TY - JOUR
T1 - Porcine extrahepatic vascular endothelial asialoglycoprotein receptor 1 mediates xenogeneic platelet phagocytosis in vitro and in human-to-pig ex vivo xenoperfusion
AU - Bongoni, Anjan K.
AU - Kiermeir, David
AU - Denoyelle, Julie
AU - Jenni, Hansjörg
AU - Burlak, Christopher
AU - Seebach, Jörg D.
AU - Vögelin, Esther
AU - Constantinescu, Mihai A.
AU - Rieben, Robert
N1 - Publisher Copyright:
© Wolters Kluwer Health, Inc.
PY - 2015/4/1
Y1 - 2015/4/1
N2 - Asialoglycoprotein receptor-1 (ASGR1)mediates capture and phagocytosis of platelets in pig-to-primate liver xenotransplantation. However, thrombocytopenia is also observed in xenotransplantation or xenoperfusion of other porcine organs than liver. We therefore assessed ASGR1 expression as well as ASGR1-mediated xenogeneic platelet phagocytosis in vitro and ex vivo on porcine aortic, femoral arterial, and liver sinusoidal endothelial cells (PAEC/PFAEC/PLSEC). Methods. Porcine forelimbs were perfused with whole, heparinized human or autologous pig blood. Platelets were counted at regular intervals. Pig limb muscle and liver, as well as PAEC/PFAEC/PLSEC, were characterized for ASGR1 expression. In vitro, PAEC cultured on microcarrier beads and incubated with non-anticoagulated human blood were used to study binding of human platelets and platelet-white blood cell aggregation. Carboxyfluorescein diacetate succinimidyl ester-labeled human platelets were exposed to PAEC/PFAEC/PLSEC and analyzed for ASGR1-mediated phagocytosis. Results. Human platelet numbers decreased from 102 ± 33 at beginning to 13 ± 6 × 103/μL (P < 0.0001) after 10 minutes of perfusion, whereas no significant decrease of platelets was seen during autologous perfusions (171 ± 26 to 122 ± 95 × 103/μL). The PAEC, PFAEC, and PLSEC all showed similar ASGR1 expression. In vitro, no correlation was found between reduction in platelet count and platelet-white blood cell aggregation. Phagocytosis of human carboxyfluorescein diacetate succinimidyl ester-labeled platelets by PAEC/PFAEC/PLSEC peaked at 15 minutes and was inhibited (P < 0.05 to P < 0.0001) by rabbit anti-ASGR1 antibody and asialofetuin. Conclusions. The ASGR1 expressed on aortic and limb arterial pig vascular endotheliumplays a role in binding and phagocytosis of human platelets. Therefore, ASGR1 may represent a novel therapeutic target to overcome thrombocytopenia associated with vascularized pig-toprimate xenotransplantation.
AB - Asialoglycoprotein receptor-1 (ASGR1)mediates capture and phagocytosis of platelets in pig-to-primate liver xenotransplantation. However, thrombocytopenia is also observed in xenotransplantation or xenoperfusion of other porcine organs than liver. We therefore assessed ASGR1 expression as well as ASGR1-mediated xenogeneic platelet phagocytosis in vitro and ex vivo on porcine aortic, femoral arterial, and liver sinusoidal endothelial cells (PAEC/PFAEC/PLSEC). Methods. Porcine forelimbs were perfused with whole, heparinized human or autologous pig blood. Platelets were counted at regular intervals. Pig limb muscle and liver, as well as PAEC/PFAEC/PLSEC, were characterized for ASGR1 expression. In vitro, PAEC cultured on microcarrier beads and incubated with non-anticoagulated human blood were used to study binding of human platelets and platelet-white blood cell aggregation. Carboxyfluorescein diacetate succinimidyl ester-labeled human platelets were exposed to PAEC/PFAEC/PLSEC and analyzed for ASGR1-mediated phagocytosis. Results. Human platelet numbers decreased from 102 ± 33 at beginning to 13 ± 6 × 103/μL (P < 0.0001) after 10 minutes of perfusion, whereas no significant decrease of platelets was seen during autologous perfusions (171 ± 26 to 122 ± 95 × 103/μL). The PAEC, PFAEC, and PLSEC all showed similar ASGR1 expression. In vitro, no correlation was found between reduction in platelet count and platelet-white blood cell aggregation. Phagocytosis of human carboxyfluorescein diacetate succinimidyl ester-labeled platelets by PAEC/PFAEC/PLSEC peaked at 15 minutes and was inhibited (P < 0.05 to P < 0.0001) by rabbit anti-ASGR1 antibody and asialofetuin. Conclusions. The ASGR1 expressed on aortic and limb arterial pig vascular endotheliumplays a role in binding and phagocytosis of human platelets. Therefore, ASGR1 may represent a novel therapeutic target to overcome thrombocytopenia associated with vascularized pig-toprimate xenotransplantation.
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U2 - 10.1097/TP.0000000000000553
DO - 10.1097/TP.0000000000000553
M3 - Article
C2 - 25675194
AN - SCOPUS:84930146209
SN - 0041-1337
VL - 99
SP - 693
EP - 701
JO - Transplantation
JF - Transplantation
IS - 4
ER -