GLOSSARY
P
P-selectin (CD62P) #
Alternative names: GMP-140, PADGEM
In humans and in mice, P-selectin can be found on the surface of: platelets and endothelial cells
Ligands: CD162 (PSGL-1)
Associated molecules: CD24
Function: cell adhesion, platelet aggregation
Additional information: P-selectin is also known as CD62P. CD62P is constitutively expressed in platelet precursors and endothelial cells. It is stored in granules until activation of these cells leads to surface expression. CD62P expression is critical for homing leukocytes to inflamed areas. Surface CD62P binds to CD162 on leukocytes that flow past the infected area at high velocity, capturing the leukocytes and mediating their tethering and rolling on activated endothelium in the initial states of inflammation. CD62P on the surface of platelets facilitates platelet aggregation. In cancer, CD62P mediates metastasis.
PD-L2 (CD273) #
Alternative names: B7DC, MGC142238, bA574F11.2, MGC142238, MGC142240, bA574F11.2, PDCD1LG2
In humans and in mice, PD-L2 can be found on the surface of: T cells, dendritic cells, macrophages/monocytes.
Ligands: PD-1 (CD279)
Function: costimulation, inhibition, regulation of T cell proliferation
Additional information: PD-L2 is also known as CD273. CD273 interacts with CD279 to inhibit T cell proliferation and cytokine production, playing an important role in establishing immune tolerance and limiting autoimmunity. CD273 has also been shown to have immune-activating effects by inducing IL-12 production in dendritic cells.
pDC #
A subset of dendritic cells (DCs) derived from haematopoietic stem cells. Plasmacytoid DCs (pDCs) detect and respond rapidly to viral infections to produce high quantities of type I and type III interferons and cytokines, and may play a role in chronic infections. Conversely, pDC may also play a role in autoimmune diseases. The ability of pDC to sense self-nucleic acids and to produce type I interferon has been implicated in the pathogenesis of psoriasis and systemic lupus erythematosus. pDC have also been shown to induce T cell tolerance, and perhaps contribute to tumor progression.
PSGL-1 (CD162) #
Alternative names: P-Selectin-IgG fusion protein (in mice)
In humans and in mice, PSGL-1 can be found on the surface of: T cells, B cells, monocytes/macrophages, stem cells, granulocytes
Ligands: E- (CD62E), P- (CD62P) and L-(CD62L) selectins
Function: cell adhesion, host–virus interaction
Additional information: P-selectin glycoprotein ligand (PSGL-1) is also known as CD162. CD162 is expressed on all myeloid and lymphoid lineages. Its expression level differs between cell types. Myeloid cells constitutively express functioning CD162, while T cells express a modified form that must be activated during T cell activation. CD162 plays a crucial role in leukocyte capture at infected tissue by mediating the tethering and rapid rolling of leukocytes on activated endothelium in the initial stages of inflammation. As the leukocyte flows at high velocity past the tissue, CD162 binds with E-, P- and L-selectins presented on the surface of the endothelial cell, which preempts attachment, rolling, and subsequent transmigration of the leukocyte into the tissue, where it may exert its effector functions.
Further reading:Pyroptosis #
A cell death program characterized by lysis and the release of pro-inflammatory signals that elicit inflammatory responses from neighboring cells. Pyroptosis can be set off by pathological stimulation, including microbial infection, stroke, heart attack, and cancer. Intracellular danger signals trigger the formation of the inflammasome, activation of caspases, proinflammatory cytokines, and pore-forming gasdermins in the affected cells. Assembled gasdermin pores in the cell membrane then facilitate pyroptosis of the cell by water influx, cell membrane rapture, and the release of cytokines and other danger signals.
