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1.  Islet Transplantation Stabilizes Hemostatic Abnormalities and Cerebral Metabolism in Individuals With Type 1 Diabetes 
Diabetes Care  2013;37(1):267-276.
OBJECTIVE
Islets after kidney transplantation have been shown to positively affect the quality of life of individuals with type 1 diabetes (T1D) by reducing the burden of diabetes complications, but fewer data are available for islet transplantation alone (ITA). The aim of this study was to assess whether ITA has a positive impact on hemostatic and cerebral abnormalities in individuals with T1D.
RESEARCH DESIGN AND METHODS
Prothrombotic factors, platelet function/ultrastructure, and cerebral morphology, metabolism, and function have been investigated over a 15-month follow-up period using ELISA/electron microscopy and magnetic resonance imaging, nuclear magnetic resonance spectroscopy, and neuropsychological evaluation (Profile of Mood States test and paced auditory serial addition test) in 22 individuals with T1D who underwent ITA (n = 12) or remained on the waiting list (n = 10). Patients were homogeneous with regard to metabolic criteria, hemostatic parameters, and cerebral morphology/metabolism/function at the time of enrollment on the waiting list.
RESULTS
At the 15-month follow-up, the group undergoing ITA, but not individuals with T1D who remained on the waiting list, showed 1) improved glucose metabolism; 2) near-normal platelet activation and prothrombotic factor levels; 3) near-normal cerebral metabolism and function; and 4) a near-normal neuropsychological test.
CONCLUSIONS
ITA, despite immunosuppressive therapy, is associated with a near-normalization of hemostatic and cerebral abnormalities.
doi:10.2337/dc13-1663
PMCID: PMC3867995  PMID: 24026546
2.  Autologous Pancreatic Islet Transplantation in Human Bone Marrow 
Diabetes  2013;62(10):3523-3531.
The liver is the current site of choice for pancreatic islet transplantation, even though it is far from being ideal. We recently have shown in mice that the bone marrow (BM) may be a valid alternative to the liver, and here we report a pilot study to test feasibility and safety of BM as a site for islet transplantation in humans. Four patients who developed diabetes after total pancreatectomy were candidates for the autologous transplantation of pancreatic islet. Because the patients had contraindications for intraportal infusion, islets were infused in the BM. In all recipients, islets engrafted successfully as shown by measurable posttransplantation C-peptide levels and histopathological evidence of insulin-producing cells or molecular markers of endocrine tissue in BM biopsy samples analyzed during follow-up. Thus far, we have recorded no adverse events related to the infusion procedure or the presence of islets in the BM. Islet function was sustained for the maximum follow-up of 944 days. The encouraging results of this pilot study provide new perspectives in identifying alternative sites for islet infusion in patients with type 1 diabetes. Moreover, this is the first unequivocal example of successful engraftment of endocrine tissue in the BM in humans.
doi:10.2337/db13-0465
PMCID: PMC3781459  PMID: 23733196
3.  Effect of the Purinergic Inhibitor Oxidized ATP in a Model of Islet Allograft Rejection 
Diabetes  2013;62(5):1665-1675.
The lymphocytic ionotropic purinergic P2X receptors (P2X1R-P2X7R, or P2XRs) sense ATP released during cell damage-activation, thus regulating T-cell activation. We aim to define the role of P2XRs during islet allograft rejection and to establish a novel anti-P2XRs strategy to achieve long-term islet allograft function. Our data demonstrate that P2X1R and P2X7R are induced in islet allograft-infiltrating cells, that only P2X7R is increasingly expressed during alloimmune response, and that P2X1R is augmented in both allogeneic and syngeneic transplantation. In vivo short-term P2X7R targeting (using periodate-oxidized ATP [oATP]) delays islet allograft rejection, reduces the frequency of Th1/Th17 cells, and induces hyporesponsiveness toward donor antigens. oATP-treated mice displayed preserved islet grafts with reduced Th1 transcripts. P2X7R targeting and rapamycin synergized in inducing long-term islet function in 80% of transplanted mice and resulted in reshaping of the recipient immune system. In vitro P2X7R targeting using oATP reduced T-cell activation and diminished Th1/Th17 cytokine production. Peripheral blood mononuclear cells obtained from long-term islet-transplanted patients showed an increased percentage of P2X7R+CD4+ T cells compared with controls. The beneficial effects of oATP treatment revealed a role for the purinergic system in islet allograft rejection, and the targeting of P2X7R is a novel strategy to induce long-term islet allograft function.
doi:10.2337/db12-0242
PMCID: PMC3636636  PMID: 23315496
4.  Alloantibody and Autoantibody Monitoring Predicts Islet Transplantation Outcome in Human Type 1 Diabetes 
Diabetes  2013;62(5):1656-1664.
