La prise en charge des infections virales survenant dans des contextes d’immunodépression variés constitue un véritable défi. Les médicaments antiviraux présentent en effet une efficacité inconstante avec l’apparition de résistance, mais sont aussi pourvoyeurs de toxicité conduisant à la contre-indication de leur administration. Restaurer une fonction immunitaire spécifique chez les patients constitue une approche séduisante qui peut permettre d’obtenir une efficacité antivirale durable. Les thérapies cellulaires se développent depuis près de trente ans et l’une d’entre elles, l’EBVALLO dirigée contre l’EBV, est un médicament de thérapie innovante avec autorisation de mise sur le marché. Dans cette revue, nous proposons de présenter les lymphocytes T antiviraux pour lesquels une expérience clinique importante est relatée dans la littérature. Nous nous intéresserons également à d’autres types de thérapies cellulaires au stade de développement préclinique, tels que les progéniteurs T ou les lymphocytes T γδ pour lesquels la preuve de concept dans les infections virales reste à faire.

Purpose:Medulloblastoma (MB) is the most prevalent paediatric brain tumour. Despite improvements in patient survival with current treatment strategies, the quality of life of these patients remains poor owing to the sequelae and relapse risk. An alternative, or, in addition to the current standard treatment, could be considered immunotherapy, such as Natural Killer cells (NK). NK cells are cytotoxic innate lymphoid cells that play a major role in cancer immunosurveillance. To date, the mechanism of cytotoxicity of NK cells, especially regarding the steps of adhesion, conjugation, cytotoxic granule polarisation in the cell contact area, perforin and granzyme release in two and three dimensions, and therapeutic efficacy in vivo have not been precisely described. Materials and Methods:Each step of NK cytotoxicity against the three MB cell lines was explored using confocal microscopy for conjugation, Elispot for degranulation, flow cytometry, and luminescence assays for target cell necrosis and lysis and mediators released by cytokine array, and then confirmed in a 3D spheroid model. Medulloblastoma-xenografted mice were treated with NK cells. Their persistence was evaluated by flow cytometry, and their efficacy in tumour growth and survival was determined. In addition, their effects on the tumour transcriptome were evaluated. Results:NK cells showed variable affinities for conjugation with MB target cells depending on their subgroup and cytokine activation. Chemokines secreted during NK and MB cell co-culture are mainly associated with angiogenesis and immune cell recruitment. NK cell cytotoxicity induces MB cell death in both 2D and 3D co-culture models. NK cells initiated an inflammatory response in a human MB murine model by modulating the MB cell transcriptome. Conclusion:Our study confirmed that NK cells possess both in vitro and in vivo cytotoxic activity against MB cells and are of interest for the development of immunotherapy.

In 2020, 18,796 allo-stem cell transplants (SCT) were performed in European countries1 and approximately 2000 in France alone.2 Although the toxicity-related mortality (TRM) had decreased, infections remained a significant cause of TRM.3, 4 Of note, the current use of either ex vivo or in vivo T-cell depletion prevents alloreactivity (graft rejection and graft-versus-host disease [GVHD]) but enables viral infections/reactivations due to a delayed immune reconstitution. The incidence and severity of viral infections/reactivations has decreased thanks to the implementation of pre-emptive antiviral chemotherapies, but they still represent a life-threatening complication of allo-SCT.5 Indeed, a relevant number of patients still experience therapy-refractory infections in the absence of concomitant immune reconstitution.6-8 A recent observational study reported that in the first 100 days posttransplant, the cumulative incidence of death caused by infections is 2.3% (0.25% from viral origin).4 Antiviral therapies are associated with consistent side effects such as acute kidney injury or hematotoxicity that might worsen the overall prognosis.6-9 For adenovirus (AdV),10-12 cytomegalovirus (CMV),13, 14 and Epstein Barr virus (EBV), virus-specific T-cells (VST) have been developed as an alternate therapy,15, 16 since the pioneering work of Pr Riddell et al. in 1992 and international colleagues afterward.17-22 Since 2016, France approved AdV-VST, EBV-VST, or CMV-VST production in the Cell Therapy Unit of the University Hospital of Nancy (UTCT) as Advanced Therapy Medicinal Products (ATMP). Twenty-nine consecutive patients with AdV, EBV, or CMV replications/infections, persisting despite an optimized antiviral therapy, were infused. We retrospectively analyzed the data in terms of safety and efficacy, considering VST were in more than half cases prepared from third-party haploidentical donors. The protocol was approved by the French Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) research committee and was conducted in accordance with the Declaration of Helsinki and the Good Clinical Practice Guideline of the International Conference on Harmonisation. All patients provided written informed consent, including legal guardians for patients under 18 years old. Eligible patients were defined as: (1) allo-SCT patients (2) with viral replication and/or tissue infection with CMV, AdV, or EBV refractory to standard therapy; (3) standard therapy was defined by at least 14 days of full-treatment dose of ganciclovir or foscarnet or cidofovir for CMV, or cidofovir or brincidofovir for AdV (off-label use) and stable disease (SD) or progressive disease (PD) observed under weekly perfusion of rituximab for EBV replication, or SD or PD observed under cytotoxic chemotherapy with or without rituximab for EBV-related posttransplant lymphoproliferative disorder (PTLD). Patients were considered ineligible when they presented uncontrolled aGVHD > grade II23 or uncontrolled chronic GVHD > NIH 2.24 All immunosuppressive drugs were allowed and corticosteroids were <1 mg/kg/day in most cases. UTCT of Nancy is the only laboratory in France authorized by the French regulatory agency Agence Nationale de Sécurité du Médicament (ANSM) to produce AdV-specific T-cells as an ATMP under hospital exemption (MTI-PP-009) and to deliver EBV-VST or CMV-VST for compassionate use after nominative ANSM “non opposition” with a prospective monitoring requirement. The definition of replication or disease followed the guidelines of the SFGM-TC. Conditioning regimens were divided into myeloablative (MAC), reduced-intensity conditioning (RIC), and nonmyeloablative (NMA) as the established definitions by Bacigalupo et al.,25 applicable to both adult and pediatric patients. Serious adverse events (SAE) were defined according to the Common Terminology Criteria for Adverse Events (CTCAE version 5.0). Complete response (CR) was defined as complete clearance of the virus, and partial response (PR) was defined as a viral load decrease ≥1 log. The immune reconstitution monitoring was assessed by each center using an IFN-γ-positive ELIspot assay or a proliferative test when the technique was locally available. The SFGM-TC group received eighty referral procedures: fifty obtained a favorable opinion, and finally, twenty-nine consecutive patients were infused in 13 different centers (Supporting Information: Figure 1). In the entire cohort, the median follow-up was 74 days (from 8 to 555 days) (see Table 1). Seventeen children (<18 years old) and 12 adults (≥18 years old) were treated. Of note, five patients received two infusions (four patients against CMV and one patient against AdV) and one patient received one VST infusion prepared against both AdV and CMV. Briefly, 51.7% were transplanted for primary immunodeficiency or nonmalignant hematological diseases, and the majority of patients (n = 28) received an in vivo T-cell depletion; the median time between allo-SCT and the viral replication was 46 days (range: 0–1372 days). Infused VST were mainly derived from a related intrafamilial third-party donor (n = 16, 55.2%). Patients were heavily pretreated with a median time of 50 days (range: 21–300 days) of antiviral therapy before the initial VST infusion. VST were produced from leukapheresis obtained from the graft donor for 13 patients (44.8%) and from third-party haplo-identical relatives in 16 patients (55.2%), according to interferon gamma (IFN-γ) immunomagnetic isolation, as previously described