|CD273||PDCD1LG2 (programmed cell death 1 ligand 2), B7-DC, PD-L2, PDCG1L2|
|Molecule Type||Antigen Expression||Molecular Weight|
Min / Max
|Non-lineage Restricted Molecule|
Type 1 glycoprotein
|25 / 25|
|CD273 is expressed on dendritic cells, macrophages, activated monocytes and T cells. Upregulation by IFN-γ stimulation occurs in monocytes and induced on dendritic cells grown from peripheral blood mononuclear cells with CSF2 and IL-4. Expression is high in heart, placenta, pancreas, lung and liver, but is weak in spleen, lymph nodes and thymus. It is higly expressed in primary mediastinal B-cell lymphoma cell lines and Hodgkin's lymphoma cell lines.|
|MOLECULAR FAMILY NAME: Belongs to the immunoglobulin gene family. |
CD273 is a single-pass type-1 254 aa glycoprotein. It contains a 19 aa signal sequence, a 201 aa extracellular domain which contains an Ig-like C2-type domain, an Ig-like V-type domain and 5 potential N-linked glycosylation sites, a 21 aa transmembrane domain and a 32 aa cytoplasmic domain. It is a member of the B7 family of costimulatory molecules.
Alternative splicing yields 3 different isoforms. CD273 is found on the plasma membrane (isoform 1). Isoform 2 consists of 183 aa and lacks residues 121-211 and is not expressed at the cell surface but is associated with the intracellular membrane. Isoform 3 comprises 182 residues and bears a delition of residues 183-273 and significant amino acid sequence variation between 121 and 182 and is probably soluble.
POST-TRANSLATIONAL MODIFICATION: No information.
|LIGANDS AND MOLECULE ASSOCIATED WITH CD273|
CD273 binds CD279 (PD1).
|CD273 costimulates the proliferation of T cells, principally CD4+ T cells and mediates IFN-γ production. Several studies have provided evidence that the costimulatory functions of CD273 are unrelated to CD279 (PD-1) binding and are mediated by another as yet unidentified receptor but is a second ligand for CD279. Ligation of CD273 by anti-CD273 IgM enhances activation of dendritic cells and augments dendritic cell stimulation of T cell responses. This indicates CD273 is capable of signaling into the dendritic cell. CD273 can act as a coinhibitor of the T cell function when it interacts with CD279. A recent study has shown that T cell associated CD273 can suppress the proliferation of allo-antigen-specific T cells and IFN-γ and IL-2 production via CD279. Dendritic cells purified from CD273 null mice have a diminished capacity to stimulated T cell responses to nominal and allogenetic antigens. Involvement in the costimulatory signal is essential for T lymphocyte proliferation and IFN-γ production in a CD273-independent manner. Interaction with CD273 inhibits T cell proliferation by blocking cell cycle progression and cytokine production.|
BIOCHEMICAL ACTIVITY: No information.
DISEASE RELEVANCE AND FUNCTION OF CD273 IN INTACT ANIMAL
CD273 expression is a useful marker to distinguish primary mediastinal B-cell lymphoma from other diffuse large B-cell lymphomas.
PROTEINS AND DNA ELEMENTS WHICH REGULATE TRANSCRIPTION OF CD273: No information.
SUBSTRATES: No information.
ENZYMES WHICH MODIFY CD273: No information.
For further information see Brown, J. A. et al (2003) J. Immunol. 170: 1257-1266.
Database accession numbers
Revised June 25, 2008