Mechanisms of Immunomodulation and Cytoprotection Conferred to Pancreatic Islet by Human Amniotic Epithelial Cells

Inhibiting pro-inflammatory cytokine activity can reverse inflammation mediated dysfunction of islet grafts. Human amniotic epithelial cells (hAECs) possess regenerative, immunomodulatory and anti-inflammatory properties. We hypothesized that hAECs could protect islets from cellular damage induced by pro-inflammatory cytokines. To verify our hypothesis, hAEC monocultures, rat islets (RI), or RI-hAEC co-cultures where exposed to a pro-inflammatory cytokine cocktail (Interferon γ: IFN-γ, Tumor necrosis factor α: TNF-α and Interleukin-1β: IL-1β). The secretion of anti-inflammatory cytokines and gene expression changes in hAECs and viability and function of RI were evaluated. The expression of non-classical Major Histocompatibility Complex (MHC) class I molecules by hAECs cultured with various IFN-γ concentrations were assessed. Exposure to the pro-inflammatory cocktail significantly increased the secretion of the anti-inflammatory cytokines IL6, IL10 and G-CSF by hAECs, which was confirmed by upregulation of IL6, and IL10 gene expression. HLA-G, HLA-E and PDL-1 gene expression was also increased. This correlated with an upregulation of STAT1, STAT3 and NF-κB1gene expression levels. RI co-cultured with hAECs maintained normal function after cytokine exposure compared to RI cultured alone, and showed significantly lower apoptosis rate. Our results show that exposure to pro-inflammatory cytokines stimulates secretion of anti-inflammatory and immunomodulatory factors by hAECs through the JAK1/2 – STAT1/3 and the NF-κB1 pathways, which in turn protects islets against inflammation-induced damages. Integrating hAECs in islet transplants appears as a valuable strategy to achieve to inhibit inflammation mediated islet damage, prolong islet survival, improve their engraftment and achieve local immune protection allowing reducing systemic immunosuppressive regimens. Graphical Abstract This study focuses on the cytoprotective effect of isolated hAECs on islets exposed to pro-inflammatory cytokines in vitro. Exposure to pro-inflammatory cytokines stimulated secretion of anti-inflammatory and immunomodulatory factors by hAECs putatively through the JAK1/2 – STAT1/3 and the NF-κB1 pathways. This had protective effect on islets against inflammation-induced damages. Taken together our results indicate that incorporating hAECs in islet transplants could be a valuable strategy to inhibit inflammation mediated islet damage, prolong islet survival, improve their engraftment and achieve local immune protection allowing to reduce systemic immunosuppressive regimens.

Adapting Protocols or Models for Use in Insulin-Requiring Diabetes and Islet Transplant Recipients

The authors’ perspective is described regarding modifications made in their clinic to glucose challenge protocols and mathematical models in order to estimate insulin secretion, insulin sensitivity and glucose effectiveness in patients living with Insulin-Requiring Diabetes and patients who received Pancreatic Islet Transplants to treat Type I diabetes (T1D) with Impaired Awareness of Hypoglycemia. The evolutions are described of protocols and models for use in T1D, and Insulin-Requiring Type 2 Diabetes (T2D) that were the basis for studies in the Islet Recipients. In each group, the need for modifications, and how the protocols and models were adapted is discussed. How the ongoing application of the adaptations is clarifying the Islet pathophysiology in the Islet Transplant Recipients is outlined.

Mechanisms of Immunomodulation and Cytoprotection Conferred to Pancreatic Islet by Human Amniotic Epithelial Cells

Inhibiting pro-inflammatory cytokine activity can reverse inflammation mediated dysfunction of islet grafts. Human amniotic epithelial cells (hAECs) possess regenerative, immunomodulatory and anti-inflammatory properties. We hypothesized that hAECs could protect islets from cellular damage induced by pro-inflammatory cytokines. To verify our hypothesis hAECs monocultures, rat islets (RI), or RI-hAEC co-cultures where exposed to a pro-inflammatory cytokine cocktail (Interferon γ: IFN-γ, Tumor necrosis factor α: TNF-α and Interleukin-1β: IL-1β). The secretion of anti-inflammatory cytokines and gene expression changes in hAECs and viability and function of RI were evaluated. The expression of non-classical Major Histocompatibility Complex (MHC) class I molecules by hAECs cultured with various IFN-γ concentrations were assessed. Exposure to the pro-inflammatory cocktail significantly increased the secretion of the anti-inflammatory cytokines IL6, IL10 and G-CSF by hAECs, which was confirmed by upregulation of IL6, and IL10 gene expression. HLA-G, HLA-E and PDL-1 gene expression was also increased. This correlated with an upregulation of STAT1, STAT3 and NF-κB1gene expression levels. RI co-cultured with hAECs maintained normal function after cytokine exposure compared to RI cultured alone, and showed significantly lower apoptosis rate. Our results show that exposure to pro-inflammatory cytokines stimulates secretion of anti-inflammatory and immunomodulatory factors by hAECs through the JAK1/2 – STAT1/3 and the NF-κB1 pathways, which in turn protects islets against inflammation-induced damages. Integrating hAECs in islet transplants appears as a valuable strategy to achieve to inhibit inflammation mediated islet damage, prolong islet survival, improve their engraftment and achieve local immune protection allowing to reduce systemic immunosuppressive regimens.

