Third-Party Allogeneic Mesenchymal Stromal Cells Prevent Rejection in a Pre-sensitized High-Risk Model of Corneal Transplantation

High-risk cornea transplant recipients represent a patient population with significant un-met medical need for more effective therapies to prevent immunological graft rejection due to heightened anti-donor immune response. In this study, a rat model of pre-existing anti-donor immunity was developed in which corneal allografts were rejected earlier than in non-pre-sensitized recipients. In this model, third-party (non-donor, non-recipient strain) allogeneic mesenchymal stromal cells (allo-MSC) were administered intravenously 7 and 1 days prior to transplantation. Rejection-free graft survival to 30 days post-transplant improved from 0 to 63.6% in MSC-treated compared to vehicle-treated control animals (p = < 0.0001). Pre-sensitized animals that received third-party allo-MSC prior to transplantation had significantly higher proportions of CD45+CD11b+ B220+ monocytes in the lungs 24 h after the second MSC injection and significantly higher proportions of CD4+ FoxP3+ regulatory T cells in the graft-draining lymph nodes at the average day of rejection of control animals. In in vitro experiments, third-party allo-MSC polarized primary lung-derived CD11b/c+ myeloid cells to a more anti-inflammatory phenotype, as determined by cytokine profile and conferred them with the capacity to suppress T cell activation via prostaglandin E2 and TGFβ1. In experiments designed to further validate the clinical potential of the protocol, thawed cryopreserved, third-party allo-MSC were shown to be similarly potent at prolonging rejection-free corneal allograft survival as their freshly-cultured counterparts in the pre-sensitized high-risk model. Furthermore, thawed cryopreserved third-party allo-MSC could be co-administered with mycophenolate mofetil without adversely affecting their immunomodulatory function. In conclusion, a clinically-relevant protocol consisting of two intravenous infusions of third-party allo-MSC during the week prior to transplantation, exerts a potent anti-rejection effect in a pre-sensitized rat model of high-risk corneal allo-transplantation. This immune regulatory effect is likely to be mediated in the immediate post-transplant period through the promotion, by allo-MSC, of alternatively-activated macrophages in the lung and, later, by enhanced regulatory T-cell numbers

Clinical and Economic Evaluation of a Proteomic Biomarker Preterm Birth Risk Predictor: Cost-Effectiveness Modeling of Prenatal Interventions Applied to Predicted Higher-Risk Pregnancies Within a Large and Diverse Cohort

Objectives: Preterm birth occurs in more than 10% of U.S. births and is the leading cause of U.S. neonatal deaths, with estimated annual costs exceeding $25 billion USD. Using real-world data, we modeled the potential clinical and economic utility of a prematurity-reduction program comprising screening in a racially and ethnically diverse population with a validated proteomic biomarker risk predictor, followed by case management with or without pharmacological treatment. Methods: The ACCORDANT microsimulation model used individual patient data from a prespecified, randomly selected sub-cohort (N = 847) of a multicenter, observational study of U.S. subjects receiving standard obstetric care with masked risk predictor assessment (TREETOP; NCT02787213). All subjects were included in three arms across 500 simulated trials: standard of care (SoC, control); risk predictor/case management comprising increased outreach, education and specialist care (RP-CM, active); and multimodal management (risk predictor/case management with pharmacological treatment) (RP-MM, active). In the active arms, only subjects stratified as higher risk by the predictor were modeled as receiving the intervention, whereas lower-risk subjects received standard care. Higher-risk subjects\u27 gestational ages at birth were shifted based on published efficacies, and dependent outcomes, calibrated using national datasets, were changed accordingly. Subjects otherwise retained their original TREETOP outcomes. Arms were compared using survival analysis for neonatal and maternal hospital length of stay, bootstrap intervals for neonatal cost, and Fisher\u27s exact test for neonatal morbidity/mortality (significance, p \u3c .05). Results: The model predicted improvements for all outcomes. RP-CM decreased neonatal and maternal hospital stay by 19% (p = .029) and 8.5% (p = .001), respectively; neonatal costs\u27 point estimate by 16% (p = .098); and moderate-to-severe neonatal morbidity/mortality by 29% (p = .025). RP-MM strengthened observed reductions and significance. Point estimates of benefit did not differ by race/ethnicity. Conclusions: Modeled evaluation of a biomarker-based test-and-treat strategy in a diverse population predicts clinically and economically meaningful improvements in neonatal and maternal outcomes

Bi-allelic Loss-of-Function CACNA1B Mutations in Progressive Epilepsy-Dyskinesia.

