Protein / target
T-cell surface glycoprotein CD3 delta chain
Protein at a glance
Biological role
Transmembrane signaling receptor activity
Primary system
Immune system
Strongest disease association
immunodeficiency 19
Therapeutic maturity
Clinically validated target
Druggability
Small molecule
Clinical development
11 approved · 5 in clinical development
Derived from structured UniProt, Open Targets and literature data on this page.
Protein profile
Canonical identity and biological annotation from UniProt.
Function
Part of the TCR-CD3 complex present on T-lymphocyte cell surface that plays an essential role in adaptive immune response. When antigen presenting cells (APCs) activate T-cell receptor (TCR), TCR-mediated signals are transmitted across the cell membrane by the CD3 chains CD3D, CD3E, CD3G and CD247/CD3Z. All CD3 chains contain immunoreceptor tyrosine-based activation motifs (ITAMs) in their cytoplasmic domain. Upon TCR engagement, these motifs become phosphorylated by Src family protein tyrosine kinases LCK and FYN, resulting in the activation of downstream signaling pathways (PubMed:2470098). In addition of this role of signal transduction in T-cell activation, CD3D plays an essential role in thymocyte differentiation. Indeed, participates in correct intracellular TCR-CD3 complex assembly and surface expression. In absence of a functional TCR-CD3 complex, thymocytes are unable to differentiate properly. Interacts with CD4 and CD8 and thus serves to establish a functional link between the TCR and coreceptors CD4 and CD8, which is needed for activation and positive selection of CD4 or CD8 T-cells (PubMed:12215456)
Subcellular location
Domains and Gene Ontology detail (14)Hide
Domains & features
Gene Ontology
- Calpha-beta T cell receptor complex
- Cclathrin-coated endocytic vesicle membrane
- Ccytoplasm
- Cexternal side of plasma membrane
- Cplasma membrane
- CT cell receptor complex
- Fidentical protein binding
- Ftransmembrane signaling receptor activity
- Padaptive immune response
- Palpha-beta T cell activation
- Pcell surface receptor signaling pathway
- Ppositive thymic T cell selection
Biological roles
What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.
View supporting evidenceHide supporting evidence
Immune signalling
- ·Part of the TCR-CD3 complex present on T-lymphocyte cell surface that plays an essential…
- ·alpha-beta T cell receptor complex
- ·T cell receptor complex
- ·adaptive immune response
Synaptic signalling
- ·Translocation of ZAP-70 to Immunological synapse
Kinase signalling
- ·Phosphorylation of CD3 and TCR zeta chains
View underlying pathways (8)Hide underlying pathways
Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.
Interaction neighbourhood
Proteins with the strongest functional or physical association. Node size and line weight reflect STRING confidence; hover or select a partner to inspect one association.
Functional and physical associations from STRING v12.0. Only associations with this protein are drawn — partner-to-partner links are not part of this evidence.
Drugs targeting this protein
Whether each drug engages this protein directly or through a complex, and how many other targets are recorded for it. Direct binders with few recorded targets are listed first.
T cell surface glycoprotein CD3 cross-linking agent
Appears in clinical studies involving acute lymphoblastic leukemia, B-cell acute lymphoblastic leukemia, lymphoid leukemia, neoplasm
ChEMBL mechanism, action type and target identity. Open Targets clinical status and indications.
Translational evidence
Why this target matters therapeutically — disease associations, drugs in development, tractability and safety, from Open Targets.
Strongest genetic associations
Human genetic evidence — the most direct causal link between this target and a disease.
Highest-confidence therapeutic associations
Diseases where a drug acting on this target has already reached clinical development.
Highest overall evidence
Remaining associations by Open Targets' aggregated evidence score.
Show all associationsHide all associations
Open Targets ranks 315 associations for this target and we store the top 10 by aggregated score. The long tail is largely literature co-mention and RNA-expression evidence, not evidence that this target drives those diseases.
Known drugs · 16 total
melanoma
follicular lymphoma · B-cell non-Hodgkin lymphoma · diffuse large B-cell lymphoma
graft versus host disease · acute lymphoblastic leukemia · renal cell carcinoma
acute leukemia of ambiguous lineage · acute myeloid leukemia by FAB classification · hematopoietic and lymphoid cell neoplasm
Ascites · neoplasm · Ascites
diffuse large B-cell lymphoma · neoplasm · diffuse large B-cell lymphoma
acute lymphoblastic leukemia · B-cell acute lymphoblastic leukemia · lymphoid leukemia
follicular lymphoma · neoplasm · follicular lymphoma
follicular lymphoma · neoplasm · high grade B-cell lymphoma
metabolic dysfunction-associated steatohepatitis · type 2 diabetes mellitus · COVID-19
Tractability
Clinical trials
Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein.
Show remaining trials (24)Hide
ClinicalTrials.gov via the drug-target graph.
Forefront confidence
Our own weighting of the evidence behind each disease association. Human genetics and clinical evidence count for most; literature co-mention counts for little, because two entities sharing an abstract is not evidence that one drives the other.
The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the underlying per-type scores are shown above so the calculation can be checked.
What's happening now
Recent activity around this target, drawn from one canonical event stream. Every item is reached through a drug that targets this protein, so each event is news about that drug rather than about the protein directly.
- New publicationCurative outcomes following blinatumomab in adults with minimal residual disease B-cell precursor acute lymphoblastic leukemia.
- New publicationThe BiTE (bispecific T-cell engager) platform: Development and future potential of a targeted immuno-oncology therapy across tumor types.
- New publicationBlinatumomab for minimal residual disease in adults with B-cell precursor acute lymphoblastic leukemia.
- Regulatory approval
Approval: Blincyto (EMA)
Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.