition/blocking controls), an irrelevant labeled protein of the same conjugate as a background control, and standard unstained/FMO controls for gating. Species- or format-matched controls are noted on the product page where available.

What applications are these proteins validated for?

Common applications include receptor binding assays, flow cytometry-based ligand-receptor studies, ELISA-based detection, and blocking/competition assays to study receptor occupancy or antagonist activity. Specific validated applications and recommended usage concentrations vary by product and are detailed on the individual product page.

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

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