Human serum-induced expression of E-selectin on porcine aortic endothelial cells in vitro is totally complement mediated

Transplantation. 2001 Dec 27;72(12):1967-73. doi: 10.1097/00007890-200112270-00017.


Background: Whereas complement is a key mediator of hyperacute xenograft rejection, its role in acute vascular rejection (AVR) is a matter of controversy. AVR is associated with de novo synthesis of endothelial cell-derived inflammatory mediators, including the leukocyte-recruiting adhesion molecule E-selectin. Here we investigate the role and mechanism of complement in human serum-induced porcine endothelial cell activation.

Methods: An in vitro xenotransplantation method was designed using porcine aortic endothelial cells stimulated with human serum in microculture wells. E-selectin expression was measured by cell-enzyme immunoassay. Complement inhibitors acting at different levels in the cascade were investigated for their effect on E-selectin expression.

Results: E-selectin was strongly induced by normal human serum but not by heat-inactivated serum. Compstatin, a synthetic C3 inhibitor, markedly reduced human serum-induced E-selectin expression. Purified C1-inhibitor suppressed E-selectin induction completely, indicating activation through the classical or lectin pathway. Furthermore, a monoclonal antibody (mAb) that inhibits cleavage of C5 or another mAb that blocks the function of C7, completely inhibited the expression of serum-induced E-selectin, consistent with the terminal C5b-9 complement complex being the mediator of the endothelial cell activation. Inhibition of the alternative pathway using a novel antifactor D mAb did not reduce E-selectin expression.

Conclusion: Human serum-induced expression of porcine E-selectin is totally complement dependent, induced by a C1-inhibitor regulated pathway and mediated through the terminal complement complex. The data may have implications for therapeutic strategies, particularly of C1-inhibitor and anti-C5 mAb, to protect against endothelial cell activation and subsequent AVR of porcine xenografts.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / pharmacology
  • Aorta / cytology
  • Aorta / metabolism*
  • Aorta / physiology
  • Blood Physiological Phenomena*
  • Cells, Cultured
  • Complement C1 / drug effects
  • Complement C5 / immunology
  • Complement C7 / immunology
  • Complement Inactivator Proteins / pharmacology
  • Complement Membrane Attack Complex / physiology
  • Complement System Proteins / physiology*
  • E-Selectin / drug effects
  • E-Selectin / metabolism*
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / metabolism*
  • Endothelium, Vascular / physiology
  • Humans
  • Peptides, Cyclic / pharmacology
  • Swine / metabolism*


  • Antibodies, Monoclonal
  • Complement C1
  • Complement C5
  • Complement C7
  • Complement Inactivator Proteins
  • Complement Membrane Attack Complex
  • E-Selectin
  • Peptides, Cyclic
  • compstatin
  • Complement System Proteins