Infusion of third-party mesenchymal stem cells after liver transplantation: a phase-1, open-label, clinical study

peer reviewedBackground: Mesenchymal stromal cells (MSC) are multipotent bone mar- row progenitors that have demonstrated significant immunosuppressive effects in various in vivo and in vitro studies. This study aimed to be the first evaluation of the safety and tolerability of MSC infusion after liver transplantation in a prospective, controlled phase-1 study. Methods: 10 liver transplant recipients under standard immunosuppression (TAC-MMF-low dose steroids until day 30) received 1.5–3 9 106/kg third party MSC on post-operative day 3 ` 2. These patients were prospectively compared to a group of 10 control liver recipients. Primary endpoints were MSC infusion toxicity, and incidence of cancer and opportunistic infections at month 6. Secondary endpoints were patient and graft survivals and rejection at month 6, as well as the effects of MSC on recipients’ immune function and on immunohistology of at month 6 graft biopsies. Results: No MSC infusional toxicity was observed. Both groups were comparable in terms of donor and recipient characteristics. There was no difference in primary end-points between control and MSC groups. No patient developed de novo cancer. There was no statistical difference in patient and graft survivals or in rejection rates. There was no graft rejection in the MSC group. Month-6 graft biopsies were not different according to Banff and fibrosis scores. Discussion: This phase 1 study showed excellent tolerability and safety of a single infusion of third-party MSC after liver transplantation. There were no graft safety issues and no excess of immunosuppression after MSC injection. Further analyses of consequences of MSC injection on the immune profile are needed. The possibility of avoiding calcineurin-inhibitors with repeated MSC injections as main immunosuppressive therapy and/of tolerance induction by MSC infusion should be investigated by further studies. This study is in part supported by an ESOT Senior Clinical Research Grant and by the University of Liege

Infusion of third-party mesenchymal stem cells after liver transplantation: a phase-1, open-label, clinical study

peer reviewedBackground: Mesenchymal stromal cells (MSC) are multipotent bone mar- row progenitors that have demonstrated significant immunosuppressive effects in various in vivo and in vitro studies. This study aimed to be the first evaluation of the safety and tolerability of MSC infusion after liver transplantation in a prospective, controlled phase-1 study. Methods: 10 liver transplant recipients under standard immunosuppression (TAC-MMF-low dose steroids until day 30) received 1.5–3 9 106/kg third party MSC on post-operative day 3 ` 2. These patients were prospectively compared to a group of 10 control liver recipients. Primary endpoints were MSC infusion toxicity, and incidence of cancer and opportunistic infections at month 6. Secondary endpoints were patient and graft survivals and rejection at month 6, as well as the effects of MSC on recipients’ immune function and on immunohistology of at month 6 graft biopsies. Results: No MSC infusional toxicity was observed. Both groups were comparable in terms of donor and recipient characteristics. There was no difference in primary end-points between control and MSC groups. No patient developed de novo cancer. There was no statistical difference in patient and graft survivals or in rejection rates. There was no graft rejection in the MSC group. Month-6 graft biopsies were not different according to Banff and fibrosis scores. Discussion: This phase 1 study showed excellent tolerability and safety of a single infusion of third-party MSC after liver transplantation. There were no graft safety issues and no excess of immunosuppression after MSC injection. Further analyses of consequences of MSC injection on the immune profile are needed. The possibility of avoiding calcineurin-inhibitors with repeated MSC injections as main immunosuppressive therapy and/of tolerance induction by MSC infusion should be investigated by further studies. This study is in part supported by an ESOT Senior Clinical Research Grant and by the University of Liege