Immunosuppressive PLGA TGF-β1 Microparticles Induce Polyclonal and Antigen-Specific Regulatory T Cells for Local Immunomodulation of Allogeneic Islet Transplants

Allogeneic islet transplantation is a promising cell-based therapy for Type 1 Diabetes (T1D). The long-term efficacy of this approach, however, is impaired by allorejection. Current clinical practice relies on long-term systemic immunosuppression, leading to severe adverse events. To avoid these detrimental effects, poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) were engineered for the localized and controlled release of immunomodulatory TGF-β1. The in vitro co-incubation of TGF-β1 releasing PLGA MPs with naïve CD4+ T cells resulted in the efficient generation of both polyclonal and antigen-specific induced regulatory T cells (iTregs) with robust immunosuppressive function. The co-transplantation of TGF-β1 releasing PLGA MPs and Balb/c mouse islets within the extrahepatic epididymal fat pad (EFP) of diabetic C57BL/6J mice resulted in the prompt engraftment of the allogenic implants, supporting the compatibility of PLGA MPs and local TGF-β1 release. The presence of the TGF-β1-PLGA MPs, however, did not confer significant graft protection when compared to untreated controls, despite measurement of preserved insulin expression, reduced intra-islet CD3+ cells invasion, and elevated CD3+Foxp3+ T cells at the peri-transplantation site in long-term functioning grafts. Examination of the broader impacts of TGF-β1/PLGA MPs on the host immune system implicated a localized nature of the immunomodulation with no observed systemic impacts. In summary, this approach establishes the feasibility of a local and modular microparticle delivery system for the immunomodulation of an extrahepatic implant site. This approach can be easily adapted to deliver larger doses or other agents, as well as multi-drug approaches, within the local graft microenvironment to prevent transplant rejection.

Mechanisms of immunomodulation and cytoprotection conferred to pancreatic islet by human amniotic epithelial cells

Inhibiting pro-inflammatory cytokine activity can reverse inflammation mediated dysfunction of islet grafts. Human amniotic epithelial cells (hAECs) possess regenerative, immunomodulatory and anti-inflammatory properties. We hypothesized that hAECs could protect islets from cellular damage induced by pro-inflammatory cytokines. To verify our hypothesis hAECs monocultures, rat islets (RI), or RI-hAEC co-cultures where exposed to a pro-inflammatory cytokine cocktail (Interferon γ: IFN-γ, Tumor necrosis factor α: TNF-α and Interleukin-1β: IL-1β). The secretion of anti-inflammatory cytokines and gene expression changes in hAECs and viability and function of RI were evaluated. The expression of non-classical Major Histocompatibility Complex (MHC) class I molecules by hAECs cultured with various IFN-γ concentrations were assessed. Exposure to the pro-inflammatory cocktail significantly increased the secretion of the anti-inflammatory cytokines IL6, IL10 and G-CSF by hAECs, which was confirmed by upregulation of IL6, and IL10 gene expression. HLA-G, HLA-E and PDL-1 gene expression was also increased. This correlated with an upregulation of STAT1, STAT3 and NF-κB1gene expression levels. RI co-cultured with hAECs maintained normal function after cytokine exposure compared to RI cultured alone, and showed significantly lower apoptosis rate. Our results show that exposure to pro-inflammatory cytokines stimulates secretion of anti-inflammatory and immunomodulatory factors by hAECs through the JAK1/2 – STAT1/3 and the NF-κB1 pathways, which in turn protects islets against inflammation-induced damages. Integrating hAECs in islet transplants appears as a valuable strategy to achieve to inhibit inflammation mediated islet damage, prolong islet survival, improve their engraftment and achieve local immune protection allowing to reduce systemic immunosuppressive regimens.

The Safety of Pharmacological and Surgical Treatment of Diabetes in Patients with Diabetic Retinopathy—A Review

Background. Diabetes mellitus (DM) is a non-infectious pandemic of the modern world; it is estimated that in 2045 it will affect 10% of the world’s population. As the prevalence of diabetes increases, the problem of its complications, including diabetic retinopathy (DR), grows. DR is a highly specific neurovascular complication of diabetes that occurs in more than one third of DM patients and accounts for 80% of complete vision loss cases in the diabetic population. We are currently witnessing many groundbreaking studies on new pharmacological and surgical methods of treating diabetes. Aim. The aim of the study is to assess the safety of pharmacological and surgical treatment of DM in patients with DR. Material and methods. An analysis of the data on diabetes treatment methods currently available in the world literature and their impact on the occurrence and progression of DR. Results. A rapid decrease in glycaemia leads to an increased occurrence and progression of DR. Its greatest risk accompanies insulin therapy and sulfonylurea therapy. The lowest risk of DR occurs with the use of SGLT2 inhibitors; the use of DPP-4 inhibitors and GLP-1 analogues is also safe. Patients undergoing pancreatic islet transplants or bariatric surgeries require intensive monitoring of the state of the eye, both in the perioperative and postoperative period. Conclusions. It is of utmost importance to individualize therapy in diabetic patients, in order to gradually achieve treatment goals with the use of safe methods and minimize the risk of development and progression of DR.