The occurrence of non-epileptic hyperkinetic movements in the context of developmental epileptic encephalopathies is an increasingly recognized phenomenon. Identification of causative mutations provides an important insight into common pathogenic mechanisms that cause both seizures and abnormal motor control. We report bi-allelic loss-of-function CACNA1B variants in six children from three unrelated families whose affected members present with a complex and progressive neurological syndrome. All affected individuals presented with epileptic encephalopathy, severe neurodevelopmental delay (often with regression), and a hyperkinetic movement disorder. Additional neurological features included postnatal microcephaly and hypotonia. Five children died in childhood or adolescence (mean age of death: 9 years), mainly as a result of secondary respiratory complications. CACNA1B encodes the pore-forming subunit of the pre-synaptic neuronal voltage-gated calcium channel Cav2.2/N-type, crucial for SNARE-mediated neurotransmission, particularly in the early postnatal period. Bi-allelic loss-of-function variants in CACNA1B are predicted to cause disruption of Ca2+ influx, leading to impaired synaptic neurotransmission. The resultant effect on neuronal function is likely to be important in the development of involuntary movements and epilepsy. Overall, our findings provide further evidence for the key role of Cav2.2 in normal human neurodevelopment.MAK is funded by an NIHR Research Professorship and receives funding from the Wellcome Trust, Great Ormond Street Children's Hospital Charity, and Rosetrees Trust. E.M. received funding from the Rosetrees Trust (CD-A53) and Great Ormond Street Hospital Children's Charity. K.G. received funding from Temple Street Foundation. A.M. is funded by Great Ormond Street Hospital, the National Institute for Health Research (NIHR), and Biomedical Research Centre. F.L.R. and D.G. are funded by Cambridge Biomedical Research Centre. K.C. and A.S.J. are funded by NIHR Bioresource for Rare Diseases. The DDD Study presents independent research commissioned by the Health Innovation Challenge Fund (grant number HICF-1009-003), a parallel funding partnership between the Wellcome Trust and the Department of Health, and the Wellcome Trust Sanger Institute (grant number WT098051). We acknowledge support from the UK Department of Health via the NIHR comprehensive Biomedical Research Centre award to Guy's and St. Thomas' National Health Service (NHS) Foundation Trust in partnership with King's College London. This research was also supported by the NIHR Great Ormond Street Hospital Biomedical Research Centre. J.H.C. is in receipt of an NIHR Senior Investigator Award. The research team acknowledges the support of the NIHR through the Comprehensive Clinical Research Network. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, Department of Health, or Wellcome Trust. E.R.M. acknowledges support from NIHR Cambridge Biomedical Research Centre, an NIHR Senior Investigator Award, and the University of Cambridge has received salary support in respect of E.R.M. from the NHS in the East of England through the Clinical Academic Reserve. I.E.S. is supported by the National Health and Medical Research Council of Australia (Program Grant and Practitioner Fellowship)

Anti-Donor Immune Responses Elicited by Allogeneic Mesenchymal Stem Cells and Their Extracellular Vesicles: Are We Still Learning?

