Human PD-L1
Programmed cell death ligand 1 (PD-L1) is a protein that plays a crucial role in immune regulation and is a major therapeutic target for cancer immunotherapy.
Human PD-L1
Function
Programmed cell death ligand 1 (PD-L1), also known as CD274 or B7-H1, is a transmembrane protein that serves as a ligand for the immune checkpoint receptor PD-1. PD-L1 is expressed on various cell types including tumor cells, antigen-presenting cells, and some normal tissues. When PD-L1 binds to PD-1 on T cells, it delivers an inhibitory signal that suppresses T cell activation and proliferation, helping to maintain immune homeostasis but also allowing tumors to evade immune surveillance.
Therapeutic Relevance
PD-L1 is one of the most important targets in modern cancer immunotherapy:
- Immune Checkpoint Inhibition: Blocking PD-L1 prevents the inhibitory signal to T cells, allowing them to attack tumor cells
- Biomarker: PD-L1 expression levels are used as a biomarker to predict response to immunotherapy
- Multiple Cancer Types: PD-L1 inhibitors are approved for treating lung cancer, melanoma, bladder cancer, and many other malignancies
- Combination Therapies: Often used in combination with other checkpoint inhibitors or traditional therapies
Target Details
Protein Information
Protein Information
Organism: Homo sapiens (Human) Gene Name: CD274 Alternative Names: B7-H1, PDCD1LG1 Protein Family: B7 family of immune checkpoint proteins
Database References
Database References
UniProt ID: Q9NZQ7 Gene ID: 29126 NCBI Reference: NP_054862.1 Protein Region: Phe 19 - Arg 238
Structural Information
Structural Information
Molecular Weight: ~33 kDa (extracellular domain) Domains: Ig-like V-type domain, Ig-like C2-type domain Key Features: N-linked glycosylation sites, transmembrane domain, cytoplasmic tail PDB Structures: Multiple structures available including complexes with PD-1 and therapeutic antibodies
Expression and Localization
Expression and Localization
Expression Pattern: Constitutive low-level expression on many cell types, upregulated by inflammatory signals Cellular Location: Cell surface (transmembrane protein) Tissue Distribution: Immune cells, epithelial cells, endothelial cells, tumor cells Regulation: Induced by interferons, TNF-α, and other inflammatory cytokines
Applications in Research
Binding Studies
- Antibody Development: Target for therapeutic monoclonal antibodies (pembrolizumab, nivolumab, etc.)
- Binding Kinetics: Critical for understanding drug-target interactions
- Specificity Studies: Important for developing selective inhibitors
Drug Development
- Immunotherapy: Primary target for checkpoint inhibitor drugs
- Combination Studies: Investigating synergistic effects with other therapies
- Resistance Mechanisms: Understanding how tumors develop resistance to PD-L1 blockade
Biomarker Development
- Companion Diagnostics: PD-L1 expression as a predictive biomarker
- Patient Stratification: Identifying patients likely to respond to immunotherapy
- Monitoring: Tracking treatment response and disease progression
PD-L1 is one of our most popular binding targets due to its central role in cancer immunotherapy. Our platform has been used to develop and optimize numerous PD-L1-binding proteins for therapeutic and diagnostic applications.