Long-term clinical outcome of islet transplantation is hampered by the rejection and recurrence of autoimmunity. Accurate monitoring may allow for early detection and treatment of these potentially compromising immune events. Islet transplant outcome was analyzed in 59 consecutive pancreatic islet recipients in whom baseline and de novo posttransplant autoantibodies (GAD antibody, insulinoma-associated protein 2 antigen, zinc transporter type 8 antigen) and donor-specific alloantibodies (DSA) were quantified. Thirty-nine recipients (66%) showed DSA or autoantibody increases (de novo expression or titer increase) after islet transplantation. Recipients who had a posttransplant antibody increase showed similar initial performance but significantly lower graft survival than patients without an increase (islet autoantibodies P < 0.001, DSA P < 0.001). Posttransplant DSA or autoantibody increases were associated with HLA-DR mismatches (P = 0.008), induction with antithymocyte globulin (P = 0.0001), and pretransplant panel reactive alloantibody >15% in either class I or class II (P = 0.024) as independent risk factors and with rapamycin as protective (P = 0.006) against antibody increases. DSA or autoantibody increases after islet transplantation are important prognostic markers, and their identification could potentially lead to improved islet cell transplant outcomes.
doi:10.2337/db12-1258
PMCID: PMC3636624  PMID: 23274902
5.  Improvement in Outcomes of Clinical Islet Transplantation: 1999–2010 
Diabetes Care  2012;35(7):1436-1445.
OBJECTIVE
To describe trends of primary efficacy and safety outcomes of islet transplantation in type 1 diabetes recipients with severe hypoglycemia from the Collaborative Islet Transplant Registry (CITR) from 1999 to 2010.
RESEARCH DESIGN AND METHODS
A total of 677 islet transplant-alone or islet-after-kidney recipients with type 1 diabetes in the CITR were analyzed for five primary efficacy outcomes and overall safety to identify any differences by early (1999–2002), mid (2003–2006), or recent (2007–2010) transplant era based on annual follow-up to 5 years.
RESULTS
Insulin independence at 3 years after transplant improved from 27% in the early era (1999–2002, n = 214) to 37% in the mid (2003–2006, n = 255) and to 44% in the most recent era (2007–2010, n = 208; P = 0.006 for years-by-era; P = 0.01 for era alone). C-peptide ≥0.3 ng/mL, indicative of islet graft function, was retained longer in the most recent era (P < 0.001). Reduction of HbA1c and resolution of severe hypoglycemia exhibited enduring long-term effects. Fasting blood glucose stabilization also showed improvements in the most recent era. There were also modest reductions in the occurrence of adverse events. The islet reinfusion rate was lower: 48% by 1 year in 2007–2010 vs. 60–65% in 1999–2006 (P < 0.01). Recipients that ever achieved insulin-independence experienced longer duration of islet graft function (P < 0.001).
CONCLUSIONS
The CITR shows improvement in primary efficacy and safety outcomes of islet transplantation in recipients who received transplants in 2007–2010 compared with those in 1999–2006, with fewer islet infusions and adverse events per recipient.
doi:10.2337/dc12-0063
PMCID: PMC3379615  PMID: 22723582
6.  Endothelial Progenitor Cells Carrying Monocyte Markers Are Selectively Abnormal in Type 1 Diabetic Patients With Early Retinopathy 
Diabetes  2012;61(4):908-914.
Endothelial progenitor cells (EPCs) enter the systemic circulation in response to cues related to vascular damage and need for neovascularization. Thus, EPCs could become readily accessible informers of vascular status and enable the survey of vascular pathologies during preclinical stages. To identify EPC changes with biomarker potential, we investigated whether discrete EPC abnormalities were associated with early nonproliferative diabetic retinopathy (NPDR). Two EPC subtypes with different functions have been characterized to date—one solely committed to the endothelial lineage and the other carrying both endothelial and monocytic markers. We found that only the latter, colony-forming units (CFU)-Hill cells, manifested abnormalities in type 1 diabetic patients with NPDR compared with control subjects. The abnormalities consisted in an increased number of colonies formed in vitro and downregulation of the molecules that facilitate homing at sites of vascular injury. The abnormalities were absent in type 1 diabetic patients free of retinopathy and other complications, despite long diabetes duration, but were detected in some of the patients without clinical retinopathy after short diabetes duration. CFU-Hill cells are potential informers of diabetic microangiopathy but may be preempted from carrying out reparative functions if the molecular abnormalities compromise interactions with the damaged vascular wall.
