The essential role of interleukin 7 (IL-7) signaling via its receptor (IL-7Rα; CD127) in T cell development and function has been well documented. However, CD127 expression and function in myeloid cells, including monocytes, are less clear, especially in mice. In the present study we report an inducible CD127 expression in mouse monocytes/macrophages. This induction is dependent on the presence of other immune cells, highlighting that regulation of CD127 expression on monocytes differs in mice and humans. We demonstrate that CD127 is functional, as IL-7 downregulated its expression. We also saw decreased CD127 expression during inflammation in vivo. Overall, upregulation of CD127 expression in vitro and its downregulation in vivo confirm that CD127 is an inducible marker on mouse monocyte/macrophage cells, in contrast to findings recently published by others. Characterizing the role of CD127 signaling in myeloid cells in inflammatory disorders would be worthwhile in future study.

GATA-binding factor 1 (GATA1) is a transcription factor that governs the development and function of multiple hematopoietic cell lineages. GATA1 is expressed in hematopoietic stem and progenitor cells (HSPCs) and is essential for erythroid lineage commitment; however, whether it plays a role in hematopoietic stem cell (HSC) biology and the development of myeloid cells, and what that role might be, remains unclear. We initially set out to test the role of eosinophils in experimental autoimmune encephalomyelitis (EAE), a model of central nervous system autoimmunity, using mice lacking a double GATA-site (ΔdblGATA), which lacks eosinophils due to the deletion of the dblGATA enhancer to Gata1, which alters its expression. ΔdblGATA mice were resistant to EAE, but not because of a lack of eosinophils, suggesting that these mice have an additional defect. ΔdblGATA mice with EAE had fewer inflammatory myeloid cells than the control mice, suggesting that resistance to EAE is caused by a defect in myeloid cells. Naïve ΔdblGATA mice also showed reduced frequency of CD11b+ myeloid cells in the blood, indicating a defect in myeloid cell production. Examination of HSPCs revealed fewer HSCs and myeloid cell progenitors in the ΔdblGATA bone marrow (BM), and competitive BM chimera experiments showed a reduced capacity of the ΔdblGATA BM to reconstitute immune cells, suggesting that reduced numbers of ΔdblGATA HSPCs cause a functional deficit during inflammation. Taken together, our data show that GATA1 regulates the number of HSPCs and that reduced GATA1 expression due to dblGATA deletion results in a diminished immune response following the inflammatory challenge.

Background Replacement of carmustine (BCNU) in the BEAM regimen (BCNU, etoposide, cytarabine, melphalan) with bendamustine (BendaEAM) before autologous stem cell transplantation (ASCT) is feasible in lymphoma. However, randomised trials are lacking. Here, we present the first trial addressing this topic.Methods This multicentre, randomised, phase 2 study (BEB-trial) conducted at four haematological centres in Austria and Switzerland compares BEAM with BendaEAM in patients with relapsed lymphoma. Both regimens were administered intravenously before ASCT, in BEAM according to the standard protocol (300 mg/m2 BCNU on day -6), in BendaEAM, BCNU was replaced by 200 mg/m2 bendamustine given on days -7 and -6. Eligible patients were aged 18-75 years and had mantle cell lymphoma, diffuse large B-cell lymphoma, or follicular lymphoma in first or second remission or chemosensitive relapse. The primary endpoint of the study was to evaluate whether replacement of BCNU by bendamustine reduces lung toxicity, defined as a decrease of the diffusion capacity of the lung for carbon monoxide by at least 20% at three months after ASCT. Data analyses were performed on an intention-to-treat basis. This study is registered with ClinicalTrials.gov, number NCT02278796, and is complete.Findings Between April 20, 2015, and November 28, 2018, 108 patients were enrolled; of whom 53 were randomly assigned to receive BendaEAM (36 male, 17 female) and 55 to receive BEAM (39 male, 16 female). All patients engrafted rapidly. Lung toxicity did not differ between groups (BendaEAM: n = 8, 19.5%; BEAM: n = 11, 25.6%; risk difference = -6.1%: 95% confidence interval: -23.9% to 11.7%). Acute toxicities of at least grade 3 were comparable in both groups (BendaEAM: 35.8%, BEAM: 30.9%). Overall survival (BendaEAM: 92.5%, BEAM: 89.1%) and complete remission (BendaEAM: 76.7%, BEAM: 74.3%) after 1 year (median follow-up: 369 days) were similar. No difference in quality of life was observed.Interpretation Results were similar for both regimens in terms of survival and response rates. A phase 3 non -inferiority study is required to investigate whether BendaEAM can be considered as an alternative to BEAM. 2023;66: Published https://doi.org/10. 1016/j.eclinm.2023. 102318

