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e12513Background: Eflapegrastim is a novel investigational biologic comprised of recombinant human G-CSF covalently linked to the human immunoglobulin G4FC fragment using proprietary LAPSCOVERY™ te...

TPS9106Background: Poziotinib is a novel, oral, quinazoline-based pan-HER inhibitor that irreversibly blocks signaling through the EGFR family of tyrosine-kinase receptors, including human epiderma...

Inflammation is a key pathological process in the progression of atherosclerosis and type 2 diabetes. 12/15-lipoxygenase (12-LO), an enzyme involved in fatty acid metabolism, may contribute to inflammatory damage triggered by stressors such as obesity and insulin resistance. We hypothesized that mice lacking 12-LO are protected against inflammatory-mediated damage associated with a “western” diet. To test this hypothesis, age-matched male 12-LO knockout (12-LOKO) and wild-type C57BL/6 (B6) mice were fed either a standard chow or western diet and assessed for several inflammatory markers. Western-fed B6 mice showed expected reductions in glucose and insulin tolerance compared with chow-fed mice. In contrast, western-fed 12-LOKO mice maintained glucose and insulin tolerance similar to chow-fed mice. Circulating proinflammatory cytokines, tumor necrosis factor-α and interleukin-6, were increased in western B6 mice but not 12-LOKO mice, whereas the reported protective adipokine, adiponectin, was decreased only in western B6 mice. 12-LO activity was significantly elevated by western diet in islets from B6 mice. Islets from 12-LOKO mice did not show western-diet-induced islet hyperplasia or increases in caspase-3 apoptotic staining observed in western-fed B6 mice. Islets from 12-LOKO mice were also protected from reduced glucose-stimulated insulin secretion observed in islets from western-fed B6 mice. In visceral fat, macrophage numbers and monocyte chemoattractant protein-1 expression were elevated in western B6 mice but not 12-LOKO mice. These data suggest that 12-LO activation plays a role in western-diet-induced damage in visceral fat and islets. Inhibiting 12-LO may provide a new therapeutic approach to prevent inflammation-mediated metabolic consequences of excess fat intake.

Protection of transplanted pancreatic islet grafts in recipients with autoimmune diabetes depends on the suppression of autoimmune recurrence and allogeneic rejection. The aim of this study was to investigate the efficiency of viral IL-10 gene delivery in the prevention of autoimmune recurrence following islet transplantation. We evaluated the effectiveness of a systemically delivered adeno-associated viral vector (AAV vIL-10) carrying viral IL-10 in protecting islet engraftment. We observed significant prolongation of graft survival after treatment with AAV vIL-10 when using islets from donors lacking autoimmunity. We found that the mechanism of vIL-10-mediated protection was associated with suppression of T cell activation and that donor immune cells that were simultaneously transferred with the islet grafts could induce autoimmune recurrence. AAV vIL-10 gene transfer suppressed previously activated T cells and protected grafted islets from autoimmune-mediated destruction. We conclude that vIL-10 can regulate autoimmune activity and that transfer of its gene may have potential for therapeutic islet transplantation.

Signal transducers and activators of transcription (STAT) proteins are activated in response to many cytokines, growth factors and hormones. STAT4 mediates IL-12 signaling and regulates T helper 1 (Th1) cell differentiation. Both IL-12 and Th1 cell activation participate in the development of autoimmune diabetes. In this study, we investigated the role of STAT4 in autoimmune diabetes. We crossbred Stat4 deficient (Stat4-/-) mice with nonobese diabetic (NOD) mice to generate the Stat4-/- NOD model. In Stat4-/- NOD mice, serum levels of both IFN-gamma and IL-2 were significantly reduced as compared to the controls. Insulin secretion in pancreatic islets was preserved in Stat4-/- NOD mice. Significantly, disruption of Stat4 activation completely prevented the development of spontaneous diabetes in NOD mice. This study reveals the important role of STAT4 in autoimmune diabetes pathogenesis.

