Human CD274 (programmed cell death 1 ligand 1) is a cell membrane protein which is involved in the costimulatory signal, essential for T-cell proliferation and IFNG production in a PDCD1-independent manner. Interaction with PDCD1 inhibits T-cell proliferation by blocking cell cycle progression and cytokine production. Recent data indicated that cancer cells that express PDL1 promote tumor progression through inhibition of PD1-expressing immune effectors. In addition, PDL1 modulates cell-mediated immunity in the infectious disease setting.

Recombinant human CD274 extracellular domain cDNA (19-238 aa, derived from BC074984) was constructed with codon optimization and expressed with a small T7-His-TEV cleavage site Tag (29aa) fusion at its N-terminal and expressed in E. coli as inclusion bodies. The final product was refolded using our unique “temperature shift inclusion body refolding” technology and chromatographically purified.