Significance Multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), are autoimmune diseases characterized by accumulation of myeloid cells in the central nervous system (CNS). Both harmful and beneficial myeloid cells are present in EAE/MS, and a goal of MS therapy is to preferentially remove harmful myeloid cells. The receptor for CSF-1 (CSF-1R) is found on myeloid cells and is important for their survival. CSF-1R can bind two ligands, CSF-1 and IL-34, but it is not known whether their functions in EAE/MS differ. We found that blocking CSF-1 depleted only harmful myeloid cells in the CNS and suppressed EAE, whereas blocking IL-34 had no effect. Thus, we propose that blocking CSF-1 could be a therapy for MS.

Abstract PURPOSE: Advances in treatment have increased survival rates and quality of life of pediatric CNS tumor patients leading to a growing number of long-term survivors. However, there is sufficient clinical and scientific evidence for the need of a highly specialized lifelong follow-up care due to multidimensional late effects. Furthermore, adolescence and young adulthood are challenging age periods when patients frequently get lost to follow-up potentially having severe impact on health and well-being. Since 2020, we have established a structured transfer of long-term survivors older than 18 years to a newly founded highly specialized adult care follow-up setting for childhood cancer survivors (IONA). The aim of this study was to evaluate the current transition process. RESEARCH DESIGN: The standard of care transition process at the neuro-oncology unit of the MUV includes a joint appointment with the patient, a pediatric neuro-oncologist, psychologist and/or social worker and the team of the adult care facility (physician, psychologist). Different elements are used to end care safely in the pediatric structure and building trust in the upcoming out-patient-department at the same time. The transition process was evaluated statistically and analyzed qualitatively with regard to the factors that define a safe transition. RESULTS: After two years (01/2020-12/2021) 114 patients had a joint transition appointment, two patients contacted IONA directly. Shortly after the joint appointment all patients had a scheduled follow-up meeting at IONA. 102 patients (87.9%) showed up, seven patients (6%) already had a planned appointment, two patients (1.7%) were in contact with IONA but had no possibility to show up in person. Only five patients (4.3%) did not attend the appointment and were lost to follow-up. CONCLUSION: A structured interdisciplinary transition concept is a successful option to establish controlled and patient-safe transition from pediatric to adult care setting.

Astrocytes are highly heterogeneous in their phenotype and function, which contributes to CNS disease, repair, and aging; however, the molecular mechanism of their functional states remains largely unknown. Here, we show that activation of sirtuin 1 (SIRT1), a protein deacetylase, played an important role in the detrimental actions of reactive astrocytes, whereas its inactivation conferred these cells with antiinflammatory functions that inhibited the production of proinflammatory mediators by myeloid cells and microglia and promoted the differentiation of oligodendrocyte progenitor cells. Mice with astrocyte-specific Sirt1 knockout (Sirt1–/–) had suppressed progression of experimental autoimmune encephalomyelitis (EAE), an animal model of CNS inflammatory demyelinating disease. Ongoing EAE was also suppressed when Sirt1 expression in astrocytes was diminished by a CRISPR/Cas vector, resulting in reduced demyelination, decreased numbers of T cells, and an increased rate of IL-10–producing macrophages and microglia in the CNS, whereas the peripheral immune response remained unaffected. Mechanistically, Sirt1–/– astrocytes expressed a range of nuclear factor erythroid–derived 2–like 2 (Nfe2l2) target genes, and Nfe2l2 deficiency shifted the beneficial action of Sirt1–/– astrocytes to a detrimental one. These findings identify an approach for switching the functional state of reactive astrocytes that will facilitate the development of astrocyte-targeting therapies for inflammatory neurodegenerative diseases such as multiple sclerosis.

