Platelet-mediated interactions with vascular and circulating cells (WP4462)

This pathway describes platelet-mediated interactions with vascular or circulating cells. It is adapted from figure 2 in [ Koupenova et al], in collaboration with Dr. Milka Koupenova. Platelets interact with endothelial and immune cells in the circulation, and control the response to microbes, inflammatory stimuli, and vessel damage. Through their TLRs or inflammatory signals, platelets can change their surface expression and release their granule content and in that way interact with different immune cells. Platelets form heterotypic aggregates with other immune cells and initiate innate immune responses in the presence of TLR agonists and viruses (encephalomyocarditis virus, coxsackievirus B, dengue, flu and HIV). Platelets can also interact with dendritic cells through P-selectin, and activate them to become antigen-presenting through their CD154. Platelets engage the adaptive immune response by releasing their granule content which leads to IgG production and control of T-cell function. Similarly, platelets are able to activate the endothelium, make it more permeable, and mediate leukocyte trafficking to the inflamed endothelium. Description is adapted from Koupenova et al.
last edited


Khanspers, DeSl, and Egonw

Cited In


Homo sapiens



Disease Ontology: thrombosis

Cell Type Ontology: platelet

Pathway Ontology: hemostasis pathway


Label Type Compact Identifier
SELE GeneProduct ensembl:ENSG00000007908
P-selectin Protein uniprot:P16109
TLR2 Protein uniprot:O60603
IL1B GeneProduct ensembl:ENSG00000125538
CD40 Protein uniprot:P25942
TLR4 Protein uniprot:O00206
TLR7 Protein uniprot:B2R9N9
CD40 GeneProduct ensembl:ENSG00000101017
VCAM1 GeneProduct ensembl:ENSG00000162692
ICAM1 GeneProduct ensembl:ENSG00000090339
PF4 GeneProduct ensembl:ENSG00000163737
Serotonin Metabolite chebi:28790
CCL5 GeneProduct ensembl:ENSG00000271503
TGFB1 GeneProduct ensembl:ENSG00000105329
CD40LG GeneProduct ensembl:ENSG00000102245
PSGL1 Protein uniprot:Q14242
P-selectin Protein uniprot:P16109
PSGL1 Protein uniprot:Q14242
PSGL1 Protein uniprot:Q14242
CD40-L Protein uniprot:P29965
TLR4 Protein uniprot:O00206
IL1B GeneProduct ensembl:ENSG00000125538
CCL2 GeneProduct ensembl:ENSG00000108691
TGFB2 GeneProduct ensembl:ENSG00000092969
TGFB3 GeneProduct ensembl:ENSG00000119699


  1. Koupenova M, Clancy L, Corkrey HA, Freedman JE. Circulating Platelets as Mediators of Immunity, Inflammation, and Thrombosis. Circ Res. 2018 Jan 19;122(2):337–51. PubMed Europe PMC Scholia