BACKGROUND Pancreatic islet transplantation has become a promising treatment for type 1 diabetes. However, autoimmune reactivity destroys engrafted islets in type 1 diabetic recipients. The authors' previous studies demonstrated that a novel anti-inflammatory agent, lisofylline (LSF), suppressed autoimmune reactivity and protected nonobese diabetic (NOD) mice from diabetes. In this study, the authors investigated the potential of LSF in preventing autoimmune diabetes recurrence after islet transplantation. METHODS Spontaneously diabetic NOD mice received NOD severe combined immunodeficiency islet transplants and were treated with daily LSF injections at 50 mg/kg for 3 weeks. Blood glucose levels were monitored. Serum cytokine levels were measured at 1 and 3 weeks after engraftment. Nephrectomy of the islet-implanted kidney was performed in LSF-treated recipients. Histology of islet grafts was assessed at the end of the study. The effect of LSF on beta-cell function was studied in vitro. RESULTS Without immunosuppressants and insulin, the LSF-treated recipient mice maintained euglycemia significantly longer than the saline-treated recipients (mean, >65 days in the LSF-treated group vs. 6 days in saline controls; P=0.0004). Serum levels of interferon-gamma were markedly reduced in LSF-treated recipients at 1 and 3 weeks posttransplant. Diabetes recurred in the LSF-treated recipients after removing the islet-implanted kidneys. Immunohistochemistry showed retention of insulin-positive cells in the grafts of the LSF-treated recipients. LSF preserved beta-cell insulin secretory function in the presence of inflammatory cytokines in vitro. CONCLUSIONS This study demonstrates that autoimmune diabetes recurrence after islet transplantation could be prevented by treatment with LSF. LSF and its analogues may have the potential to prevent islet autoimmune destruction in clinical transplantation.

Background— Hyperglycemia (HG) and hyperinsulinemia (HI) may be factors enhancing the atherosclerotic complications of diabetes. We hypothesized that specific feeding of C57BL/6 apolipoprotein (apo) E −/− mice would alter their metabolic profiles and result in different degrees of neointima (NI) formation. We additionally hypothesized that an insulin-sensitizing agent (rosiglitazone) would prevent the development of type 2 diabetes and reduce neointima formation after carotid wire injury measured at 28 days. Methods and Results— Fasting glucose and insulin levels were elevated in the Western diet (WD) group, with a trend toward higher insulin levels and euglycemia in the fructose diet (FD)–fed mice. NI formation was exaggerated in the WD group compared with the FD or chow control groups. In the WD mice given rosiglitazone, glucose and insulin levels remained normal and NI formation was significantly reduced, as was NI macrophage content. Conclusions— These findings demonstrate that apoE −/− mice fed a WD develop type 2 diabetes with an exaggerated NI response to injury. FD mice maintain euglycemia but develop insulin resistance, with an intermediate degree of NI growth compared with chow diet controls. Rosiglitazone prevents the development of hyperglycemia and hyperinsulinemia and normalizes the insulin release profile in the apoE −/− , WD-fed mouse and significantly reduces NI formation by 65% after carotid wire injury while reducing macrophage infiltration. These data support the hypothesis that type 2 diabetes in the setting of elevated cholesterol accelerates the response to vascular injury and suggest that agents that improve insulin sensitivity may have therapeutic value in reducing restenosis in type 2 diabetes.

FTY720 is a novel immune regulatory drug derived from the fungal sphingosine analog ISP-1 (myriocin). FTY720 causes a redistribution of lymphocytes from circulation to secondary lymphoid tissues. Type 1 diabetes is an autoimmune disorder caused by cellular-mediated destruction of insulin-producing pancreatic β cells in the islets of Langerhans. Indeed, local infiltration of islets by mononuclear cells is the hallmark of Type 1 diabetes. Based on both FTY720’s action and the involvement of cellular infiltration in the disease progression, we tested FTY720 for its ability to prevent autoimmune diabetes in diabetes-prone, nonobese diabetic (NOD) mice. We found that treatment with FTY720 completely prevented NOD mice from developing autoimmune diabetes. The FTY720-treated animals showed both reduced numbers of circulating lymphocytes and sharply diminished cellular infiltration of pancreatic islets. These results suggest that FTY720 may be effective in prevention of autoimmune diabetes or in slowing its progression.