by Qian et al.26 The mean dose of CD3+ IFN-γ+ T-cells administered to the patient was 0.82 × 104 ± 0.89 × 104 T-cells/kg with a mean enrichment of 72% of CD4+ IFN-γ+ T-cells (SD: ±17%) and 80% of CD8+ IFN-γ+ T-cells (SD: ±16%). VST were released according to flow cytometry control results. The absence of microbiologic contamination was confirmed after 10 days, except for one production positive for Cutibacterium acnes. Functional and proliferative assays performed a few weeks after infusion demonstrated a low alloreactivity and a high cytotoxicity against specific virus. Within 3 months post-VST infusion, there was no de novo aGVHD. Unfortunately, two patients experienced a recurrent grade III–IV aGVHD. Patients 3 and 12 developed recurrent aGVHD attributed to rapid corticosteroid taper (patient 3 had a recurrence at D38 from the day of VST infusion (D0) when corticosteroids were lower than 0.3 mg/kg/day, and patient 12 had a recurrence at D27, 10 days after corticosteroid discontinuation). One patient developed a de novo pulmonary cGVHD at D45. Of note, all the patients infused with VST were considered in remission or at least with controlled GVHD at the time of infusion. The first cause of death within the 3 months post-VST was the initial virus-related replication/disease (n = 9) followed by TRM (n = 3), one from severe progressive grade III (hepatic aGVHD), one from hepatic failure secondary to hepatorenal syndrome with refractory ascites, and one from pulmonary alveolar hemorrhage. After 3 months, the causes of death were allo-SCT TRM (n = 5). Overall response rate (ORR) at 1-month postinfusion was 56%. The ORR at 3 months was 62%. At 3 months, six patients were still nonresponders: four of them had advanced viral disease at D0 and died (patients 2, 3, 7, and 13) and two maintained a stable viral load (patients 20 and 24). Patient 10 died at D78 after achieving PR at D30 and CR at D75 (Figure 1A). Patients who received an AdV-VST infusion were significantly better responders than those who received CMV-VST and EBV-VST (p < 0.01) (Figure 1B). There was no significant difference in ORR between an HLA-matched original graft donor versus a third-party haploidentical donor (p = 0.415) (Figure 1C). Finally, the median time to the best virological response (CR) was 18 days (range: 10–75 days). In the entire cohort, OS post-VST-infusion was 56% and 29% at 3 and 12 months postinfusion, respectively (Figure 1D). Interestingly, OS was significantly higher when the viral load at infusion was <5 log (p < 0.001), regardless of the implicated virus (Figure 1E). We performed univariate analysis to assess the following possible risk factors for response, and these are our findings. The ORR was not significantly different according to the following immunological parameters: the previous in vivo T-cell depletion (ATG vs. alemtuzumab vs. PTCy, p = 1.000), the continuation of corticosteroids at a dose <1 mg/kg/day at the time of VST transfer (n = 12) (p = 0.677), and adapted immunosuppression (n = 8) or not (n = 21) (p = 0.626) (see Supporting Information: Tables 1 and 2). Immune reconstitution was investigated in 11 patients, with 7 of them experiencing specific immune reconstitution assessed by proliferative assay or ELIspot IFN-γ assay. Among patients treated with corticosteroids at the time of VST infusion, immune reconstitution was documented for patients 3, 5, 11, 14, and 22, and 4 out of these 5 patients cleared the virus (see Supporting Information: Figures 1 and 2). In conclusion, this is a real-life study reporting a cohort of 29 patients treated with VST. It is also the largest cohort of patients receiving VST generated by IFN-γ immunomagnetic isolation from a haploidentical related donor different from the allo-SCT donor. We report encouraging results but also highlight the fact that results were probably impaired due to the significant delay between infection and VST infusion. The authors warmly thank all the technical staff of the cell therapy unit from the Nancy University Hospital for VST production, including Jessica Morello and Mathilde Ollinger, for performing functional quality controls. They also thank all the technical staff of the Cytometry Platform of the Nancy University Hospital. Finally, they thank the