doi:10.2337/db11-1197
PMCID: PMC3314367  PMID: 22338095
7.  Near Normalization of Metabolic and Functional Features of the Central Nervous System in Type 1 Diabetic Patients With End-Stage Renal Disease After Kidney-Pancreas Transplantation 
Diabetes Care  2012;35(2):367-374.
OBJECTIVE
The pathogenesis of brain disorders in type 1 diabetes (T1D) is multifactorial and involves the adverse effects of chronic hyperglycemia and of recurrent hypoglycemia. Kidney-pancreas (KP), but not kidney alone (KD), transplantation is associated with sustained normoglycemia, improvement in quality of life, and reduction of morbidity/mortality in diabetic patients with end-stage renal disease (ESRD).
RESEARCH DESIGN AND METHODS
The aim of our study was to evaluate with magnetic resonance imaging and nuclear magnetic resonance spectroscopy (1H MRS) the cerebral morphology and metabolism of 15 ESRD plus T1D patients, 23 patients with ESRD plus T1D after KD (n = 9) and KP (n = 14) transplantation, and 8 age-matched control subjects.
RESULTS
Magnetic resonance imaging showed a higher prevalence of cerebrovascular disease in ESRD plus T1D patients (53% [95% CI 36–69]) compared with healthy subjects (25% [3–6], P = 0.04). Brain 1H MRS showed lower levels of N-acetyl aspartate (NAA)-to-choline ratio in ESRD plus T1D, KD, and KP patients compared with control subjects (control subjects vs. all, P < 0.05) and of NAA-to-creatine ratio in ESRD plus T1D compared with KP and control subjects (ESRD plus T1D vs. control and KP subjects, P ≤ 0.01). The evaluation of the most common scores of psychological and neuropsychological function showed a generally better intellectual profile in control and KP subjects compared with ESRD plus T1D and KD patients.
CONCLUSIONS
Diabetes and ESRD are associated with a precocious form of brain impairment, chronic cerebrovascular disease, and cognitive decline. In KP-transplanted patients, most of these features appeared to be near normalized after a 5-year follow-up period of sustained normoglycemia.
doi:10.2337/dc11-1697
PMCID: PMC3263904  PMID: 22190674
8.  Inotuzumab Ozogamicin Murine Analog–Mediated B-Cell Depletion Reduces Anti-islet Allo- and Autoimmune Responses 
Diabetes  2011;61(1):155-165.
B cells participate in the priming of the allo- and autoimmune responses, and their depletion can thus be advantageous for islet transplantation. Herein, we provide an extensive study of the effect of B-cell depletion in murine models of islet transplantation. Islet transplantation was performed in hyperglycemic B-cell–deficient(μMT) mice, in a purely alloimmune setting (BALB/c into hyperglycemic C57BL/6), in a purely autoimmune setting (NOD.SCID into hyperglycemic NOD), and in a mixed allo-/autoimmune setting (BALB/c into hyperglycemic NOD). Inotuzumab ozogamicin murine analog (anti-CD22 monoclonal antibody conjugated with calicheamicin [anti-CD22/cal]) efficiently depleted B cells in all three models of islet transplantation examined. Islet graft survival was significantly prolonged in B-cell–depleted mice compared with control groups in transplants of islets from BALB/c into C57BL/6 (mean survival time [MST]: 16.5 vs. 12.0 days; P = 0.004), from NOD.SCID into NOD (MST: 23.5 vs. 14.0 days; P = 0.03), and from BALB/c into NOD (MST: 12.0 vs. 5.5 days; P = 0.003). In the BALB/c into B-cell–deficient mice model, islet survival was prolonged as well (MST: μMT = 32.5 vs. WT = 14 days; P = 0.002). Pathology revealed reduced CD3+ cell islet infiltration and confirmed the absence of B cells in treated mice. Mechanistically, effector T cells were reduced in number, concomitant with a peripheral Th2 profile skewing and ex vivo recipient hyporesponsiveness toward donor-derived antigen as well as islet autoantigens. Finally, an anti-CD22/cal and CTLA4-Ig–based combination therapy displayed remarkable prolongation of graft survival in the stringent model of islet transplantation (BALB/c into NOD). Anti-CD22/cal–mediated B-cell depletion promotes the reduction of the anti-islet immune response in various models of islet transplantation.
doi:10.2337/db11-0684
PMCID: PMC3237644  PMID: 22076927
9.  IL-21 Is an Antitolerogenic Cytokine of the Late-Phase Alloimmune Response 
Diabetes  2011;60(12):3223-3234.
