Von Willebrand factor targets IL-8 to Weibel-Palade bodies in an endothelial cell line.
Vascular endothelial cells are able to store the chemotactic cytokine interleukin-8 (IL-8) in specialized storage vesicles, Weibel-Palade bodies, together with von Willebrand factor (VWF) and P-selectin. We investigated whether VWF plays a role in the sorting of IL-8 into these organelles. We examined the effect of VWF expression on IL-8 targeting in an endothelial cell line (EC-RF24). This cell line has retained the typical phenotypic characteristics of primary endothelial cells but has lost the capacity to produce VWF in appreciable amounts. EC-RF24 cells were retrovirally transduced with a vector encoding a VWF-green fluorescent protein chimera (VWF-GFP). This approach enables direct visualization of the cellular distribution and secretory behavior of the VWF-GFP hybrid. Expression of VWF-GFP resulted in the generation of Weibel-Palade body-like organelles as shown by the colocalization of VWF-GFP and P-selectin. VWF-GFP expressing EC-RF24 cells also showed significant colocalization of VWF-GFP with IL-8 in these storage vesicles. Live cell imaging revealed that the number of VWF-GFP-containing granules decreased upon cell stimulation. These observations indicate that VWF plays an active role in sequestering IL-8 into Weibel-Palade bodies.
Romani de Wit
Thalia
T
Department of Plasma Proteins and Blood Coagulation, CLB, Plesmanlaan 125, 1066 CX Amsterdam, The Netherlands.
de Leeuw
Hubert P J C
HP
Rondaij
Mariska G
MG
de Laaf
Rozalia T M
RT
Sellink
Erica
E
Brinkman
Herm-Jan
HJ
Voorberg
Jan
J
van Mourik
Jan A
JA
D000911:Antibodies, Monoclonal / Q000378:metabolism; D002402:Cathepsin D / Q000378:metabolism; D002460:Cell Line; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D006801:Humans; D007202:Indicators and Reagents / Q000378:metabolism; D007375:Interleukin-1 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism*; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D019007:P-Selectin / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020302:Weibel-Palade Bodies / Q000378:metabolism*; D014841:von Willebrand Factor / Q000235:genetics / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D007202:Indicators and Reagents; D007375:Interleukin-1; D016209:Interleukin-8; D008164:Luminescent Proteins; D019007:P-Selectin; D011993:Recombinant Fusion Proteins; D014841:von Willebrand Factor; D049452:Green Fluorescent Proteins; D002402:Cathepsin D