The lack of Neu5Gc expression attenuated erythrocyte loss but did not prevent profound early onset thrombocytopenia or platelet activation, although TXB2 levels were decreased in the presence of Neu5GcKO.

ABSTRACT. Recent years have seen a proliferation of methods leading to successful organ decellularization. In this experiment we examine the feasibility of a decellularized liver construct to support growth of functional multilineage cells. Bio-chamber systems were used to perfuse adult rat livers with 0.1% SDS for 24 hours yielding decellularized liver scaffolds. Initially, we recellularized liver scaffolds using a human tumor cell line (HepG2, introduced via the bile duct). Subsequent studies were performed using either human tumor cells co-cultured with human umbilical vein endothelial cells (HUVECs, introduced via the portal vein) or rat neonatal cell slurry (introduced via the bile duct). Bio-chambers were used to circulate oxygenated growth medium via the portal vein at cholangiocytes was verified by CK-7 positivity. Quantitative albumin measurement from the grafts showed increasing albumin levels after seven days of perfusion. Graft albumin production was higher than that observed in traditional cell culture. This data shows that rat liver scaffolds support human cell ingrowth. The scaffold likewise supported the engraftment and survival of neonatal rat liver cell slurry. Recellularization of liver scaffolds thus presents a promising model for functional liver engineering.

Selectin blockade may be useful as part of an integrated strategy to prevent neutrophil-mediated organ xenograft injury, especially during the early time points following reperfusion.

Background Specific blockade of T cell costimulation pathway is a promising immunomodulatory approach being developed to replace our current clinical immunosuppression therapies. The goal of this study is to compare results associated with 3 monoclonal antibodies directed against the CD40/CD154 T cell costimulation pathway. Methods Cynomolgus monkey heterotopic cardiac allograft recipients were treated with either IDEC-131 (humanized αCD154, n=9), 5C8H1 (mouse-human chimeric αCD154, n=5), or 2C10R4 (mouse-rhesus chimericαCD40, n=6) monotherapy using a consistent, comparable dosing regimen for 3 months after transplant. Results Relative to the previously reported IDEC-131 treated allografts, median survival time (MST 35±31 days) was significantly prolonged in both 5C8H1 (142±26, p<0.002) and 2C10R4 (124±37, p<0.020) treated allografts. IDEC-131 treated grafts had higher CAV severity scores during treatment relative to either 5C8H1 (p=0.008) or 2C10R4 (p=0.0002). Both 5C8H1(5 of 5 animals, p=0.02) and 2C10R4 (6/6, p=0.007), but not IDEC-131 (2/9), completely attenuated IgM antidonor alloAb production during treatment;5C8H1 (5/5) more consistently attenuated IgG alloAb production compared to 2C10R4 (4/6) and IDEC-131 (0/9). All evaluable explanted grafts experienced antibody-mediated rejection. Only 2C10R4 treated animals exhibited a modest, transient drop in CD20+ lymphocytes from baseline at d14 after transplant (-457±152 cells/μL) compared to 5C8H1 treated animals (16±25, p=0.037), and the resurgent B cells were primarily of a naïve phenotype. Conclusion In this model, CD154/CD40 axis blockade using IDEC-131 is an inferior immunomodulatory treatment than 5C8H1 or 2C10R4, which have similar efficacy to prolong graft survival and to delay CAV development and antidonor alloAb production during treatment.

Supplemental digital content is available in the text.