OBJECTIVE
Interleukin-21 (IL-21) is a proinflammatory cytokine that has been shown to affect Treg/Teff balance. However, the mechanism by which IL-21 orchestrates alloimmune response and interplays with Tregs is still unclear.
RESEARCH DESIGN AND METHODS
The interplay between IL-21/IL-21R signaling, FoxP3 expression, and Treg survival and function was evaluated in vitro in immunologically relevant assays and in vivo in allogenic and autoimmune models of islet transplantation.
RESULTS
IL-21R expression decreases on T cells and B cells in vitro and increases in the graft in vivo, while IL-21 levels increase in vitro and in vivo during anti-CD3/anti-CD28 stimulation/allostimulation in the late phase of the alloimmune response. In vitro, IL-21/IL-21R signaling (by using rmIL-21 or genetically modified CD4+ T cells [IL-21 pOrf plasmid–treated or hIL-21-Tg mice]) enhances the T-cell response during anti-CD3/anti-CD28 stimulation/allostimulation, prevents Treg generation, inhibits Treg function, induces Treg apoptosis, and reduces FoxP3 and FoxP3-dependent gene transcripts without affecting FoxP3 methylation status. In vivo targeting of IL-21/IL-21R expands intragraft and peripheral Tregs, promotes Treg neogenesis, and regulates the antidonor immune response, whereas IL-21/IL-21R signaling in Doxa-inducible ROSA-rtTA-IL-21-Tg mice expands Teffs and FoxP3− cells. Treatment with a combination of mIL-21R.Fc and CTLA4-Ig (an inhibitor of the early alloimmune response) leads to robust graft tolerance in a purely alloimmune setting and prolonged islet graft survival in NOD mice.
CONCLUSIONS
IL-21 interferes with different checkpoints of the FoxP3 Treg chain in the late phase of alloimmune response and, thus, acts as an antitolerogenic cytokine. Blockade of the IL-21/IL-21R pathway could be a precondition for tolerogenic protocols in transplantation.
doi:10.2337/db11-0880
PMCID: PMC3219943  PMID: 22013017
10.  Expansion of Th17 Cells and Functional Defects in T Regulatory Cells Are Key Features of the Pancreatic Lymph Nodes in Patients With Type 1 Diabetes 
Diabetes  2011;60(11):2903-2913.
OBJECTIVE
Autoimmune diseases, including type 1 diabetes, are thought to have a Th17-cell bias and/or a T-regulatory cell (Treg) defect. Understanding whether this is a hallmark of patients with type 1 diabetes is a crucial question that is still unsolved, largely due to the difficulties of accessing tissues targeted by the disease.
RESEARCH DESIGN AND METHODS
We phenotypically and functionally characterized Th17 cells and Tregs residing in the pancreatic-draining lymph nodes (PLNs) of 19 patients with type 1 diabetes and 63 nondiabetic donors and those circulating in the peripheral blood of 14 type 1 diabetic patients and 11 healthy subjects.
RESULTS
We found upregulation of Th17 immunity and functional defects in CD4+CD25bright Tregs in the PLNs of type 1 diabetic subjects but not in their peripheral blood. In addition, the proinsulin-specific Treg-mediated control was altered in the PLNs of diabetic patients. The dysfunctional Tregs isolated from diabetic subjects did not contain contaminant effector T cells and were all epigenetically imprinted to be suppressive, as defined by analysis of the Treg-specific demethylated region within the forkhead box P3 (FOXP3) locus.
CONCLUSIONS
These data provide evidence for an unbalanced immune status in the PLNs of type 1 diabetic subjects, and treatments restoring the immune homeostasis in the target organ of these patients represent a potential therapeutic strategy.
doi:10.2337/db11-0090
PMCID: PMC3198077  PMID: 21896932
11.  CXCR1/2 inhibition enhances pancreatic islet survival after transplantation 
The Journal of Clinical Investigation  2012;122(10):3647-3651.
