Product Information
Product name
Human PD-L1/B7-H1, C-His Tag Protein
Catalog No.
HA210954
Predicted molecular mass
26.6 kD
Protein construction description
A DNA sequence encoding the human PD-L1/B7-H1 protein (Q9NZQ7-1) (Phe 19-Arg 238) was expressed with a His tag at the C-terminus.
Accession
Q9NZQ7-1
Protein construction
Source
HEK293
Bio Activity
Testing in progress.
Purity
>95% as determined by SDS-PAGE.
Endotoxin
Less than 1.0 EU per μg by the LAL method.
Formulation
Lyophilized from a 0.2 μm filtered solution of PBS, pH7.4, 5% Trehalose, 5% mannitol.
Species
Human
Background
PD-L1 (programmed-death ligand 1; CD274), is a transmembrane protein constitutionally expressed on a variety of cell types, including antigen presenting cells (dendritic cells and histiocytes) and some non-lymphoid tissues (heart and lung). Binding of PD-L1 to PD-1 (programmed-death 1; CD279) expressed by activated T-cells, inhibits their function, causing negative feedback control of immunological reactions, thus impeding inflammation and autoimmunity. Tumour cells may express PD-L1, which binds to PD-1 allowing cancer cells to evade the attack of T-cells. Blockade of the PD-1/PD-L1 pathway has now shown useful in therapy of multiple cancer types, causing durable tumour regressions in a substantial proportion of otherwise treatment refractory cases of melanoma, and carcinomas of e.g., lung, kidney, and urinary tract. Patients without tumour PD-L1 expression can also derive benefit from blocking agents (studies across multiple cancer types demonstrate a pooled response rate of 48% in patients with PD-L1-positive tumours compared to 15% in PD-L1-negative tumours). Tonsil and placenta can be used as positive and negative tissue controls. However, tonsil is found to be superior to placenta, as tonsil displayes a range of PD-L1 expression levels. Tonsil displayes the following reaction pattern: No staining reaction in the vast majority of lymphocytes including mantle zone and germinal centre B-cells, no staining reaction in superficial epithelial cells, a weak to moderate, typically punctuated membranous staining reaction of the majority of germinal centre macrophages and finally a moderate to strong staining reaction of the majority of epithelial crypt cells.
Usage guide
Shipping
In general, recombinant proteins are provided as lyophilized powder which are shipped with blue ice. Bulk packages of recombinant proteins are provided as frozen liquid which are shipped with dry ice.
Storage
Please avoid repeated freeze-thaw cycles. Samples are stable for up to twelve months from date of receipt at -20℃ to -80℃ It is recommended that aliquot the reconstituted solution to minimize freeze-thaw cycles.
Reconstitution
Reconstitute at 250 μg/ml in sterile water.