As a service to our customers we are providing this early version of the manuscript. poor adaptive response that was diminished when compared with that to a GTKO/CD46 graft. Blockade of both pathways prevented an adaptive response. Conclusion Although expression of the mutant MHC CIITA-DN gene was associated with a reduced adaptive immune response when immunosuppressive therapy was inadequate, when blockade of both the CD40/CD154 and CD28/B7 pathways was present, the response even to a GTKO/CD46 graft was suppressed. This was confirmed after GTKO/CD46 heart transplantation in baboons. species, n=20; Division of Animal Resources, Oklahoma University Health Sciences Center, Oklahoma City, OK), 3C4 years-old, weighing 6C9kg and of known AB blood type, were recipients of pig artery patch (n=16) or heterotopic heart (n=4) grafts. Zolpidem GTKO/CD46/CIITA-DN, GTKO/CD46, or GTKO pigs of blood group O (nonA), weighing 30C80kg (Revivicor, Blacksburg, VA), generated by nuclear transfer/embryo transfer from altered fibroblasts from Large White/Landrace/Duroc cross-breed pigs [1,18,52], served as sources of carotid artery patches or hearts. Some pigs provided two or more patch grafts. All pigs were tested to confirm (i) absence of Gal expression and (ii) expression of CD46 and CIITA-DN in the vascular endothelium of the aorta (18,53). GTKO/CD46 pig cells have been demonstrated to provide considerable protection against the primate humoral Zolpidem immune response [53,54] and CIITA-DN pig cells have been shown to protect from the primate adaptive response (18). assays were carried out on cells from GTKO/CD46/CIITA-DN pigs to demonstrate the efficacy of the mutant human MHC class II transactivator gene. All animal care was in accordance with the formulated by the National Society for Medical Research and the prepared by the Institute of Laboratory Animal Resources and published by the National Institutes of Health (NIH publication No. 86-23, revised 1985). Protocols were approved by the University of Zolpidem Pittsburgh Institutional Animal Care and Use Committee. Surgical procedures Anesthesia in pigs and baboons, and intravascular catheter placements in baboons have been described previously [55], as has the surgical technique of pig artery patch transplantation in baboons [16]. A 21cm patch was sutured into the anterior wall of the abdominal aorta as an onlay graft. The ischemic period was 2C3h in all cases. The technique of heterotopic heart transplantation has also been described previously (9,13,14,55). Experimental groups (Table 1) Table 1 Details of Group 1 and 2 Experiments studies indicated that belatacept had a stronger suppressive effect on MLR (the inhibitory effect on baboon T cell proliferation induced by pig ECs) than anti-CD40mAb (Hara H, et al, manuscript in preparation), and so we did not put a priority on testing this latter agent study that exhibited that belatacept was a more powerful suppressive agent than anti-CD154mAb [66], which is clearly not the case However, in the present study, the anti-CD40mAb (2C10R4) Cish3 was prepared against rhesus monkeys rather than baboons, and this may be important. Furthermore, Mohiuddin et al have demonstrated prolonged graft survival of pig hearts in baboons receiving high doses of this agent in the absence of belatacept [67]; anti-CD40mAb alone at high dosage (50mg/kg) therefore appears to be sufficient. The T cell proliferative response, the IgM and IgG antibody responses, and the extent of cellular infiltration of the graft were all marginally greater when baboons received grafts from GTKO/CD46 pigs than from pigs additionally transgenic for CIITA-DN, but the heart transplant studies indicated that this advantage may not be clinically important in regard to the immediate T cell response. However, although we emphasize that we currently have no data to support such a conclusion, we tentatively suggest that, through reducing the effects of graft endothelial activation by inhibiting upregulation of SLA class II, CIITA-DN might show beneficial in inhibiting the development of graft vasculopathy (chronic rejection). We have not yet decided whether the pig endothelial cells of the graft are replaced to any extent by baboon endothelial cells. However, even if this is the case, the model is sufficient to stimulate an immune response. In our studies, no increase in SLA.