Although long considered a promising treatment option for type 1 diabetes, pancreatic islet cell transformation has been hindered by immune system rejection of engrafted tissue. The identification of pathways that regulate post-transplant detrimental inflammatory events would improve management and outcome of transplanted patients. Here, we found that CXCR1/2 chemokine receptors and their ligands are crucial negative determinants for islet survival after transplantation. Pancreatic islets released abundant CXCR1/2 ligands (CXCL1 and CXCL8). Accordingly, intrahepatic CXCL1 and circulating CXCL1 and CXCL8 were strongly induced shortly after islet infusion. Genetic and pharmacological blockade of the CXCL1-CXCR1/2 axis in mice improved intrahepatic islet engraftment and reduced intrahepatic recruitment of polymorphonuclear leukocytes and NKT cells after islet infusion. In humans, the CXCR1/2 allosteric inhibitor reparixin improved outcome in a phase 2 randomized, open-label pilot study with a single infusion of allogeneic islets. These findings indicate that the CXCR1/2-mediated pathway is a regulator of islet damage and should be a target for intervention to improve the efficacy of transplantation.
doi:10.1172/JCI63089
PMCID: PMC3461913  PMID: 22996693
12.  Strategies to Reverse Endothelial Progenitor Cell Dysfunction in Diabetes 
Experimental Diabetes Research  2012;2012:471823.
Bone-marrow-derived cells-mediated postnatal vasculogenesis has been reported as the main responsible for the regulation of vascular homeostasis in adults. Since their discovery, endothelial progenitor cells have been depicted as mediators of postnatal vasculogenesis for their peculiar phenotype (partially staminal and partially endothelial), their ability to differentiate in endothelial cell line and to be incorporated into the vessels wall during ischemia/damage. Diabetes mellitus, a condition characterized by cardiovascular disease, nephropathy, and micro- and macroangiopathy, showed a dysfunction of endothelial progenitor cells. Herein, we review the mechanisms involved in diabetes-related dysfunction of endothelial progenitor cells, highlighting how hyperglycemia affects the different steps of endothelial progenitor cells lifetime (i.e., bone marrow mobilization, trafficking into the bloodstream, differentiation in endothelial cells, and homing in damaged tissues/organs). Finally, we review preclinical and clinical strategies that aim to revert diabetes-induced dysfunction of endothelial progenitor cells as a means of finding new strategies to prevent diabetic complications.
doi:10.1155/2012/471823
PMCID: PMC3296202  PMID: 22474422
13.  A map of open chromatin in human pancreatic islets 
Nature genetics  2010;42(3):255-259.
Tissue-specific transcriptional regulation is central to human disease1. To identify regulatory DNA active in human pancreatic islets, we profiled chromatin by FAIRE (Formaldehyde-Assisted Isolation of Regulatory Elements)2–4 coupled with high-throughput sequencing. We identified ~80,000 open chromatin sites. Comparison of islet FAIRE-seq to five non-islet cell lines revealed ~3,300 physically linked clusters of islet-selective open chromatin sites, which typically encompassed single genes exhibiting islet-specific expression. We mapped sequence variants to open chromatin sites and found that rs7903146, a TCF7L2 intronic variant strongly associated with type 2 diabetes (T2D)5, is located in islet-selective open chromatin. We show that rs7903146 heterozygotes exhibit allelic imbalance in islet FAIRE signal, and that the variant alters enhancer activity, indicating that genetic variation at this locus acts in cis with local chromatin and regulatory changes. These findings illuminate the tissue-specific organization of cis-regulatory elements, and show that FAIRE-seq can guide identification of regulatory variants important for disease.
doi:10.1038/ng.530
PMCID: PMC2828505  PMID: 20118932
14.  Proteomics Reveals Novel Oxidative and Glycolytic Mechanisms in Type 1 Diabetic Patients' Skin Which Are Normalized by Kidney-Pancreas Transplantation 
PLoS ONE  2010;5(3):e9923.
Background
In type 1 diabetes (T1D) vascular complications such as accelerated atherosclerosis and diffused macro-/microangiopathy are linked to chronic hyperglycemia with a mechanism that is not yet well understood. End-stage renal disease (ESRD) worsens most diabetic complications, particularly, the risk of morbidity and mortality from cardiovascular disease is increased several fold.
