PD-L1 Protein, Human (HEK293, His)

PD-L1 Protein is an important immunoregulatory molecule and a member of the B7 superfamily. As the primary ligand of PD-1, PD-L1 Protein can bind to PD-1 to inhibit T-cell activation, proliferation, and cytokine secretion, and induce T-cell apoptosis. PD-L1 Protein plays a key role in tumor immune escape and immune homeostasis regulation. PD-L1 Protein, Human (HEK293, His) is a recombinant PD-L1 protein expressed by HEK293 with a C-His His tag^[1][2][3].

PD-L1 is a 33 kDa type I transmembrane glycoprotein containing 290 amino acids, with Ig- and IgC domains in its extracellular region. Under normal conditions, PD-L1 maintains immune homeostasis by binding to PD-1 on the surface of T cells to inhibit excessive immune responses. In tumors, abnormally high expression of PD-L1 binds to PD-1 to suppress T cell function, thereby helping tumors evade immune surveillance. PD-L1 may also be involved in tumor angiogenesis and microenvironmental remodeling. Currently, as a core target, PD-L1 has driven the development of tumor immune checkpoint inhibitor therapy^[1][2][3].

1. 2 µg/mL (100 µL/well) of immoblized recombinant human PD-L1-His can bind human PD-1-Fc with a linear range of 24-390 ng/mL.
2. Measured by its ability to inhibit anti-CD3-induced proliferation of stimulated CTLL-2 mouse cytotoxic T cells. The ED₅₀ this effect is 1.012 μg/mL, corresponding to a specific activity is 988.14 units/mg.
3. Measured by its binding ability in a functional ELISA. Immobilized Human PD-L1 at 1 μg/mL (100 μL/well) can bind Biotinylated Human PD-1 (HY-P7396). The ED₅₀ for this effect is <0.5 μg/mL.
4. Immobilized Anti-Human PDL1 mAb at 2 μg/mL (100 μL/well) can bind Human PD-L1. The ED₅₀ of Human PD-L1 is 1-10 ng/mL.

• 
  Measured by its ability to inhibit anti-CD3-induced proliferation of stimulated CTLL-2 mouse cytotoxic T cells. The ED₅₀ this effect is 1.012 μg/mL, corresponding to a specific activity is 988.14 units/mg.
• 
  PD-1 Protein, Human (HY-P7395) captured on CM5 Chip can bind PD-L1 Protein, Human (HEK293,His) with an affinity constant of 1.86E-7 M as determined in SPR assay (Biacore 8K).

Human

HEK293

C-His

Q9NZQ7-1 (F19-T239)

29126  [NCBI]

Partial

FTVTVPKDLYVVEYGSNMTIECKFPVEKQLDLAALIVYWEMEDKNIIQFVHGEEDLKVQHSSYRQRARLLKDQLSLGNAALQITDVKLQDAGVYRCMISYGGADYKRITVKVNAPYNKINQRILVVDPVTSEHELTCQAEGYPKAEVIWTSSDHQVLSGKTTTTNSKREEKLFNVTSTLRINTTTNEIFYCTFRRLDPEENHTAELVIPELPLAHPPNERT

Approximately 35-40 kDa, based on SDS-PAGE under reducing condition, due to the glycosylation.

• 
  ≥ 95%, as determined by reducing SDS-PAGE.

Lyophilized powder

1.Lyophilized from a 0.2 μm filtered solution of 20 mM PB, 150 mM NaCl, pH 7.4.
2.Lyophilized from a 0.2 μm filtered solution of 20 mM PB, 4% mannitol, 0.02% Tween 80, pH 7.4.
Please refer to the lot-specific COA for specific buffer information.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O. For long term storage it is recommended to add a carrier protein (0.1% BSA, 5% HSA, 10% FBS or 5% Trehalose).

Stored at -20°C for 2 years from date of receipt. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.

• [1]. Chemnitz JM, et al. SHP-1 and SHP-2 associate with immunoreceptor tyrosine-based switch motif of programmed death 1 upon primary human T cell stimulation, but only receptor ligation prevents T cell activation. J Immunol. 2004 Jul 15;173(2):945-54.  [Content Brief]

  [2]. Han Y, et al. PD-1/PD-L1 pathway: current researches in cancer. Am J Cancer Res. 2020 Mar 1;10(3):727-742.  [Content Brief]

  [3]. Kythreotou A, et al. PD-L1. Journal of clinical pathology, 2018, 71(3): 189-194.