MTI-PP group (Dr. Karin Bilger, Dr. Laurence Clément, Pr. Jean-Hugues Dalle, Pr. Véronique Decot, Dr. Jérôme Larghero, Dr. Anne Legendre, Dr. Nadine Petitpain, Dr. Cécile Pochon, and Dr. Hélène Rouard). Esther Hazane Leroyer, Nadine Petitpain, Maud D'Aveni, and Danièle Bensoussan collected all data. Esther Hazane Leroyer, Maud D'Aveni, and Danièle Bensoussan wrote the main manuscript text. Esther Hazane Leroyer prepared all figures and Maud D'Aveni and Danièle Bensoussan reviewed them. Sébastien Maury performed statistical analysis. All authors reviewed the manuscript. Maud D'Aveni and Danièle Bensoussan contributed equally to the work. The authors declare no conflict of interest. This research received no funding. The data that support the findings of this study are available from the corresponding author upon reasonable request. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Background aims: Allogeneic hematopoietic stem cell transplantation (allo-SCT) is a curative treatment for chemo-resistant hematological malignancies. Because of transport restriction imposed by the coronavirus disease 2019 pandemic, regulatory bodies and societies recommended graft cryopreservation before recipi-ent conditioning. However, the freezing and thawing processes, including washing steps, might impair CD34 + cell recovery and viability, thereby impacting the recipient engraftment. Over 1 year (between March 2020 and May 2021), we aimed to analyze the results of frozen/thawed peripheral blood stem cell allografts in terms of stem cell quality and clinical outcomes.Methods: Transplant quality was evaluated by comparing total nucleated cells (TNCs), CD34+ cells and col-ony-forming unit-granulocyte/macrophage (CFU-GM)/kg numbers as well as TNC and CD34+ cell viabilities before and after thawing. Intrinsic biological parameters such as granulocyte, platelet and CD34+ cell concen-trations were analyzed, as they might be responsible for a quality loss. The impact of the CD34+ cell richness of the graft on TNC and CD34 yields was evaluated by designing three groups of transplants based on their CD34 /kg value at collection: >8 x 10 6/kg, between 6 and 8 x 106/kg and <6 x 106/kg. The consequences of cryopreservation were compared in the fresh and thawed group by evaluating the main transplant outcomes.Results: Over 1 year, 76 recipients were included in the study; 57 patients received a thawed and 19 patients a fresh allo-SCT. None received allo-SCT from a severe acute respiratory syndrome coronavirus 2-positive donor. The freezing of 57 transplants led to the storage of 309 bags, for a mean storage time (between freez-ing and thawing) of 14 days. For the fresh transplant group, only 41 bags were stored for potential future donor lymphocyte infusions. Regarding the graft characteristics at collection, median number of cryopre-served TNC and CD34+ cells/kg were greater than those for fresh infusions. After thawing, median yields were 74.0%, 69.0% and 48.0% for TNC, CD34+ cells and CFU-GM, respectively. The median TNC dose/kg obtained after thawing was 5.8 x 108, with a median viability of 76%. The median CD34+ cells/kg was 5 x 106, with a median viability of 87%. In the fresh transplant group, the median TNC/kg was 5.9 x 108/kg, and the median CD34+ cells/kg and CFU-GM/kg were 6 x 106/kg and 276.5 x 104/kg, respectively. Sixty-one percent of the thawed transplants were out of specifications regarding the CD34+ cells/ kg requested cell dose (6 x 106/kg) and 85% of them would have had this dose if their hematopoietic stem cell transplant had been infused fresh. Regarding fresh grafts, 15.8% contained less than 6 x 106 CD34+ cells /kg and came from peripheral blood stem cells that did not reach 6 x 106 CD34+ cells /kg at collection. Regarding the factor that impaired CD34 and TNC yield after thawing, no significant impact of the granulocyte count, the platelet count or the CD34+ cells concentration/mL was observed. However, grafts containing more than 8 x 10 6/kg at col-lection showed a significantly lower TNC and CD34 yield.Conclusions: Transplant outcomes (engraftment, graft-versus-host disease, infections, relapse or death) were not significantly different between the two groups.& COPY; 2023 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.