Introduction BCNU containing BEAM (BCNU, etoposide, cytarabine, melphalan) is one of the most commonly used conditioning regimens in lymphoma patients before autologous stem cell transplantation (ASCT). A frequently observed non-hematological complication of high-dose BCNU containing regimens is pulmonary toxicity that might lead to permanent damage with a reported incidence varying from 2% to 64%. Replacing BCNU with bendamustine in the BeEAM regimen has shown to be effective and feasible in phase II trials. So far, no randomized clinical trial has compared the established BEAM protocol with the BeEAM regimen. Here we present the results of a randomized phase II clinical trial (EudraCT2014-003629-16). Methods In this multicentre Austrian Swiss trial, 108 patients were enrolled from January 2015 to December 2018 and randomly assigned to the BeEAM (N=53) or BEAM (N=55) arm as a conditioning regimen. Patients enrolled had either mantle cell lymphoma (MCL) (N=39), diffuse large B-cell lymphoma (DLBCL) (N=57) or follicular lymphoma (FL) (N=12). The conditioning regimen was administered according to the standard BEAM protocol (BCNU: 300mg/m2) and the BeEAM regimen was given according the regimen first published by Giuseppe Visani et al. 2011 (bendamustine: 2x200mg/m2 on consecutive days). Hematological engraftment after ASCT was defined as the first day of neutrophil counts above 0.5 x 109/l, and of platelet counts above 20 x 109/l in the absence of platelet transfusion in the previous 3 days. The primary endpoint of the study was to evaluate whether replacement of BCNU by bendamustine could reduce lung toxicity defined, as a decrease of the diffusion capacity of the lung for carbon monoxide (DLCO) by at least 20%, at 3 months after ASCT. Secondary endpoints included overall survival (OS) and progression-free survival (PFS), acute toxicity, hematological recovery and engraftment, pulmonary function parameters as assessed by spiro- and ergometry from diagnosis until 1-year after ASCT and quality of life according to the EORTC-Q30 questionnaire. ResultsAge, disease status and remission status were well balanced and did not differ between the two study groups. Engraftment: Median number of infused CD34+ cells x 106/kg was 4.3 in the BeEAM vs. 4.6 in the BEAM arm. All patients engrafted and there was no difference in time to engraftment between the BeEAM and BEAM group. Respiratory function: The primary endpoint was achieved in 8/41(19.5%) in the BeEAM and in 9/43 (20.9%) in the BEAM group. There was no significant difference in DLCO and spiro- and ergometry in the BeEAM and BEAM group during the whole study period (Table 1). Although 2 patients died because of treatment related lung toxicity in the BEAM arm, we did not observe any functional detoriation in the patients who received the BCNU-containing BEAM regimen. Additionally, blood gas analysis revealed similar results in both study arms at screening, 3 months and 1-year after ASCT. Toxicity: Acute toxicity grade 3-5 according to CTCAE v4.0 was observed in 43.4% of the patients in the BeEAM arm and in 34.5% of the patients in the BEAM arm in the category any adverse event (p =0.43). Infections and infestations were observed in 9.4% of patients in the BeEAM arm and in 14.5% in the BEAM arm (p=0.56). Respiratory, thoracic and mediastinal disorders were only detected in the BEAM arm (5.5%) (p=0.24). In contrast to previous trials, grade 3-5 renal toxicity was low, both in the BeEAM and BEAM arm, respectively (1.9% vs. 1.8%) (p=1.00). Gastrointestinal toxicity occurred more frequently in the BeEAM arm (13.2%) than in the BEAM arm (5.5%) (p=0.20). Median follow-up was 369 days (15-540 days). In the BeEAM arm 4 out of 53 patients died during the observational period, 6 out of 55 in the BEAM arm (log-rank test p=0.54, Figure 1). Ten patients in each group had a progression or died during the observational period (log-rank test p=0.89). Quality of life: There was no statistical difference in the assessment of quality of life in the two study arms. Conclusion BeEAM is a feasible, well tolerated regimen resulting in similar clinical results as observed with the BEAM regimen. Interestingly we did not see any difference in impairment of pulmonary function, however 2 patients died in the BEAM arm of lung toxicity and no lung related deaths were observed in the BeEAM group. In our conclusion, BeEAM is a reasonable alternative to the BEAM regimen. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

D-mannose (D-m) is a glucose epimer found in natural products, especially fruits. In mouse models of diabetes and airway inflammation, D-m supplementation via drinking water attenuated pathology by modifying cellular energy metabolism, leading to the activation of latent transforming growth factor beta (TGF-β), which in turn induced T regulatory cells (Tregs). Given that Tregs are important in controlling neuroinflammation in experimental autoimmune encephalomyelitis (EAE) and likely in multiple sclerosis (MS), we hypothesized that D-m could also suppress EAE. We found that D-m delayed disease onset and reduced disease severity in two models of EAE. Importantly, D-m treatment prevented relapses in a relapsing-remitting model of EAE, which mimics the most common clinical manifestation of MS. EAE suppression was accompanied by increased frequency of CD4+FoxP3+ Tregs in the central nervous system, suggesting that EAE suppression resulted from Treg cell induction by D-m. These findings suggest that D-m has the potential to be a safe and low-cost complementary therapy for MS.

