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The extracellular RNA communication consortium (ERCC) is an NIH-funded program aiming to promote the development of new technologies, resources, and knowledge about exRNAs and their carriers. After Phase 1 (2013-2018), Phase 2 of the program (ERCC2, 2019-2023) aims to fill critical gaps in knowledge and technology to enable rigorous and reproducible methods for separation and characterization of both bulk populations of exRNA carriers and single EVs. ERCC2 investigators are also developing new bioinformatic pipelines to promote data integration through the exRNA atlas database. ERCC2 has established several Working Groups (Resource Sharing, Reagent Development, Data Analysis and Coordination, Technology Development, nomenclature, and Scientific Outreach) to promote collaboration between ERCC2 members and the broader scientific community. We expect that ERCC2's current and future achievements will significantly improve our understanding of exRNA biology and the development of accurate and efficient exRNA-based diagnostic, prognostic, and theranostic biomarker assays.

Background: Although pancreatic islet transplantation is becoming an effective therapeutic option for patients with type 1 diabetes (T1D) who suffer from a substantially impaired awareness of hypoglycemia, its application is limited due to the lack of donors. Thus, pig‐to‐human islet xenotransplantation has been regarded as a promising alternative due to the unlimited number of "donor organs." Long‐term xenogeneic islet graft survival in pig‐to‐non‐human primate (NHP) models has mainly been achieved by administering the anti‐CD154 mAb‐based immunosuppressant regimen. Since the anti‐CD154 mAb treatment has been associated with unexpected fatal thromboembolic complications in clinical trials, the establishment of a new immunosuppressant regimen that is able to be directly applied in clinical trials is an urgent need. Methods: We assessed an immunosuppressant regimen composed of clinically available agents at porcine islet transplantation in consecutive diabetic NHPs. Results: Porcine islet graft survival in consecutive diabetic NHPs (n = 7; >222, >200, 181, 89, 62, 55, and 34 days) without severe adverse events. Conclusion: We believe that our study could contribute greatly to the initiation of islet xenotransplantation clinical trials. [ABSTRACT FROM AUTHOR]

Background: Xenogeneic islet transplantation using porcine pancreata has been a promising option for substituting human islet transplantation. Moreover, recent advances in pre‐clinical results have put islet xenotransplantation closer to the possibility of clinical application. While preparing for the era of clinical xenotransplantation, developing non‐invasive immune monitoring method which could predict the graft fate could benefit the patient. However, there are few reports showing predictive immune parameters associated with the fate of the graft in islet xenotransplantation. Methods: The absolute number and ratio of T‐cell subsets have been measured via flow cytometry from the peripheral blood of 16 rhesus monkeys before and after porcine islet xenotransplantation. The correlation between the graft survival and the absolute number or ratio of T cells was retrospectively analyzed. Results: The ratio of CD4+ versus CD8+ T cells was significantly reduced due to CD8+ effector memory cells' increase. Correlation analyses revealed that CD4+/CD8+, CD4+/CD8+ naïve, CD4+ naïve/CD8+ naïve, and CD4+ central memory/CD8+ naïve cell ratios negatively correlated with the duration of graft survival. Conversely, further analyses discovered strong, positive correlation of CD4+/CD8+ cell ratios within the early graft‐rejected monkeys (≤60 days). Conclusions: This retrospective study demonstrated that CD4+/CD8+ ratios correlated with graft survival, especially in recipients which rejected the graft in early post‐transplantation periods. CD4+/CD8+ ratios could be used as a surrogate marker to predict the graft fate in pig‐to‐NHP islet xenotransplantation. [ABSTRACT FROM AUTHOR]