The development of Chimeric Antigen Receptor T cells therapy initiated by the United States and China is still currently led by these two countries with a high number of clinical trials, with Europe lagging in launching its first trials. In this systematic review, we wanted to establish an overview of the production of CAR-T cells in clinical trials around the world, and to understand the causes of this delay in Europe. We particularly focused on the academic centers that are at the heart of research and development of this therapy. We counted 1087 CAR-T cells clinical trials on ClinicalTrials.gov (Research registry ID: reviewregistry1542) on the date of 25 January 2023. We performed a global analysis, before analyzing the 58 European trials, 34 of which sponsored by academic centers. Collaboration between an academic and an industrial player seems to be necessary for the successful development and application for marketing authorization of a CAR-T cell, and this collaboration is still cruelly lacking in European trials, unlike in the leading countries. Europe, still far behind the two leading countries, is trying to establish measures to lighten the regulations surrounding ATMPs and to encourage, through the addition of fundings, clinical trials involving these treatments.

Background The COVID-19 pandemic caused a wave of acute respiratory distress syndrome (ARDS) with a high in-hospital mortality, especially in patients requiring invasive mechanical ventilation. Wharton Jelly-derived Mesenchymal Stromal Cells (WJ-MSCs) may counteract the pulmonary damage induced by the SARS-CoV-2 infection through pro-angiogenic effects, lung epithelial cell protection, and immunomodulation. Methods In this randomized, double-blind, placebo-controlled phase 2a trial, adult patients receiving invasive mechanical ventilation for SARS-CoV-2 induced moderate or severe ARDS were assigned to receive 1 intravenous infusion of 1 × 106 WJ-MSCs/kg or placebo within 48 h of invasive ventilation followed by 2 infusions of 0.5 × 106 WJ-MSCs/kg or placebo over 5 days. The primary endpoint was the percentage of patients with a PaO2/FiO2 > 200 on day 10. Results Thirty patients were included from November 2020 to May 2021, 15 in the WJ-MSC group and 15 in the placebo group. We did not find any significant difference in the PaO2/FiO2 ratio at day 10, with 18 and 15% of WJ-MSCs and placebo-treated patients reaching a ratio >200, respectively. Survival did not differ in the 2 groups with a 20% mortality rate at day 90. While we observed a higher number of ventilation-free days at 28 days in the WJ-MSC arm, this difference was not statistically significant (median of 11 (0–22) vs. 0 (0–18), p = 0.2). The infusions were well tolerated, with a low incidence of anti-HLA alloimmunization after 90 days. Conclusion While treatment with WJ-MSCs appeared safe and feasible in patients with SARS-CoV2 moderate or severe ARDS in this phase 2a trial, the treatment was not associated with an increased percentage of patients with P/F > 200 at 10d, nor did 90 day mortality improve in the treated group. Clinical trial registration https://beta.clinicaltrials.gov/study/NCT04625738, identifier NCT04625738.

BACKGROUND:Many clinical trials have reported the use of mesenchymal stromal cells (MSCs) following the indication of severe SARS-CoV-2 infection. However, in the COVID19 pandemic context, academic laboratories had to adapt a production process to obtain MSCs in a very short time. Production processes, especially freezing/thawing cycles, or culture medium have impacts on MSC properties. We evaluated the impact of an intermediate cryopreservation state during MSC culture to increase production yields.METHODS:Seven Wharton's jelly (WJ)-MSC batches generated from seven different umbilical cords with only one cryopreservation step and 13 WJ-MSC batches produced with intermediate freezing were formed according to good manufacturing practices. The identity (phenotype and clonogenic capacities), safety (karyotype, telomerase activity, sterility, and donor qualification), and functionality (viability, mixed lymphocyte reaction) were analyzed.RESULTS:No significant differences between MSC production processes were observed, except for the clonogenic capacity, which was decreased, although it always remained above our specifications.CONCLUSIONS:Intermediate cryopreservation allows an increase in the production yield and has little impact on the basic characteristics of MSCs.