Hepatitis C Virus Reveals a Novel Early Control in Acute Immune Response

Recognition of viral RNA structures by the intracytosolic RNA helicase RIG-I triggers induction of innate immunity. Efficient induction requires RIG-I ubiquitination by the E3 ligase TRIM25, its interaction with the mitochondria-bound MAVS protein, recruitment of TRAF3, IRF3- and NF-κB-kinases and transcription of Interferon (IFN). In addition, IRF3 alone induces some of the Interferon-Stimulated Genes (ISGs), referred to as early ISGs. Infection of hepatocytes with Hepatitis C virus (HCV) results in poor production of IFN despite recognition of the viral RNA by RIG-I but can lead to induction of early ISGs. HCV was shown to inhibit IFN production by cleaving MAVS through its NS3/4A protease and by controlling cellular translation through activation of PKR, an eIF2α-kinase containing dsRNA-binding domains (DRBD). Here, we have identified a third mode of control of IFN induction by HCV. Using HCVcc and the Huh7.25.CD81 cells, we found that HCV controls RIG-I ubiquitination through the di-ubiquitine-like protein ISG15, one of the early ISGs. A transcriptome analysis performed on Huh7.25.CD81 cells silenced or not for PKR and infected with JFH1 revealed that HCV infection leads to induction of 49 PKR-dependent genes, including ISG15 and several early ISGs. Silencing experiments revealed that this novel PKR-dependent pathway involves MAVS, TRAF3 and IRF3 but not RIG-I, and that it does not induce IFN. Use of PKR inhibitors showed that this pathway requires the DRBD but not the kinase activity of PKR. We then demonstrated that PKR interacts with HCV RNA and MAVS prior to RIG-I. In conclusion, HCV recruits PKR early in infection as a sensor to trigger induction of several IRF3-dependent genes. Among those, ISG15 acts to negatively control the RIG-I/MAVS pathway, at the level of RIG-I ubiquitination.These data give novel insights in the machinery involved in the early events of innate immune response

Hepatitis C Virus Controls Interferon Production through PKR Activation

Hepatitis C virus is a poor inducer of interferon (IFN), although its structured viral RNA can bind the RNA helicase RIG-I, and activate the IFN-induction pathway. Low IFN induction has been attributed to HCV NS3/4A protease-mediated cleavage of the mitochondria-adapter MAVS. Here, we have investigated the early events of IFN induction upon HCV infection, using the cell-cultured HCV JFH1 strain and the new HCV-permissive hepatoma-derived Huh7.25.CD81 cell subclone. These cells depend on ectopic expression of the RIG-I ubiquitinating enzyme TRIM25 to induce IFN through the RIG-I/MAVS pathway. We observed induction of IFN during the first 12 hrs of HCV infection, after which a decline occurred which was more abrupt at the protein than at the RNA level, revealing a novel HCV-mediated control of IFN induction at the level of translation. The cellular protein kinase PKR is an important regulator of translation, through the phosphorylation of its substrate the eIF2α initiation factor. A comparison of the expression of luciferase placed under the control of an eIF2α-dependent (IRESEMCV) or independent (IRESHCV) RNA showed a specific HCV-mediated inhibition of eIF2α-dependent translation. We demonstrated that HCV infection triggers the phosphorylation of both PKR and eIF2α at 12 and 15 hrs post-infection. PKR silencing, as well as treatment with PKR pharmacological inhibitors, restored IFN induction in JFH1-infected cells, at least until 18 hrs post-infection, at which time a decrease in IFN expression could be attributed to NS3/4A-mediated MAVS cleavage. Importantly, both PKR silencing and PKR inhibitors led to inhibition of HCV yields in cells that express functional RIG-I/MAVS. In conclusion, here we provide the first evidence that HCV uses PKR to restrain its ability to induce IFN through the RIG-I/MAVS pathway. This opens up new possibilities to assay PKR chemical inhibitors for their potential to boost innate immunity in HCV infection

Contrôle de l'induction d'interféron par le virus de l'hépatite C (rôle des protéines PKR et ISG15)