IFN-β has been the treatment for multiple sclerosis (MS) for almost three decades, but understanding the mechanisms underlying its beneficial effects remains incomplete. We have shown that MS patients have increased numbers of GM-CSF+Th cells in circulation, and that IFN-β therapy reduces their numbers. GM-CSF expression by myelin-specific Th cells is essential for the development of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. These findings suggested that IFN-β therapy may functionviasuppression of GM-CSF production by Th cells. In the current study, we elucidated a feedback loop between monocytes and Th cells that amplifies autoimmune neuroinflammation, and found that IFN-β therapy ameliorates central nervous system (CNS) autoimmunity by inhibiting this proinflammatory loop. IFN-β suppressed GM-CSF production in Th cells indirectly by acting on monocytes, and IFN-β signaling in monocytes was required for EAE suppression. IFN-β increased IL-10 expression by monocytes, and IL-10 was required for the suppressive effects of IFN-β. IFN-β treatment suppressed IL-1β expression by monocytes in the CNS of mice with EAE. GM-CSF from Th cells induced IL-1β production by monocytes, and, in a positive feedback loop, IL-1β augmented GM-CSF production by Th cells. In addition to GM-CSF, TNF and FASL expression by Th cells was also necessary for IL-1β production by monocyte. IFN-β inhibited GM-CSF, TNF, and FASL expression by Th cells to suppress IL-1β secretion by monocytes. Overall, our study describes a positive feedback loop involving several Th cell- and monocyte-derived molecules, and IFN-β actions on monocytes disrupting this proinflammatory loop.

Interleukin (IL)-37, a novel member of the IL-1 family of cytokines, has anti-inflammatory properties. It was shown that IL-37 suppresses innate immunity and allergic reactions by modulating dendritic cells (DCs) and mast cells and interfering with the mTOR pathway. Although multiple sclerosis (MS) patients have increased serum levels of IL-37; it is currently unknown whether IL-37 has a protective role in autoimmune neuroinflammation. Here we show that IL-37 suppresses experimental autoimmune encephalomyelitis (EAE), the prototypical animal model of MS, by ultimately inducing IL-10+ B cells. B cell-derived IL-10 was critical for EAE suppression when mice were treated with IL-37; however, IL-37 did not directly induce IL-10 in B cells. Instead, IL-37 triggered the mTORC2 pathway in DCs, leading to production of the tissue repair-associated cytokine amphiregulin (Areg), which stimulated CD4+ T cells to produce IL-21 and DCs to produce IL-27. Blockade of Areg, IL-21 and IL-27 revoked the protective effects of IL-37 by precluding an increase in the frequency of IL-10+ B cells. Our results describe an IL-37-Areg-IL-10 transcellular circuit that suppresses CNS autoimmune inflammation that can be further explored in future therapies for MS and other neuroinflammatory conditions.

Multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) are neuroinflammatory diseases of the central nervous system (CNS), where leukocytes and CNS resident cells play important roles in disease development and pathogenesis. The antimalarial drug chloroquine (CQ) has been shown to suppress EAE by modulating dendritic cells (DCs) and Th17 cells. However, the mechanism of action by which CQ modulates EAE is far from being elucidated. Here, we comprehensively analyzed the CNS of CQ and PBS-treated EAE mice to identify and characterize the cells that are affected by CQ. Our results show that leukocytes are largely modulated by CQ and have a reduction in the expression of inflammatory markers. Intriguingly, CQ vastly modulated the CNS resident cells astrocytes, oligodendrocytes (OLs) and microglia (MG), with the latter producing IL-10 and IL-12p70. Overall, our results show a panoramic view of the cellular components that are affect by CQ and provide further evidence that drug repurposing of CQ will be beneficial to MS patients.