Monoclonal antibodies targeting tumors are one of the most important discoveries in the field of cancer. Although several effective antibodies have been developed, a relapse may occur. One of their mechanisms of action is Antibody Dependent Cell Cytotoxicity (ADCC), by engaging the Fc γ receptor CD16 expressing Natural Killer cells, innate lymphoid cells involved in cancer immunosurveillance and able to kill tumor cells. A lack of NK cells observed in many cancers may therefore be a cause of the low efficacy of antibodies observed in some clinical situations. Here we review clear evidences of the essential partnership between NK cells and antibodies showed in vitro, in vivo, and in clinical trials in different indications, describe the hurdles and ways to enhance ADCC and the evolution of monoclonal antibody therapy. NK cell adoptive immunotherapy combined with monoclonal antibodies may overcome the resistance to the treatment and enhance their efficacy.

Viral infections are major complications of Hematopoietic Stem Cell Transplantation (HSCT). As efficacy of anti-viral drugs is limited in absence of immune reconstitution and often associated with severe side effects, infusion of Virus-Specific T cells (VSTs) becomes a promising alternative treatment for viral infections and diseases after HSCT. A lot of improvement in VST generation has been made since 1992, date of first attempts. Regarding stimulation antigen, pools of peptides from viral immunodominant proteins become the best choice compared to whole proteins or other types of antigens. In respect with generation methods, a huge improvement has been done both with cell culture thanks to faster protocols of expansion and with immunomagnetic isolation thanks to fully automated generation of VSTs with a close system. This latest kind of VST generation is fast (within 24 hours), compliant with GMP guidelines and allows a wide distribution among cell therapy laboratories. Furthermore, cell source is no longer limited to the HSCT donor. Third-party donors either related or unrelated are also sought. A promising perspective could be the generation of CART based on VSTs aiming both at targeting the malignant cells and controlling the viral infections simultaneously.

Many clinical trials report mesenchymal stem/stromal cells (MSCs) efficacy in various indications. Therefore, standardization of MSC production becomes necessary. MSC properties are impacted by tissue origin, especially if they are from extraembryonic tissue or adult sources. For this reason, we evaluated the impact of MSC tissue origin on production. Methods: Three productions of MSC from Wharton's Jelly (WJ) or from bone marrow (BM) were performed according to good manufacturing practice. The identity (phenotype, differentiation, and clonogenic capacities), safety (karyotype, telomerase activity, sterility, and donor qualification), and functionality (viability, mixed lymphocyte reaction) of each cell batch were analyzed. Results: Slight differences between MSC sources were observed for phenotype, telomerase activity, and clonogenic capacities. Conclusion: Both sources have made it possible to quickly and easily obtain clinical grade MSC. However, as availability of the source is thought to be essential, WJ seems more advantageous than BM.