Th1 cell activation and cytokine production shift the balance between Th1 and Th2, favoring the up-regulation of proinflammatory activity that leads to destruction of insulin-producing pancreatic β cells in type 1 diabetes. Th2-type cytokines, such as IL-10, have immune regulatory function. Administration of IL-10, or IL-10 gene transfer, prevents autoimmune diabetes in nonobese diabetic (NOD) mice. However, constant administration of purified rIL-10 is not practical for long-term therapy to prevent diabetes. In this study, we transferred the BCRF-1 gene, an open reading frame in the Epstein-Barr viral genome with remarkable homology to mouse IL-10 (viral IL-10 or vIL-10), by an adeno-associated viral (AAV) vector to NOD mice to attain sustained vIL-10 gene expression. Like endogenous mouse IL-10, vIL-10 has potent immunoregulatory and immunosuppressive functions, but can be specifically distinguished from endogenous mouse IL-10 for monitoring of the transgene expression. A single systemic administration of AAV vIL-10 significantly reduced insulitis and prevented diabetes development in NOD mice. This protective effect correlated with sustained transgene expression and protein production. Moreover, splenocytes from the treated mice blocked diabetes transfer to NOD recipients, suggesting that vIL-10 induces an active suppression of autoimmunity. This study provides evidence to support the possibility of using vIL-10 gene therapy to prevent type 1 diabetes.

Background Systemic administration of soluble recombinant fusion protein of cytotoxic T lymphocyte antigen 4 (CTLA4Ig) induces blockade of the CD28/B7 costimulatory pathway and promotes survival of allogeneic and xenogeneic grafts. We tested the efficacy of local expression of CTLA4Ig gene in the myocardium, induced by transduction with a recombinant adenovirus encoding the CTLA4Ig gene, on the survival of rat cardiac allografts. Methods. The donor hearts were perfused ex vivo with recombinant adenovirus encoding CTLA4Ig cDNA (AdCTLA4Ig) via intra-aorta coronary artery before transplantation. The distribution and duration of CTLA4Ig transgene expression in the myocardium was assessed by reverse transcriptase polymerase chain reaction (RT-PCR) or in situ RT-PCR after transplantation. Results. In situ RT-PCR demonstrated abundant expression of CTLA4Ig transgene in the endo-myocardium of AdCTLA4Ig-perfused cardiac grafts. Lewis and Brown Norway cardiac allografts transduced with AdCTLA4Ig survived indefinitely in nonimmunosuppressed Wistar Furth recipients. However, donor-strain skin grafts were rejected by long-term recipients of cardiac allografts, which also triggered the rejection of the primary heart grafts. Conclusions. A single ex vivo intra-aortic infusion of recombinant adenovirus encoding the CTLA4Ig gene induced efficient transduction of the endo-myocardium and promoted the permanent survival of cardiac allografts in nonimmunosuppressed hosts. Despite the beneficial effect of local immunosuppression on cardiac allograft survival, the strategy failed to promote a state of donor-specific peripheral tolerance.

Background. One of the best-defined mechanisms for the induction of apoptosis involves signaling via the cell surface molecule Fas, after binding of Fas ligand. Expression of Fas ligand is tightly regulated, being expressed primarily by T cells after activation, where it serves as a self-regulatory mechanism for immune responses. Fas ligand has also been found to be expressed constitutively at sites of immune privilege such as the testes and the anterior chamber of the eye. Recently, co-transplantation of Fas ligand-transfected myoblasts in association with islet cell allografts was shown to prolong islet allograft survival but only rarely led to indefinite graft survival. Graft rejection was associated with loss of Fas ligand on the myoblasts, suggesting that direct expression of the transgene on the islets might be more effective. Methods. A replication-defective adenoviral construct containing murine Fas ligand (Ad/MFL) was prepared by homologous recombination. NIH 3T3 cells, rodent splenocytes, and murine islets were infected with Ad/MFL and examined in vitro for functional murine Fas ligand expression. Survival of Ad/MFL-infected islets was subsequently evaluated in vivo in both syngeneic and allogeneic islet transplantation models. Results. Cell lines and islet allografts transfected with Ad/MFL expressed a functional Fas ligand, capable of inducing apoptosis (confirmed by three distinct assays for DNA fragmentation) in Fas + targets, but not in Fas - controls. Furthermore, Ad/MFL was able to modify allogeneic immune responses in vitro, as addition of this virus, but not a control adenovirus, significantly reduced proliferation in a mixed lymphocyte reaction. Surprisingly, however, transplantation of islet allografts transfected with Ad/MFL resulted in long-term allograft survival in only 1 of 30 recipients. Moreover, adenoviral-mediated Fas ligand gene transfer was complicated by transient, dose-dependent islet dysfunction, perhaps contributing to the lack of long-term engraftment. Conclusion. These data suggest that adenoviral-mediated Fas ligand expression may impair normal islet function in vivo, and indicate that alternative strategies for Fas ligand transgene delivery may be required in this setting.