La production d interféron (IFN) permet l activation de la réponse immune innée de l hôte contre les infections. De nombreux virus à ARN déclenchent cette synthèse, via l ARN hélicase cellulaire RIG-I. Celle-ci doit être ubiquitinée pour interagir avec MAVS, une protéine liée aux mitochondries et activer la voie de signalisation conduisant à la transcription d IFN et de certains gènes appellés ISGs précoces. L ARN du virus de l hépatite C (VHC) est reconnu par RIG-I mais ce virus induit très peu l IFN. Une raison en est la capacité de sa protéase NS3/4A à cliver MAVS. Paradoxalement, l infection par le VHC déclenche la synthèse d ISGs précoces. Dans ce travail, nous avons identifié deux nouveaux points de contrôle de l induction d IFN par le VHC, avant clivage de MAVS par NS3/4A et expliqué le mécanisme d induction d ISGs précoces. En utilisant le modèle d infection des cellules Huh7.25.CD81 par le VHC recombinant JFH1, nous avons montré que le VHC active transitoirement la PKR, une eIF2 kinase cellulaire pour inhiber la synthèse protéique générale, dont celle d IFN, sans affecter sa propre traduction. Nous avons ensuite montré que l ubiquitination de RIG-I est inhibée par ISG15, une protéine di-ubiquitine like. Enfin, nous avons montré que le VHC déclenche la synthèse d ISG15 et d autres ISGs précoces, mais non celle d IFN, via une nouvelle voie de signalisation qui utilise la PKR comme adaptateur pour recruter MAVS. Nos résultats démontrent le rôle proviral de PKR et ISG15 et ouvrent la voie à l utilisation d inhibiteurs de la PKR pour bloquer l infection par le VHCPARIS-BIUSJ-Biologie recherche (751052107) / SudocSudocFranceF

Infusion of third-party mesenchymal stream cells after liver transplantation: a phase-1, open-label, clinical study

Background: Mesenchymal stromal cells (MSC) are multipotent bone marrow progenitors that have demonstrated significant immunosuppressive effects in various in vivo and in vitro studies. This study aimed to be the first evaluation of the safety and tolerability of MSC infusion after liver transplantation in a prospective, controlled phase-1 study. This study aimed to be the first evaluation of the safety and tolerability of MSC infusion after liver transplantation in a prospective, controlled phase-1 study. Patients & Methods: Clinical grade MSCs were locally collected from the bone marrow of unrelated healthy donors. They were cultured in a GMP-compliant lab, underwent extensive quality controls and were frozen for storage in a MSC bank. When needed for patient treatment, MSC were thawed and intravenously injected into patients. 10 liver transplant recipients under standard immunosuppression (TAC-MMF-low dose steroids until day 30) received 1.5-3x106/kg MSC on post-operative day 3±2. These patients were prospectively compared to a group of 10 control (MSC-) liver recipients. Primary endpoints were MSC infusion toxicity, and incidence of cancer and opportunistic infections at month 6. Secondary endpoints were patient and graft survivals and rejection at month 6, as well as the effects of MSC on recipients’ immune function and on immunohistology of at month 6 graft biopsies. Results: No MSC infusional toxicity was observed. Both groups were comparable in terms of donor and recipient characteristics. There was no difference in primary end-points between control and MSC groups. No patient developed de novo cancer. There was no statistical difference in patient and graft survivals or in rejection rates. There was no graft rejection in the MSC group. Month-6 graft biopsies were not different according to Banff and fibrosis scores. Discussion: This phase 1 study showed excellent tolerability and safety of a single infusion of third-party MSC after liver transplantation. There were no graft safety issues and no excess of immunosuppression after MSC injection. Further analyses of consequences of MSC injection on the immune profile are needed. The possibility of avoiding calcineurin-inhibitors with repeated MSC injections as main immunosuppressive therapy and/of tolerance induction by MSC infusion should be investigated by further studies

Infusion of third-party mesenchymal stromal cells after liver transplantation: a phase 1, open-label, clinical study

Background: Mesenchymal stromal cells (MSC) are multipotent bone mar- row progenitors that have demonstrated significant immunosuppressive effects in various in vivo and in vitro studies. This study aimed to be the first evaluation of the safety and tolerability of MSC infusion after liver transplantation in a prospective, controlled phase-1 study. Methods: 10 liver transplant recipients under standard immunosuppression (TAC-MMF-low dose steroids until day 30) received 1.5–3 9 106/kg third party MSC on post-operative day 3 ` 2. These patients were prospectively compared to a group of 10 control liver recipients. Primary endpoints were MSC infusion toxicity, and incidence of cancer and opportunistic infections at month 6. Secondary endpoints were patient and graft survivals and rejection at month 6, as well as the effects of MSC on recipients’ immune function and on immunohistology of at month 6 graft biopsies. Results: No MSC infusional toxicity was observed. Both groups were comparable in terms of donor and recipient characteristics. There was no difference in primary end-points between control and MSC groups. No patient developed de novo cancer. There was no statistical difference in patient and graft survivals or in rejection rates. There was no graft rejection in the MSC group. Month-6 graft biopsies were not different according to Banff and fibrosis scores. Discussion: This phase 1 study showed excellent tolerability and safety of a single infusion of third-party MSC after liver transplantation. There were no graft safety issues and no excess of immunosuppression after MSC injection. Further analyses of consequences of MSC injection on the immune profile are needed. The possibility of avoiding calcineurin-inhibitors with repeated MSC injections as main immunosuppressive therapy and/of tolerance induction by MSC infusion should be investigated by further studies. This study is in part supported by an ESOT Senior Clinical Research Grant and by the University of Liege