Abstract: Tacrolimus‐associated thrombotic microangiopathy (TA‐TMA) is a rare complication. TA‐TMA is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and organ damage due to thrombus. We report asymptomatic TA‐TMA diagnosed by laboratory tests in pig‐to‐rhesus corneal xenotransplantation. Corneal transplantation had been conducted from a wild‐type SNU miniature pig to a rhesus macaque. The veterinary records were retrospectively reviewed in this case. The immunosuppressive regimen consisted of rituximab, basiliximab, and IVIg as inductive therapies, and steroids with tacrolimus (0.1 mg/kg/day) as maintenance therapies. Although there were no clinical symptoms, increased levels of lactate dehydrogenase, total bilirubin, blood urea nitrogen, and creatinine and decreased levels of hemoglobin and platelet were observed in laboratory tests on Day (D) 61. Systemic TA‐TMA was tentatively diagnosed. Tacrolimus was discontinued starting on D71. Dalteparin, clopidogrel bisulfate (D77‐D99), and IVIg (D72) were administered as a conservative treatment. Abnormal laboratory results were reversed on D99. When low‐dose tacrolimus (0.07 mg/kg/day) was re‐administered on D131 to prevent rejection of the graft, TMA was detected again by laboratory tests on D161, confirming the initial diagnosis. Discontinuation of tacrolimus on D162 and re‐administration of Dalteparin (D161‐D196) corrected the laboratory values on D161. This report shows that in pig‐to‐rhesus corneal xenotransplantation, clinically asymptomatic TMA can be induced by tacrolimus, and the discontinuation of tacrolimus and administration of anticoagulant seems sufficient to correct the laboratory TMA. [ABSTRACT FROM AUTHOR]

Abstract: Background: Pancreatic islet transplantation is currently proven as a promising treatment for type 1 diabetes patients with labile glycemic control and severe hypoglycemia unawareness. Upon islet transplantation, revascularization is essential for proper functioning of the transplanted islets. As IL‐6 is important for endothelial cell survival and systemic inflammation related to xenograft, the effect of IL‐6 receptor antagonist, tocilizumab, on revascularization of the transplanted islets was examined in pig to non‐human primate islet xenotransplantation model. Also, the endothelial cell origin in a new vessel of the transplanted pig islets was determined. Methods: Pig islets were isolated from designated pathogen‐free (DPF) SNU miniature pigs and transplanted via portal vein into five streptozotocin‐induced diabetic monkeys. One group (n = 2, basal group) was treated with anti‐thymoglobulin (ATG), anti‐CD40 antibody (2C10R4), sirolimus, and tacrolimus, and the other group was additionally given tocilizumab on top of basal immunosuppression (n = 3, Tocilizumab group). To confirm IL‐6 blocking effect, C‐reactive protein (CRP) levels and serum IL‐6 concentration were measured. Scheduled biopsy of the margin of the posterior segment right lobe inferior of the liver was performed at 3 weeks after transplantation to assess the degree of revascularization of the transplanted islets. Immunohistochemical staining using anti‐insulin, anti‐CD31 antibodies, and lectin IB4 was conducted to find the origin of endothelial cells in the islet graft. Results: CRP significantly increased at 1~2 days after transplantation in Basal group, but not in Tocilizumab group, and higher serum IL‐6 concentration was measured in latter group, showing the biological potency of tocilizumab. In Basal group, well‐developed endothelial cells were observed on the peri‐ and intraislet area, whereas the number of CD31+ cells in the intraislet space was significantly reduced in Tocilizumab group. Finally, new endothelial cells in the pig islet graft were positive for CD31, but not for lectin IB4, suggesting that they are originated from the recipient monkey. Conclusions: Our results demonstrated that tocilizumab can delay revascularization of the transplanted islet, although this effect had no significant correlation to the overall islet graft survival. In the pig to NHP islet xenotransplantation model, the endothelial cells from recipient monkey form new blood vessels in and around pig islets. [ABSTRACT FROM AUTHOR]