Mesenchymal stromal cells (MSC) have been used to treat a broad range of disease indications such as acute and chronic inflammatory disorders, autoimmune diseases, and transplant rejection due to their potent immunosuppressive/anti-inflammatory properties. The breadth of their usage is due in no small part to the vast quantity of published studies showing their ability to modulate multiple immune cell types of both the innate and adaptive immune response. While patient-derived (autologous) MSC may be the safer choice in terms of avoiding unwanted immune responses, factors including donor comorbidities may preclude these cells from use. In these situations, allogeneic MSC derived from genetically unrelated individuals must be used. While allogeneic MSC were initially believed to be immune-privileged, substantial evidence now exists to prove otherwise with multiple studies documenting specific cellular and humoral immune responses against donor antigens following administration of these cells. In this article, we will review recent published studies using non-manipulated, inflammatory molecule-activated (licensed) and differentiated allogeneic MSC, as well as MSC extracellular vesicles focusing on the immune responses to these cells and whether or not such responses have an impact on allogeneic MSC-mediated safety and efficacy

A 3D View of Colorectal Cancer Models in Predicting Therapeutic Responses and Resistance

Although there have been many advances in recent years for the treatment of colorectal cancer (CRC), it still remains the third most common cause of cancer-related deaths worldwide. Many patients with late stage CRC display resistance to multiple different therapeutics. An important aspect in developing effective therapeutics for CRC patients is understanding the interactions that take place in the tumor microenvironment (TME), as it has been shown to contribute to drug resistance in vivo. Much research over the past 100 years has focused on 2D monolayer cultures or in vivo studies, however, the efficacy in translating these to the clinic is very low. More recent studies are turning towards developing an effective 3D model of CRC that is clinically relevant, that can recapitulate the TME in vitro and bridge the gap between 2D cultures and in vivo studies, with the aim of reducing the use of animal models in the future. This review summarises the advantages and limitations of different 3D CRC models. It emphasizes how different 3D models may be optimised to study cellular and extracellular interactions that take place in the TME of CRC in an effort to allow the development of more translatable effective treatment options for patients

Anti-donor immune responses elicited by allogeneic mesenchymal stem cells and their extracellular vesicles: are we still learning?

Mesenchymal stromal cells (MSC) have been used to treat a broad range of disease indications such as acute and chronic inflammatory disorders, autoimmune diseases, and transplant rejection due to their potent immunosuppressive/anti-inflammatory properties. The breadth of their usage is due in no small part to the vast quantity of published studies showing their ability to modulate multiple immune cell types of both the innate and adaptive immune response. While patient-derived (autologous) MSC may be the safer choice in terms of avoiding unwanted immune responses, factors including donor comorbidities may preclude these cells from use. In these situations, allogeneic MSC derived from genetically unrelated individuals must be used. While allogeneic MSC were initially believed to be immune-privileged, substantial evidence now exists to prove otherwise with multiple studies documenting specific cellular and humoral immune responses against donor antigens following administration of these cells. In this article, we will review recent published studies using non-manipulated, inflammatory molecule-activated (licensed) and differentiated allogeneic MSC, as well as MSC extracellular vesicles focusing on the immune responses to these cells and whether or not such responses have an impact on allogeneic MSC-mediated safety and efficacy

TNF-a/IL-1ß-licensed mesenchymal stromal cells promote corneal allograft survival via myeloid cell-mediated induction of Foxp3+ regulatory T cells in the lung.