Prognostic value of (18)F-FDG PET/CT in liver transplantation for hepatocarcinoma.

AIM: To evaluate the prognostic value of pretreatment FDG positron emission tomography computed tomography (PET-CT) in patients with hepatocarcinoma treated by liver transplantation (LT). METHODS: The authors retrospectively analyzed the data of 27 patients (mean age 58 +/- 9 years) who underwent FDG PET-CT before LT for hepatocarcinoma. Mean follow-up was 26 +/- 18 mo. The FDG PET/CT was performed according to a standard clinical protocol: 4 MBqFDG/kg body weight, uptake 60 min, low-dose non-enhanced CT. The authors measured the SUVmax and SUVmean of the tumor and the normal liver. The tumor/liver activity ratios (RSUVmax and RSUVmean) were tested as prognostic factors and compared to the following conventional prognostic factors: MILAN, CLIP, OKUDA, TNM stage, alphafoetoprotein level, portal thrombosis, size of the largest nodule, tumor differentiation, microvascular invasion, underlying cirrhosis and liver function. RESULTS: Overall and recurrence free survivals were 80.7% and 67.4% at 3 years, and 70.6% and 67.4% at 5 years, respectively. According to a multivariate Cox model, only FDG PET/CT RSUVmax predicted recurrence free survival. Even though the MILAN criteria alone were not predictive, it is worth noting that none of the patients outside the MILAN criteria and with RSUVmax < 1.15 relapsed. CONCLUSION: FDG PET/CT with an RSUVmax cut-off value of 1.15 is a strong prognostic factor for recurrence and death in patients with HCC treated by LT in this retrospective series. Further prospective studies should test whether this metabolic index should be systematically included in the preoperative assessment

The prognostic value of preoperative FDG PET-CT in hepatocellular carcinoma treated by liver transplantation.

peer reviewe

Prognostic value of (18)F-FDG PET/CT in liver transplantation for hepatocarcinoma.

AIM: To evaluate the prognostic value of pretreatment FDG positron emission tomography computed tomography (PET-CT) in patients with hepatocarcinoma treated by liver transplantation (LT). METHODS: The authors retrospectively analyzed the data of 27 patients (mean age 58 +/- 9 years) who underwent FDG PET-CT before LT for hepatocarcinoma. Mean follow-up was 26 +/- 18 mo. The FDG PET/CT was performed according to a standard clinical protocol: 4 MBqFDG/kg body weight, uptake 60 min, low-dose non-enhanced CT. The authors measured the SUVmax and SUVmean of the tumor and the normal liver. The tumor/liver activity ratios (RSUVmax and RSUVmean) were tested as prognostic factors and compared to the following conventional prognostic factors: MILAN, CLIP, OKUDA, TNM stage, alphafoetoprotein level, portal thrombosis, size of the largest nodule, tumor differentiation, microvascular invasion, underlying cirrhosis and liver function. RESULTS: Overall and recurrence free survivals were 80.7% and 67.4% at 3 years, and 70.6% and 67.4% at 5 years, respectively. According to a multivariate Cox model, only FDG PET/CT RSUVmax predicted recurrence free survival. Even though the MILAN criteria alone were not predictive, it is worth noting that none of the patients outside the MILAN criteria and with RSUVmax < 1.15 relapsed. CONCLUSION: FDG PET/CT with an RSUVmax cut-off value of 1.15 is a strong prognostic factor for recurrence and death in patients with HCC treated by LT in this retrospective series. Further prospective studies should test whether this metabolic index should be systematically included in the preoperative assessment