Le succès aussi extraordinaire qu’inattendu de l’immunothérapie cellulaire utilisant des lymphocytes T génétiquement modifiés pour exprimer un récepteur chimérique à l’antigène (CAR) ciblant CD19, dans le traitement de certaines hémopathies B réfractaires ou en rechute, a permis un véritable espoir. Les taux de rémission atteignent plus de 80 % chez des patients pédiatriques en impasse thérapeutique. Ces travaux initialement issus de la recherche académique ont conduit à l’autorisation de mise sur le marché de deux médicaments de thérapie innovante (MTI) autologues, Kimryah® et Yescarta®. Les résultats cliniques impressionnants, certes principalement dans les hémopathies malignes, laissent entrevoir des applications très diverses notamment pour les tumeurs solides. Cependant, si le développement des cellules CAR-T semble aujourd’hui aux mains des industriels, les contraintes logistiques, la cryopréservation et le coût très important, risque à terme de limiter leur usage. Le développement de productions académiques de cellules CAR-T pourrait contourner ces inconvénients. L’innovation des établissements de santé associés à des unités de recherche permet d’identifier la cible tumorale idéale, les cellules effectrices performantes, et de disposer de plateformes de production autorisées permettant un délai d’administration raccourci avec un coût de production acceptable pour les systèmes de santé. Cet atelier permet de recenser les prérequis nécessaires à une production académique des CAR-T cells, en respectant les standards de la recherche nécessaire à la preuve de concept, et à l’étape de développement préclinique, conduisant à la fabrication, in fine, par un établissement pharmaceutique autorisé, du MTI. Le but ultime est de permettre l’accessibilité de ces MTI au plus grand nombre de patients.

The extraordinary and unexpected success of cellular immunotherapy using genetically engineered T-cells to express a chimeric antigen receptor (CAR) targeting CD19, in the treatment of refractory or relapsing 8-hematological malignancies, has provided a real therapeutic hope. Indeed, remission rotes reach more than 80 % in patients at a stage, without any other possibilities of treatment, notably in the child's acute lymphoblastic leukemia. These results, initially resulting from academic research, led to Food and Drug accreditation for market access of two innovative autologous therapy drugs, Kimryah (R) and Yescarta (R). Based on the impressive clinical results, mainly so for in hematological malignancies (LAL, MM, LBDGC, etc.), the development of several types of cells expressing a CAR receptor suggests a wide range of future applications, particularly in the field of solid tumors. However, while the development of CAR-T cells now appears to be in the hands of private pharmaceuticals companies, the logistical constraints, the cryopreservation and the very high cost of these personalized medicines may ultimately limit their use. The development of academic productions by CAR-T cells could bypass some of these disadvantages. The strong innovation capacity of healthcare institutions associated with research units allows them to identify the ideal tumor target and efficient performing cells. Thus, authorized production platforms could allow for shorter administration times and reasonable production costs for national health systems. The aim of this workshop is to identify the requirements for the academic production of CAR-T cells, while respecting the research standards useful to establish proof of concept, but also at the predinical development stage, leading in fine to the manufacture, through an authorized pharmaceutical establishment, of the innovative therapy drug, and in accordance with Good Manufacturing Practice (GMP). The ultimate goal is to make these innovative and high-performance medicines available to as many patients as possible.

Angiogenesis is a critical parameter to consider for the development of tissue-engineered bone substitutes. The challenge is to promote sufficient vascularization in the bone substitute to prevent cell death and to allow its efficient integration. The capacity of nacre extract to restore the osteogenic activity of osteoarthritis osteoblasts has already been demonstrated. However, their angiogenic potential on endothelial progenitor cells (EPCs) was not yet explored. Therefore, the current study aimed at investigating if nacreous molecules affect EPC behavior. The gene and protein expression levels of endothelial cell (EC)-specific markers were determined in EPCs cultivated in presence of a nacre extract (ethanol soluble matrix [ESM] at two concentrations: 100 μg/mL and 200 μg/mL (respectively abbreviated ESM100 and ESM200)). Cell functionality was explored by proangiogenic factors production and in vitro tube formation assay. ESM200 increased the expression of some EC-specific genes. The in vitro tube formation assay demonstrated that ESM200 stimulated tubulogenesis affecting angiogenic parameters. We demonstrated that a stimulation with 200 μg/mL of ESM increased angiogenesis key elements. This in vitro study strongly highlights the proangiogenic effect of ESM. Due to its osteogenic properties, previously demonstrated, ESM could constitute the key element to develop an ideal prevascularized bone substitute. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.