Mesenchymal stromal cells (MSCs) have shown promise as a therapy for immune-mediated disorders, including transplant rejection. Our group previously demonstrated the efficacy of pretransplant, systemic administration of allogeneic but not syngeneic MSCs in a rat cornea transplant model. The aim of this study was to enhance the immunomodulatory capacity of syngeneic MSCs. In vitro, MSCs licensed with TNF-¿/IL-1ß (MSCsTNF-¿/IL-1ß) suppress syngeneic lymphocyte proliferation via NO production. In vivo, when administered post-transplantation, nonlicensed syngeneic MSCs improved graft survival from 0 to 50% and MSCsTNF-¿/IL-1ß, in an NO-dependent manner, improved survival to 70%. Improved survival was associated with increased CD4+CD25+forkhead box P3+ regulatory T (Treg) cells and decreased proinflammatory cytokine expression in the draining lymph node. MSCsTNF-¿/IL-1ß demonstrated a more potent immunomodulatory capacity compared with nonlicensed MSCs, promoting an immune-regulatory CD11b+B220+ monocyte/macrophage population and significantly expanding Treg cells in the lungs and spleen. Ex vivo, we observed that lung-derived myeloid cells act as intermediaries of MSC immunomodulatory function. MSC-conditioned myeloid cells suppressed stimulated lymphocyte proliferation and promoted expansion of Treg cells from naive lymphocytes. This work illustrates how syngeneic MSC therapy can be enhanced by licensing and optimization of timing strategies and further highlights the important role of myeloid cells in mediating MSC immunomodulatory capacity.-Murphy, N., Treacy, O., Lynch, K., Morcos, M., Lohan, P., Howard, L., Fahy, G., Griffin, M. D., Ryan, A. E., Ritter, T. TNF-¿/IL-1ß-licensed mesenchymal stromal cells promote corneal allograft survival via myeloid cell-mediated induction of Foxp3+ regulatory T cells in the lung.This study was supported by a Science Foundation Ireland Investigator Award (grant number 12/IA/1624; NM, OT, KL, MM, PL, MDG, TR). This work was also supported by grants from the Health Research Board of Ireland (grant number HRA_POR/2013/341) (NM, MDG, TR), a Science Foundation Ireland Starting Investigator Grant (grant number 15/SIRG/3456; AR), by the EU FP7 Collaborative Health Project VISICORT (grant number 602470; NM, 691 PL, MDG, TR) and the European Regional Development Fund. The authors wish to acknowledge the advice, assistance and technical expertise of Ms. Georgina Shaw NUI Galway. All flow cytometry experiments were performed in the NUI Galway Flow Cytometry Core Facility which is supported by funds from NUI Galway, Science Foundation Ireland, the Irish Government’s Programme for Research in Third Level Institutions, Cycle 5 and the European Regional Development Fund. The authors acknowledge the facilities as well as the scientific and technical assistance of the National Centre for Biomedical Engineering Science Genomics Facility at the National University of Ireland Galway, a facility that is funded by National University of Ireland Galway and the Irish Government’s Programme for Research in Third Level Institutions, Cycles 4 and 5, National Development Plan 2007–2013.peer-reviewe

Anti-Donor Immune Responses Elicited by Allogeneic Mesenchymal Stem Cells and Their Extracellular Vesicles: Are We Still Learning?

Mesenchymal stromal cells (MSC) have been used to treat a broad range of disease indications such as acute and chronic inflammatory disorders, autoimmune diseases, and transplant rejection due to their potent immunosuppressive/anti-inflammatory properties. The breadth of their usage is due in no small part to the vast quantity of published studies showing their ability to modulate multiple immune cell types of both the innate and adaptive immune response. While patient-derived (autologous) MSC may be the safer choice in terms of avoiding unwanted immune responses, factors including donor comorbidities may preclude these cells from use. In these situations, allogeneic MSC derived from genetically unrelated individuals must be used. While allogeneic MSC were initially believed to be immune-privileged, substantial evidence now exists to prove otherwise with multiple studies documenting specific cellular and humoral immune responses against donor antigens following administration of these cells. In this article, we will review recent published studies using non-manipulated, inflammatory molecule-activated (licensed) and differentiated allogeneic MSC, as well as MSC extracellular vesicles focusing on the immune responses to these cells and whether or not such responses have an impact on allogeneic MSC-mediated safety and efficacy.OT and TR are supported by a Science Foundation Ireland grants (12/IA/1624), PL, MG, and TR are supported by EU FP7 [Collaborative Health Project VISICORT (grant number 602470)], Science Foundation Ireland [REMEDI Strategic Research Cluster (grant number 09/SRC-B1794); MG is supported by CÚRAM Research Centre (grant number 13/RC/2073)]; the European Commission [Horizon 2020 Collaborative Health Project NEPHSTROM (grant number 634086), and the European Regional Development Fund. AR is supported by Irish Cancer Society Fellowship (CRF12RYA) and Science Foundation Ireland Starting Investigator Grant (15/SIRG/3456).peer-reviewe