1093. Infectious Complications after Pancreatic Islet Transplantation

Background Despite the significant advancement in islet transplantation over the past three decades, our understanding of infectious complications post islet transplant remains limited. Methods This is a single center retrospective review of Islet transplant recipients at the University of Alberta between February 2006 and December 2015. All infectious episodes events occurring after transplant were categorized as opportunistic and non-opportunistic. Results We analyzed 142 patients receiving a median of 2 islet transplants per patient, with 18 patients receiving 1 transplant (13%), 77 (54%) 2, 33 (23%) 3, 13 (9%) 4 and 1(1%) 5 transplants. Median age at first transplant was 50 years and 85 (47%) were male. Lymphocyte depleting agent with thymoglobulin or alemtuzumab was used for induction in 94% in first and 53% in second transplant. CMV serostatus was CMV D+/R- 61 (43%), CMVD+/R+ 52 (37%), CMVD-/R+ 16 (11%) and CMVD-/R- 13 (9%). CMV infection occurred in 21 patients (15%) [CMVD+/R- 6 (9.8%) and CMVR+ 15 (22.1%), p=0.06]. Other opportunistic infections included VZV 7 (4.9%), Nocardia 3(2.1%), and Pneumocystis jirovecii pneumonia 1. Non-opportunistic infections included skin and soft tissue infection 14 (9.9%), urinary tract infection 11 (7.7%), pneumonia 7 (4.9%) clostridium difficile infection (CDI) 4 (2.8%), and non-CDI gastroenteritis 5 (3.5%) (Table 1). Table 1: Infectious Complication post islet transplant Conclusion Although the rate of infections after islet cell transplant is less frequent than other types of transplants, opportunistic infections, especially CMV, are not uncommon and should be considered in this setting. Disclosures Carols Cervera, MD, PHD, Merk (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member, Other Financial or Material Support, Lecture fees) James Shapiro, MD, PHD FRCS(Eng) FRCSC MSM FRSC, ViaCyte (Consultant) Dima Kabbani, MD, Merck (Research Grant or Support)

Islet Transplantation in Type 1 Diabetes Mellitus With Hypoglycaemic Unawareness

The primary indications for ICT in T1DM are glycaemic lability and hypoglycaemia unawareness. ICT is an effective, minimally invasive treatment for stabilising glycaemic control, correcting hypoglycaemia unawareness and improving quality of life even when exogenous insulin-independence is not fully achieved. However, the majority of patients require two islet transplants. The need for lifelong immunosuppression, in combination with the limited availability of donor pancreases, currently limits the wider application of ICT, particularly in the treatment of children newly diagnosed with T1DM. New technologies, including macro- and micro-encapsulation, xenotransplantation and stem cell-derived b cells offer hope for the future of b cell replacement. Yet, until then, a continued focus on optimising donor pancreases, improving the islet isolation procedure, use of novel immunosuppression, and understanding the mechanisms behind graft loss is required.

The Effects of Using Pancreases Obtained from Brain-Dead Donors for Clinical Islet Transplantation in Japan

Background: The pool of brain-dead donors (BDDs) was increased with the revision to the relevant law in 2010, and islet transplantation from BDDs was started in 2013. The present study assessed the influence of using pancreases from BDDs on islet transplantation in Japan. Methods: The donor information registered with the secretariat of islet transplants from 2012 was reviewed, and the results of 86 clinical islet isolations performed in Japan between 2003 and 2018 with non-heart-beating donors (NHBDs) (n = 71) and BDDs (n = 15) were investigated. Results: The number of cases for which donor information was registered with the secretariat of islet transplants increased to 1.84 cases/month from 2013 to 2018 in comparison to 1.44/month in 2012, when only NHBDs were used. The median pancreatic islet yield was 275,550 IEQ (Islet equivalents) in the NHBD group but 3,627,000 in the BDD group, which amounted to a statistically significant difference (p = 0.02). As a result, 38/71 cases (53.5%) were achieved successful islet isolation (>5000 IEQ per recipient weight (kg)) was achieved in 38/71 cases (53.5%) in the NHBD group, and 12/15 cases (80.0%) in the BDD group; thus, the rate of successful islet transplantation was higher in the BDD group. Conclusion: The use of pancreases from BDDs has increased the overall number of cases for which donor information is registered with the secretariat of islet transplants and has improved the performance of islet isolation, thereby increasing the probability of successfully achieving islet transplantation.