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Unlabelled: Ischemia-reperfusion injury (IRI) is a major limiting event for successful liver transplantation, and CD4+ T cells and invariant natural killer T (iNKT) cells have been implicated in promoting IRI. We hypothesized that hepatic overexpression of CD39, an ectonucleotidase with antiinflammatory functions, will protect liver grafts after prolonged cold ischemia. CD39-transgenic (CD39tg) and wildtype (WT) mouse livers were transplanted into WT recipients after 18 hours cold storage and pathological analysis was performed 6 hours after transplantation. Serum levels of alanine aminotransferase and interleukin (IL)-6 were significantly reduced in recipients of CD39tg livers compared to recipients of WT livers. Furthermore, less severe histopathological injury was demonstrated in the CD39tg grafts. Immune analysis revealed that CD4+ T cells and iNKT cells were significantly decreased in number in the livers of untreated CD39tg mice. This was associated with a peripheral CD4+ T cell lymphopenia due to defective thymocyte maturation. To assess the relative importance of liver-resident CD4+ T cells and iNKT cells in mediating liver injury following extended cold preservation and transplantation, WT mice depleted of CD4+ T cells or mice genetically deficient in iNKT cells were used as donors. The absence of CD4+ T cells, but not iNKT cells, protected liver grafts from early IRI., Conclusion: Hepatic CD4+ T cells, but not iNKT cells, play a critical role in early IRI following extended cold preservation in a liver transplant model., (Copyright © 2012 American Association for the Study of Liver Diseases.)

Background: We investigated whether graft produced anti-human CD2, mediated by adenovirus (Adv) transduction of pig neonatal islet cell clusters (pNICC), would protect xenografts in a humanized mouse model from immune attack and whether such immunosuppression would remain local., Methods: A mouse anti-human CD2 Ab (CD2hb11) previously generated by us was genetically engineered to produce chimeric and humanized versions. The three forms of CD2hb11 were named dilimomab (mouse), diliximab (chimeric) and dilizumab (humanized). All 3 forms of CD2hb11 Ab were tested for their ability to bind CD3(+) human T cells and to inhibit a human anti-pig xenogeneic mixed lymphocyte reaction (MLR). They were administered systemically in a humanized mouse model in order to test their ability to deplete human CD3(+) T cells and whether they induced a cytokine storm. An adenoviral vector expressing diliximab was generated for transduction of pNICC. Humanized mice were transplanted with either control-transduced pNICC or diliximab-transduced pNICC and human T cells within grafts and spleens were enumerated by flow cytometry., Results: Dilimomab and diliximab inhibited a human anti-pig xenogeneic response but dilizumab did not. All 3 forms of CD2hb11 Ab bound human T cells in vitro though dilimomab and diliximab exhibited 300-fold higher avidity than dilizumab. All 3 anti-CD2 Abs could deplete human CD3(+) T cells in vivo in a humanized mouse model without inducing upregulation of activation markers or significant release of cytokines. Humanized mice transplanted with diliximab-transduced pNICC afforded depletion of CD3(+) T cells at the graft site leaving the peripheral immune system intact., Conclusions: Local production of a single Ab against T cells can reduce graft infiltration at the xenograft site and may reduce the need for conventional, systemic immunosuppression., (© 2013 John Wiley & Sons A/S.)

We report here our experience regarding the production of double or homozygous Gal knockout (Gal KO) pigs by breeding and somatic cell nuclear transfer (SCNT). Large White x Landrace female heterozygous Gal KO founders produced using SCNT were mated with Hampshire or Duroc males to produce a F1 generation. F1 heterozygous pigs were then bred to half-sibs to produce a F2 generation which contained Gal KO pigs. To determine the viability of mating Gal KO pigs with each other, one female F2 Gal KO pig was bred to a half-sib and subsequently a full-sib Gal KO. F1 and F2 heterozygous females were also mated to F2 Gal KO males. All three types of matings produced Gal KO pigs. To produce Gal KO pigs by SCNT, heterozygous F1s were bred together and F2 fetuses were harvested to establish primary cultures of Gal KO fetal fibroblasts. Gal KO embryos were transferred to five recipients, one of which became pregnant and had a litter of four piglets. Together our results demonstrate that Gal KO pigs can be produced by breeding with each other and by SCNT using Gal KO fetal fibroblasts.

Background and Aims: Altered glycosylation of the mucosal barrier has been proposed as a primary defect in the pathogenesis of IBD. Glycosylation defects however may also have a profound influence on immune function. Mice transgenic for human alpha1,2-fucosyl-transferase (hFUT1) have widespread disturbances in cell surface glycosylation and spontaneously develop colitis. The aims of this study were to characterize colitis in hFUT1 mice and to determine whether glycosylation-induced changes of the mucosal barrier or the immune system were critical for its pathogenesis., Methods: The pathologic features of hFUT1 transgenic mice were characterized. The mucosal barrier was assessed by lectin binding and permeability studies. T-cells and the thymus were assessed by FACS analysis and histology. To isolate the hFUT1 mucosal barrier from the hFUT1 immune system, bone marrow chimeras were generated., Results: Seventy percent of hFUT1 mice raised in SPF conditions developed histologic evidence of colitis. The mucosal barrier demonstrated altered glycosylation but intestinal permeability was preserved. HFUT1 mice were profoundly lymphopenic, with aberrant T-cell markers and thymic medullary hypoplasia. Reconstitution with wild type bone marrow restored thymic morphology and prevented colitis in hFUT1 mice., Conclusion: Altered glycosylation in hFUT1 mice has a profound influence on T-cell development and this defect, rather than a mucosal barrier defect, is crucial for the development of colitis., (Copyright 2004 Lippincott Williams & Wilkins)