Abstract: Background: Islet transplantation is an effective therapy for selected patients with type 1 diabetes with labile glycemic control and hypoglycemic unawareness, but donor organs are limited. Islet xenotransplantation using porcine islets will potentially solve this problem. Although successful proof of concept studies using clinically inapplicable anti‐CD154 monoclonal antibody (mAb) in pig‐to‐non‐human primate (NHP) islet xenotransplantation has been demonstrated by several groups worldwide, potentially clinically applicable anti‐CD40 (2C10R4) mAb‐based studies have not been reported. Methods: Nine streptozotocin (STZ)‐induced diabetic rhesus monkeys were transplanted with adult porcine islets isolated from designated pathogen‐free (DPF) miniature pigs. They were treated with anti‐CD40 mAb‐based immunosuppressive regimen and were divided into 3 groups: anti‐CD40 only group (n = 2), belatacept group (anti‐CD40 mAb+belatacept, n = 2), and tacrolimus group (anti‐CD40 mAb+tacrolimus, n = 5). All monkeys received anti‐thymocyte globulin (ATG), cobra venom factor (CVF), adalimumab, and sirolimus. Blood glucose levels (BGL) and serum porcine C‐peptide concentrations were measured. Humoral and cellular immune responses were assessed by ELISA and ELISPOT, respectively. Liver biopsy and subsequent immunohistochemistry were conducted. Results: All animals restored normoglycemia immediately after porcine islet transplantation and finished the follow‐up without any severe adverse effects except for one animal (R092). Most animals maintained their body weight. Median survival, as defined by a serum porcine C‐peptide concentration of >0.15 ng/mL, was 31, 27, and 60 days for anti‐CD40 only, belatacept, and tacrolimus groups, respectively. Anti‐αGal IgG levels in serum and the number of interferon‐γ secreting T cells in peripheral blood mononuclear cells did not increase in most animals. Conclusion: These results showed that anti‐CD40 mAb combined with tacrolimus was effective in prolonging porcine islet graft survival, but anti‐CD40 mAb was not as effective as anti‐CD154 mAb in terms of preventing early islet loss. [ABSTRACT FROM AUTHOR]

Pig‐to‐nonhuman primate (NHP) islet transplantation has been widely conducted as a preclinical xenotransplantation model prior to human clinical trial. Portal vein thrombosis is one of the complications associated with islet infusion through the portal vein into the liver. Here, we briefly report severe case of ascites formation accompanied by portal vein thrombi after pig‐to‐NHP islet xenotransplantation in a rhesus monkey. Meticulous prophylactic treatment such as continuous heparin infusion should be implemented to prevent portal vein thrombi in pig‐to‐NHP islet transplantation models. [ABSTRACT FROM AUTHOR]

Background: Xenogeneic islet transplantation using porcine pancreata has been a promising option for substituting human islet transplantation. Moreover, recent advances in pre-clinical results have put islet xenotransplantation closer to the possibility of clinical application. While preparing for the era of clinical xenotransplantation, developing non-invasive immune monitoring method which could predict the graft fate could benefit the patient. However, there are few reports showing predictive immune parameters associated with the fate of the graft in islet xenotransplantation., Methods: The absolute number and ratio of T-cell subsets have been measured via flow cytometry from the peripheral blood of 16 rhesus monkeys before and after porcine islet xenotransplantation. The correlation between the graft survival and the absolute number or ratio of T cells was retrospectively analyzed., Results: The ratio of CD4 + versus CD8 + T cells was significantly reduced due to CD8 + effector memory cells' increase. Correlation analyses revealed that CD4 + /CD8 + , CD4 + /CD8 + naïve, CD4 + naïve/CD8 + naïve, and CD4 + central memory/CD8 + naïve cell ratios negatively correlated with the duration of graft survival. Conversely, further analyses discovered strong, positive correlation of CD4 + /CD8 + cell ratios within the early graft-rejected monkeys (≤60 days)., Conclusions: This retrospective study demonstrated that CD4 + /CD8 + ratios correlated with graft survival, especially in recipients which rejected the graft in early post-transplantation periods. CD4 + /CD8 + ratios could be used as a surrogate marker to predict the graft fate in pig-to-NHP islet xenotransplantation., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Senescent T cells have been implicated in chronic inflammatory and cardiovascular diseases. In this study, we explored the relationship between senescent T cells and glycemic status in a cohort of 805 participants by investigating the frequency of CD57 + or CD28 null senescent T cells in peripheral blood. Participants with normal glucose tolerance (NGT) with follow-up data ( N = 149) were included to determine whether hyperglycemia (prediabetes or type 2 diabetes) developed during follow-up (mean 2.3 years). CD8 + CD57 + and CD8 + CD28 null T-cell frequencies were significantly higher in prediabetes and type 2 diabetes compared with NGT. Increased CD57 + or CD28 null cells in the CD8 + T-cell subset were independently associated with hyperglycemia. Furthermore, among participants with baseline NGT, the frequency of CD8 + CD57 + T cells was an independent predictor of hyperglycemia development. Immunofluorescent analyses confirmed that CD8 + CD57 + T-cell infiltration was increased in visceral adipose tissue of patients with prediabetes or type 2 diabetes compared with those with NGT. Our data suggest that increased frequency of senescent CD8 + T cells in the peripheral blood is associated with development of hyperglycemia., (© 2018 by the American Diabetes Association.)