Autoimmune-mediated cytotoxicity may cause pancreatic islet transplant failure, leading to recurrent diabetes. Protection of islet grafts depends on immunosuppressive control, which may also prevent autoimmune recurrence of diabetes. In this study, we compared the survival of syngeneic islet transplants using different strains of donor mice. We observed extended functional survival in the islet grafts from donors lacking the genetic background and potential of autoimmunity. Without immunosuppression, the islet grafts of NOR and immune-deficient NOD. Scid donors functioned up to 3 weeks in syngeneic islet transplants compared to 3-day survivals with the grafts from NOD donors. T-cell proliferation and activation markers, CD44 and CD69, were upregulated in NOD donors, suggesting that T-cell activation had occurred prior to pancreas procurement. Systemic delivery of a recombinant adenoassociated viral vector (AAV) encoding the viral (vIL-10) IL-10 gene (AAV vIL-10) in NOD recipients protected syngeneic islets from autoimmune destruction. Alternatively, pretreatment of NOD donor mice with AAV vIL-10 prolonged islet graft survival in untreated NOD recipients. Both studies indicate the effectiveness of vIL-10 gene therapy in autoimmune regulation. These results suggest that a donor factor may exist in autoimmune-prone donors. Therefore, autoimmune recurrence of diabetes may result from donor immune cells transferred during islet transplantation. The AAV vIL-10 gene therapy suppressed previously activated donor T cells and protected the grafted islets from autoimmune-mediated destruction.

TPS3104 Background: hTERT, the human catalytic reverse transcriptase subunit of telomerase, is highly expressed in breast, lung, and pancreatic cancers. Peptides derived from hTERT can be recognize...

Type 1 diabetes mellitus (T1DM) is an autoimmune disease leading to near complete pancreatic beta-cell destruction. New evidence suggests that beta-cell regeneration is possible, but ongoing autoimmune damage prevents restoration of beta-cell mass. We tested the hypothesis that simultaneously blocking autoimmune cytokine damage and supplying a growth-promoting stimulus for beta-cells would provide a novel approach to reverse T1DM. Therefore, in this study we combined lisofylline to suppress autoimmunity and exendin-4 to enhance beta-cell proliferation for treating autoimmune-mediated diabetes in the non-obese diabetic (NOD) mouse model. We found that this combined therapy effectively reversed new-onset diabetes within a week of therapy, and even maintained euglycemia up to 145 days after treatment withdrawal. The therapeutic effect of this regimen was associated with improved beta-cell metabolism and insulin secretion, while reducing beta-cell apoptosis. It is possible that such combined therapy could become a new strategy to defeat T1DM in humans.

The pathogenesis of pancreatic beta-cell death in diabetes mellitus is still under investigation. Inflammation is likely to be one of the factors responsible for beta-cell death during disease development. In this study, we have used a novel antiinflammatory compound, Lisofylline (LSF), to investigate the role of inflammatory blockade in protecting human pancreatic islets. LSF is a small synthetic molecule that reduces inflammatory cytokine production and action, improves beta-cell mitochondrial metabolism, and regulates immune activities. The present study has demonstrated that the treatment of human islets with LSF not only allows the retention of glucose responsiveness and insulin secretion in the presence of multiple proinflammatory cytokines, but also enhances basal insulin secretion of beta cells in vitro. LSF also significantly reduces islet apoptosis, protects beta cells from proinflammatory cytokine damage, and maintains cellular viability. In a mouse transplantation model, insulin independence could be reached in diabetic recipient mice by implantation of 30% fewer islets when LSF was used in islet culture compared to the control group. These results demonstrate that LSF profoundly enhances beta-cell function, and suggest the potential of using inflammatory blockade, such as LSF, to improve beta-cell function for islet transplantation.