Autoimmune diseases such as multiple sclerosis (MS) develop because of failed peripheral immune tolerance for a specific self-antigen (Ag). Numerous approaches for Ag-specific suppression of autoimmune neuroinflammation have been proven effective in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. One such approach is intravenous tolerance induction by injecting a myelin Ag used for triggering EAE. However, the translation of this and similar experimental strategies into therapy for MS has been hampered by uncertainty regarding relevant myelin Ags in MS patients. To address this issue, we developed a therapeutic strategy that relies on oligodendrocyte (Ol)-derived extracellular vesicles (Ol-EVs), which naturally contain multiple myelin Ags. Intravenous Ol-EV injection reduced disease pathophysiology in a myelin Ag-dependent manner, both prophylactically and therapeutically, in several EAE models. The treatment was safe and restored immune tolerance by inducing immunosuppressive monocytes and apoptosis of autoreactive CD4+ T cells. Furthermore, we showed that human Ols also released EVs containing most relevant myelin Ags, providing a basis for their use in MS therapy. These findings introduce an approach for suppressing central nervous system (CNS) autoimmunity in a myelin Ag-specific manner, without the need to identify the target Ag.

PURPOSE:Despite undergoing allogeneic hematopoietic stem cell transplantation (HCT), patients with acute myeloid leukemia (AML) with internal tandem duplication mutation in the FMS-like tyrosine kinase 3 gene (FLT3-ITD) have a poor prognosis, frequently relapse, and die as a result of AML. It is currently unknown whether a maintenance therapy using FLT3 inhibitors, such as the multitargeted tyrosine kinase inhibitor sorafenib, improves outcome after HCT.PATIENTS AND METHODS:In a randomized, placebo-controlled, double-blind phase II trial (SORMAIN; German Clinical Trials Register: DRKS00000591), 83 adult patients with FLT3-ITD-positive AML in complete hematologic remission after HCT were randomly assigned to receive for 24 months either the multitargeted and FLT3-kinase inhibitor sorafenib (n = 43) or placebo (n = 40 placebo). Relapse-free survival (RFS) was the primary endpoint of this trial. Relapse was defined as relapse or death, whatever occurred first.RESULTS:With a median follow-up of 41.8 months, the hazard ratio (HR) for relapse or death in the sorafenib group versus placebo group was 0.39 (95% CI, 0.18 to 0.85; log-rank P = .013). The 24-month RFS probability was 53.3% (95% CI, 0.36 to 0.68) with placebo versus 85.0% (95% CI, 0.70 to 0.93) with sorafenib (HR, 0.256; 95% CI, 0.10 to 0.65; log-rank P = .002). Exploratory data show that patients with undetectable minimal residual disease (MRD) before HCT and those with detectable MRD after HCT derive the strongest benefit from sorafenib.CONCLUSION:Sorafenib maintenance therapy reduces the risk of relapse and death after HCT for FLT3-ITD-positive AML.

Multiple sclerosis(MS)is a demyelinating autoimmune disease of the central nervous system(CNS).We have shown that oral administration of Bowman-Birk inhibitor(BBI),a soybean-derived serine protease inhibitor,suppresses disease in experimental autoimmune encephalomyelitis(EAE),1 a model of MS.We show here that the suppression is dependent on stimulator of interferon genes(STING)and the production of interferon-β(IFN-β)by F4/80+macrophages.Furthermore,we show that the absence of type I IFN receptor-a(IFNAR1)in myeloid cells precludes EAE suppression by BBI,demonstrating that IFN-β signaling in these cells is relevant for the beneficial effect of BBI.BBI also induces IFN-β production by human macrophages and monocytes in a STING-dependent manner,suggesting that BBI could have a therapeutic effect in MS similar to the one in EAE.

Multiple sclerosis and experimental autoimmune encephalomyelitis (EAE) are inflammatory diseases of the CNS in which Th17 cells play a major role in the disease pathogenesis. Th17 cells that secrete GM-CSF are pathogenic and drive inflammation of the CNS. IL-9 is a cytokine with pleiotropic functions, and it has been suggested that it controls the pathogenic inflammation mediated by Th17 cells, and IL-9R(-/-) mice develop more severe EAE compared with wild-type counterparts. However, the underlying mechanism by which IL-9 suppresses EAE has not been clearly defined. In this study, we investigated how IL-9 modulates EAE development. By using mice knockout for IL-9R, we show that more severe EAE in IL-9R(-/-) mice correlates with increased numbers of GM-CSF+ CD4(+) T cells and inflammatory dendritic cells (DCs) in the CNS. Furthermore, DCs from IL-9R(-/-) mice induced more GM-CSF production by T cells and exacerbated EAE upon adoptive transfer than did wild-type DCs. Our results suggest that IL-9 reduces autoimmune neuroinflammation by suppressing GM-CSF production by CD4(+) T cells through the modulation of DCs.