Vascular endothelial cells (EC) are a major target of injury in xenograft rejection and in vascular diseases. The long term objective of this laboratory is to understand mechanisms of injury to EC, especially those caused by complement activation, and to develop approaches to prevent injury. These objectives are pursued by studying xenotransplantation models in which EC injury by the membrane attack complex of complement (MAC) is of paramount importance in graft rejection. We have recently discovered that following activation, porcine EC become resistant to the injurious effects of the MAC. Porcine EC and human complement or blood are used as models for pig-to-human transplantation as the pig is considered a potential donor. We hypothesize that this inducible resistance of porcine EC to the MAC, and possibly to other mediators of damage, results from EC activation, which in turn causes impairment of the EC activation triggered by the MAC. This hypothesis will be tested using models of porcine-to-human xenotransplantation, as follows. 1. We will establish the specificity, scope and mechanisms of protection against xenogeneic injury achieved in EC by stimulation with an alphagalactosyl-specific agonist, the lectin Bandeiraea simplicifolia BS-I. These in vitro studies will determine which of the known proinflammatory effects of the MAC are abrogated in EC, in addition to the lytic action of the MAC. Experiments will also establish whether resistance to damage by NK cells, a known mechanism of xenogeneic injury, also takes place, and if resistance correlates with activation of antiapoptotic genes; the role of alphagal antigen density in the establishment of resistance; the mechanisms of altered MAC structure and function; and the impairment of the activation triggered by the MAC in lectin-treated cells. 2. Because injury to EC in a graft or in vascular diseases occurs under the dynamic influence of blood circulation, studies will be carried out with an isolated porcine kidney perfused ex vivo with human blood. The EC of the organ will be activated to resist injury by exposure to lectin and then subjected to the injurious effects of human blood. Our hypothesis will be evaluated with studies similar to those for the in vitro model. These studies will provide fundamental knowledge of mechanisms that could be manipulated to protect the vascular endothelium when a solid organ xenograft is transplanted into a human. This may potentially contribute to the success of clinical xenotransplantation to meet the need for organ replacement. This knowledge may also be of importance for innovative strategies to control vascular diseases such as arteriosclerosis and vasculitis.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL062195-02
Application #
6184607
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Project Start
1999-08-16
Project End
2002-07-31
Budget Start
2000-08-01
Budget End
2001-07-31
Support Year
2
Fiscal Year
2000
Total Cost
$239,398
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Surgery
Type
Schools of Medicine
DUNS #
168559177
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Benson, Barbara A; Vercellotti, Gregory M; Dalmasso, Agustin P (2015) IL-4 and IL-13 induce protection from complement and melittin in endothelial cells despite initial loss of cytoplasmic proteins: membrane resealing impairs quantifying cytotoxicity with the lactate dehydrogenase permeability assay. Xenotransplantation 22:295-301
Dalmasso, Agustin P; Goldish, Daniel; Benson, Barbara A et al. (2014) Interleukin-4 induces up-regulation of endothelial cell claudin-5 through activation of FoxO1: role in protection from complement-mediated injury. J Biol Chem 289:838-47
Dalmasso, Agustin P (2012) On the intersections of basic and applied research in xenotransplantation. Xenotransplantation 19:137-43
Black, Sylvester M; Benson, Barbara A; Idossa, Damé et al. (2011) Protection of porcine endothelial cells against apoptosis with interleukin-4. Xenotransplantation 18:343-54
Black, Sylvester M; Schott, Megan E; Batdorf, Bjorn H et al. (2010) IL-4 induces protection of vascular endothelial cells against killing by complement and melittin through lipid biosynthesis. Eur J Immunol 40:803-12
Black, S M; Schott, M E; Benson, B A et al. (2008) Interleukin-4 induces lipogenesis in porcine endothelial cells, which in turn is critical for induction of protection against complement-mediated injury. Transplant Proc 40:638-40
Black, Sylvester M; Grehan, John F; Rivard, Andrew L et al. (2006) Porcine endothelial cells and iliac arteries transduced with AdenoIL-4 are intrinsically protected, through Akt activation, against immediate injury caused by human complement. J Immunol 177:7355-63
Grehan, John F; Levay-Young, Brett K; Fogelson, Jeremy L et al. (2005) IL-4 and IL-13 induce protection of porcine endothelial cells from killing by human complement and from apoptosis through activation of a phosphatidylinositide 3-kinase/Akt pathway. J Immunol 175:1903-10
Grehan, John F; Levay-Young, Brett K; Benson, Barbara A et al. (2005) Alpha Gal ligation of pig endothelial cells induces protection from complement and apoptosis independently of NF-kappa B and inflammatory changes. Am J Transplant 5:712-9
Grubbs, Brian C; Benson, Barbara A; Dalmasso, Agustin P (2003) Characteristics of CD59 up-regulation induced in porcine endothelial cells by alphaGal ligation and its association with protection from complement. Xenotransplantation 10:387-97

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