Pancreatic islet transplantation can replace insulin-secreting beta cells in patients with diabetes mellitus. However, current methodology for isolating islets from a pancreas only retrieves a portion of the total islets. Within these limited number of islets, nearly 50% of beta cells lose biological function before transplantation. Protecting and improving beta-cell viability and function was the goal of this study. Previously we observed that an anti-inflammatory compound, lisofylline (LSF), protects beta cells from cytotoxicity during diabetes development. In this study, we demonstrated that human islets treated in vitro with LSF retained beta-cell glucose responsiveness and insulin secretion in the presence of multiple proinflammatory cytokines. In addition, LSF treatment in vitro enhanced basal insulin production in beta cells, suggesting that LSF can directly improve beta-cell function. LSF reduced beta-cell apoptosis induced by proinflammatory cytokines by 50%. Importantly, 30% fewer LSF-treated islets were sufficient to achieve insulin independence in a murine islet transplantation model. These results demonstrate the ability of LSF-like compounds to protect and enhance beta-cell function, suggesting the potential of using LSF or its analogs in islet transplantation.

Pancreatic islet transplantation can replace functional insulin-secreting beta cells for patients with type 1 diabetes. More than 300 patients who have received islet transplantation have returned to a euglycemic condition without using insulin. Therefore, islet transplantation has gained public attention and interest. Unfortunately, shortages in organ donations, suboptional antirejection regimens, and difficulties in islet isolation limit clinical utilization of this therapy. Recently, successful islet transplantation has been reported using a centralized islet isolation facility. The advantage of this experience is that it avoids the high costs in building an isolation facility and maintaining an experienced technical team. However, a private airplane carrier was required for transporting islets back to the transplantation site in a remote hospital. The cost of this specialized transportation was still too high to be considered as a routine procedure. In this study, we report our experience using commercial carriers to deliver isolated human islets from an established isolation facility to a remote medical center.

Beta cell inflammation and cytokine-induced toxicity are central to autoimmune diabetes development. Lipid mediators generated upon lipoxygenase (LO) activation can participate in inflammatory pathways. 12LO-deficient mice are resistant to streptozotocin-induced diabetes. This study sought to characterise the cellular processes involving 12LO-activation lipid inflammatory mediator production in cytokine-treated pancreatic beta cells.Islets and beta cell lines were treated with a combination of IL-1beta, IFN-gamma and TNF-alpha, or the 12LO product 12(S)-hydroxyeicosatetraenoic acid (HETE). Insulin secretion was measured using an enzyme immunoassay, and cell viability was evaluated using an in situ terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling assay. 12LO activity was evaluated and 12LO protein levels were determined using immunoblotting with a selective leucocyte type 12LO antibody. Cellular localisation of 12LO was evaluated using immunocytochemistry.Basal expression of leucocyte type 12LO protein was found in human and mouse islets and in several rodent beta cell lines. In mouse beta-TC3 cells, and in human islets, cytokines induced release of 12-HETE within 30 min. Cytokine addition also induced a rapid translocation of 12LO protein from the cytosol to the nucleus of beta-TC3 cells as shown by subcellular fractionation and immunostaining. Cytokine-induced cell death and inhibition of insulin secretion were partially reversed by baicalein, a 12LO inhibitor. 12(S)-HETE inhibited beta-TC3 cell insulin release in a time- and concentration-dependent manner. Incubating beta-TC3 cells with 100 nmol/l of 12(S)-HETE resulted in a 57% reduction in basal insulin release (6 h), and a 17% increase in cell death (18 h) as compared with untreated cells. 12(S)-HETE activated the stress-activated protein kinase c-Jun N-terminal kinase and p38 within 15 min, as judged by increased kinase protein phosphorylation.The data suggest that inflammatory cytokines rapidly activate 12LO and show for the first time that cytokines induce 12LO translocation. The effects of 12-HETE on insulin secretion, cytotoxicity and kinase activation were similar to the effects seen with cytokines. The results provide mechanistic information of cytokine-induced toxic effects on pancreatic beta cells and support the hypothesis that blocking 12LO activation could provide a new therapeutic way to protect pancreatic beta cells from autoimmune injury.