Methods and Findings
We evaluated protein regulation and expression in skin biopsies obtained from T1D patients with and without ESRD, to identify pathways of persistent cellular changes linked to diabetic vascular disease. We therefore examined pathways that may be normalized by restoration of normoglycemia with kidney-pancreas (KP) transplantation. Using proteomic and ultrastructural approaches, multiple alterations in the expression of proteins involved in oxidative stress (catalase, superoxide dismutase 1, Hsp27, Hsp60, ATP synthase δ chain, and flavin reductase), aerobic and anaerobic glycolysis (ACBP, pyruvate kinase muscle isozyme, and phosphoglycerate kinase 1), and intracellular signaling (stratifin-14-3-3, S100-calcyclin, cathepsin, and PPI rotamase) as well as endothelial vascular abnormalities were identified in T1D and T1D+ESRD patients. These abnormalities were reversed after KP transplant. Increased plasma levels of malondialdehyde were observed in T1D and T1D+ESRD patients, confirming increased oxidative stress which was normalized after KP transplant.
Conclusions
Our data suggests persistent cellular changes of anti-oxidative machinery and of aerobic/anaerobic glycolysis are present in T1D and T1D+ESRD patients, and these abnormalities may play a key role in the pathogenesis of hyperglycemia-related vascular complications. Restoration of normoglycemia and removal of uremia with KP transplant can correct these abnormalities. Some of these identified pathways may become potential therapeutic targets for a new generation of drugs.
doi:10.1371/journal.pone.0009923
PMCID: PMC2848014  PMID: 20360867
15.  Rapamycin Monotherapy in Patients With Type 1 Diabetes Modifies CD4+CD25+FOXP3+ Regulatory T-Cells 
Diabetes  2008;57(9):2341-2347.
OBJECTIVE—Rapamycin is an immunosuppressive drug currently used to prevent graft rejection in humans, which is considered permissive for tolerance induction. Rapamycin allows expansion of both murine and human naturally occurring CD4+CD25+FOXP3+ T regulatory cells (nTregs), which are pivotal for the induction and maintenance of peripheral tolerance. Preclinical murine models have shown that rapamycin enhances nTreg proliferation and regulatory function also in vivo. Objective of this study was to assess whether rapamycin has in vivo effects on human nTregs.
RESEARCH DESIGN AND METHODS—nTreg numbers and function were examined in a unique set of patients with type 1 diabetes who underwent rapamycin monotherapy before islet transplantation.
RESULTS—We found that rapamycin monotherapy did not alter the frequency and functional features, namely proliferation and cytokine production, of circulating nTregs. However, nTregs isolated from type 1 diabetic patients under rapamycin treatment had an increased capability to suppress proliferation of CD4+CD25− effector T-cells compared with that before treatment.
CONCLUSIONS—These findings demonstrate that rapamycin directly affects human nTreg function in vivo, which consists of refitting their suppressive activity, whereas it does not directly change effector T-cell function.
doi:10.2337/db08-0138
PMCID: PMC2518485  PMID: 18559659
16.  Islet transplantation in patients with autoimmune diabetes induces homeostatic cytokines that expand autoreactive memory T cells 
The Journal of Clinical Investigation  2008;118(5):1806-1814.
Successful transplantation requires the prevention of allograft rejection and, in the case of transplantation to treat autoimmune disease, the suppression of autoimmune responses. The standard immunosuppressive treatment regimen given to patients with autoimmune type 1 diabetes who have received an islet transplant results in the loss of T cells. In many other situations, the immune system responds to T cell loss through cytokine-dependant homeostatic proliferation of any remaining T cells. Here we show that T cell loss after islet transplantation in patients with autoimmune type 1 diabetes was associated with both increased serum concentrations of IL-7 and IL-15 and in vivo proliferation of memory CD45RO+ T cells, highly enriched in autoreactive glutamic acid decarboxylase 65–specific T cell clones. Immunosuppression with FK506 and rapamycin after transplantation resulted in a chronic homeostatic expansion of T cells, which acquired effector function after immunosuppression was removed. In contrast, the cytostatic drug mycophenolate mofetil efficiently blocked homeostatic T cell expansion. We propose that the increased production of cytokines that induce homeostatic expansion could contribute to recurrent autoimmunity in transplanted patients with autoimmune disease and that therapy that prevents the expansion of autoreactive T cells will improve the outcome of islet transplantation.
doi:10.1172/JCI35197
PMCID: PMC2323193  PMID: 18431516

Results 1-16 (16)