Proinflammatory cytokines play an important role in the development of type 1 diabetes. Lisofylline (LSF) is a novel anti-inflammatory compound that specifically inhibits proinflammatory cytokine production and action.To investigate the effect of LSF on diabetes prevention.A mouse with diabetes induced by multiple low doses of streptozotocin (STZ) can be used as an animal model for type 1 diabetes. In this study, we used this method to induce diabetes in C57BL/6J mice. The daily LSF treatment started 5 days before STZ injections and lasted for 2 weeks. The incidence of diabetes was monitored. Insulin secretion was assessed in pancreatic islets isolated from experimental mice. Cytokine production was measured in mouse sera. Islet apoptosis was assessed quantitatively.In LSF-treated mice, there was a significant reduction of diabetes incidence (25% vs. 91.6%). This protection was associated with suppression of systemic levels of IFN-gamma and TNF-alpha, inhibition of macrophage infiltration in islets, restoration of islet insulin secretion, and reduction of beta-cell apoptosis.This study suggests that treatment with LSF suppresses proinflammatory cytokines and protects beta-cells from inflammation. LSF may be useful for prevention of type 1 diabetes and other disorders associated with excessive proinflammatory cytokines.

Proinflammatory cytokine-mediated pancreatic beta-cell dysfunction is a key pathological event in type I diabetes mellitus. Lisofylline (LSF), an anti-inflammatory agent, has been shown to protect pancreatic islets from IL-1 beta-induced inhibitory effects on insulin release. However, the mechanism of LSF action is not known. Increasing evidence suggests that the mitochondria play an important role in regulating the beta-cell insulin release capacity and the control of cellular viability. To examine the direct effects of LSF on beta-cells, insulin-secreting INS-1 cells were exposed to a combination of recombinant IL-1 beta, TNF alpha, and IFN gamma with or without LSF for 18 h. Basal and glucose-stimulated static insulin release were measured using RIA. INS-1 cell viability was determined using in situ terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling and LIVE/DEAD dual fluorescence labeling. To evaluate INS-1 mitochondrial function, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) metabolism, change in mitochondrial membrane potential, and intracellular ATP levels were assessed. Cytokine addition reduced basal (7.8 +/- 0.30 vs. 10.0 +/- 0.46 ng/ml.h; P < 0.005), glucose-stimulated insulin secretion (11.6 +/- 0.86 vs. 17.4 +/- 1.86 ng/ml.h; P < 0.005), and MTT metabolism in INS-1 cells. Over 40% of the cytokine-treated beta-cells exhibited nuclear DNA breakage, whereas the control cell death rate remained at 1-2%. Simultaneous application of LSF and cytokines to INS-1 cells restored insulin secretion, MTT metabolism, mitochondrial membrane potential, and cell viability to control levels. LSF increased beta-cell MTT metabolism as well as insulin release and glucose responsiveness. In summary, proinflammatory cytokines lead to a reduction of glucose-induced insulin secretion, mitochondrial activity, and viability in INS-1 cells. LSF at concentrations achievable in vivo protected beta-cells from the cytokine effects. The mechanism of LSF-induced protection may be by promoting mitochondrial metabolism.

5086 Background: Abiraterone acetate (AA) is a prodrug of abiraterone, which is a selective, irreversible CYP17 inhibitor of androgen biosynthesis and significantly reduces testosterone production ...

Type 1 diabetes is the result of a selective destruction of pancreatic islets by autoreactive T-cells. Therefore, in the context of islet or pancreas transplantation, newly transplanted beta-cells are threatened by both recurrent autoimmune and alloimmune responses in recipients with type 1 diabetes. In the present study, using spontaneously diabetic BB rats, we demonstrate that whereas isolated islets are susceptible to autoimmune recurrence and rejection, pancreaticoduodenal grafts are resistant to these biological processes. This resistance is mediated by lymphohematopoietic cells transplanted with the graft, since inactivation of these passenger cells by irradiation uniformly rendered the pancreaticoduodenal grafts susceptible to recurrent autoimmunity. We further studied the impact of local immunomodulation on autoimmune recurrence and rejection by ex vivo adenovirus-mediated CTLA4Ig gene transfer to pancreaticoduodenal grafts. Syngeneic DR-BB pancreaticoduodenal grafts transduced with AdmCTLA4Ig were rescued from recurrent autoimmunity. In fully histoincompatible LEW-->BB transplants, in which rejection and recurrence should be able to act synergistically, AdmCTLA4Ig transduced LEW-pancreaticoduodenal allografts enjoyed markedly prolonged survival in diabetic BB recipients. In situ reverse transcription-polymerase chain reaction revealed that transferred CTLA4Ig gene was strongly expressed in both endocrine and exocrine tissues on day 3. These results indicate the potential utility of local CD28-B7 costimulatory blockade for prevention of alloimmune and autoimmune destruction of pancreatic grafts in type 1 diabetic hosts.