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Ex vivo expansion of human CD34+ hematopoietic stem and progenitor cells remains a challenge due to rapid differentiation after detachment from the bone marrow niche. In this study, we assessed the capacity of an inducible fusion protein to enable sustained ex vivo proliferation of hematopoietic precursors and their capacity to differentiate into functional phagocytes. We fused the coding sequences of an FK506-Binding Protein 12 (FKBP12)-derived destabilization domain (DD) to the myeloid/lymphoid lineage leukemia/eleven nineteen leukemia (MLL-ENL) fusion gene to generate the fusion protein DD-MLL-ENL and retrovirally expressed the protein switch in human CD34+ progenitors. Using Shield1, a chemical inhibitor of DD fusion protein degradation, we established large-scale and long-term expansion of late monocytic precursors. Upon Shield1 removal, the cells lost self-renewal capacity and spontaneously differentiated, even after 2.5 y of continuous ex vivo expansion. In the absence of Shield1, stimulation with IFN-γ, LPS, and GM-CSF triggered terminal differentiation. Gene expression analysis of the obtained phagocytes revealed marked similarity with naïve monocytes. In functional assays, the novel phagocytes migrated toward CCL2, attached to VCAM-1 under shear stress, produced reactive oxygen species, and engulfed bacterial particles, cellular particles, and apoptotic cells. Finally, we demonstrated Fcγ receptor recognition and phagocytosis of opsonized lymphoma cells in an antibody-dependent manner. Overall, we have established an engineered protein that, as a single factor, is useful for large-scale ex vivo production of human phagocytes. Such adjustable proteins have the potential to be applied as molecular tools to produce functional immune cells for experimental cell-based approaches.
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Diferenciação Celular , Fagócitos , Humanos , Fagócitos/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteína de Leucina Linfoide-Mieloide/metabolismo , Proteína de Leucina Linfoide-Mieloide/genética , Leucemia/genética , Leucemia/patologia , Leucemia/metabolismo , Engenharia de Proteínas/métodos , FagocitoseRESUMO
CD4+ T cells are central mediators of adaptive and innate immune responses and constitute a major reservoir for human immunodeficiency virus (HIV) in vivo. Detailed investigations of resting human CD4+ T cells have been precluded by the absence of efficient approaches for genetic manipulation limiting our understanding of HIV replication and restricting efforts to find a cure. Here we report a method for rapid, efficient, activation-neutral gene editing of resting, polyclonal human CD4+ T cells using optimized cell cultivation and nucleofection conditions of Cas9-guide RNA ribonucleoprotein complexes. Up to six genes, including HIV dependency and restriction factors, were knocked out individually or simultaneously and functionally characterized. Moreover, we demonstrate the knock in of double-stranded DNA donor templates into different endogenous loci, enabling the study of the physiological interplay of cellular and viral components at single-cell resolution. Together, this technique allows improved molecular and functional characterizations of HIV biology and general immune functions in resting CD4+ T cells.
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Linfócitos T CD4-Positivos/fisiologia , Sistemas CRISPR-Cas/genética , Edição de Genes/métodos , Infecções por HIV/genética , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/virologia , Proteína 9 Associada à CRISPR/genética , Movimento Celular/genética , Células Cultivadas , DNA , Técnicas de Inativação de Genes , Infecções por HIV/metabolismo , Humanos , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Proteínas de Resistência a Myxovirus/genética , Proteínas de Resistência a Myxovirus/metabolismo , RNA Guia de Cinetoplastídeos , Proteína 1 com Domínio SAM e Domínio HD/genética , Transgenes , Fatores de Poliadenilação e Clivagem de mRNA/genética , Fatores de Poliadenilação e Clivagem de mRNA/metabolismoRESUMO
BACKGROUND: The oncological impact of perioperative blood transfusions (PBTs) of patients undergoing radical cystectomy (RC) because of bladder cancer (BCa) has been a controversial topic discussed in recent years. The main cause for the contradictory findings of existing studies might be the missing consideration of the storage time of red blood cell units (BUs), donor age, and gender matching. STUDY DESIGN AND METHODS: We retrospectively analyzed BCa patients who underwent RC in our department between 2004 and 2021. We excluded patients receiving BUs before RC, >10 BUs, or RC in a palliative setting. We assessed the effect of blood donor characteristics and storage time on overall survival (OS) and cancer-specific survival (CSS) through univariate and multivariable Cox regression analysis. We also performed a propensity score matching with patients who received BUs and patients who did not on a 1:1 ratio. RESULTS: We screened 1692 patients and included 676 patients for the propensity score matching. In the multivariable analysis, PBT was independently associated with worse OS and CSS (p < .001). Postoperative transfusions were associated with better OS (p = .004) and CSS (p = .008) compared to intraoperative or mixed transfusions. However, there was no influence of blood donor age, storage time, or gender matching on prognosis. DISCUSSION: In our study of BCa patients undergoing RC, we demonstrate that PBT, especially if administered intraoperatively, is an independent risk factor for a worse prognosis. However, storage time, donor age, or gender matching did not negatively affect oncological outcomes. Therefore, the specific selection of blood products does not promise any benefits.
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Cistectomia , Neoplasias da Bexiga Urinária , Humanos , Estudos Retrospectivos , Neoplasias da Bexiga Urinária/cirurgia , Transfusão de Sangue , Prognóstico , Resultado do TratamentoRESUMO
Introduction: Primary human blood cells represent an essential model system to study physiology and disease. However, human blood is a limited resource. During healthy donor plateletpheresis, the leukoreduction system chamber (LRSC) reduces the leukocyte amount within the subsequent platelet concentrate through saturated, fluidized, particle bed filtration technology. Normally, the LRSC is discarded after apheresis is completed. Compared to peripheral blood, LRSC yields 10-fold mononuclear cell concentration. Methods: To explore if those retained leukocytes are attractive for research purposes, we isolated CD3+ T cells from the usually discarded LRSCs via density gradient centrifugation in order to manufacture CD19-targeted chimeric antigen receptor (CAR) T cells. Results: Immunophenotypic characterization revealed viable and normal CD4+ and CD8+ T-cell populations within LRSC, with low CD19+ B cell counts. Magnetic-activated cell sorting (MACS) purified CD3+ T cells were transduced with CD19 CAR-encoding lentiviral self-inactivating vectors using concentrated viral supernatants. Robust CD19 CAR cell surface expression on transduced T cells was confirmed by flow cytometry. CD19 CAR T cells were further enriched through anti-CAR MACS, yielding 80% CAR+ T-cell populations. In vitro CAR T cell expansion to clinically relevant numbers was achieved. To prove functionality, CAR T cells were co-incubated with the human CD19+ B cell precursor leukemia cell line Nalm6. Compared to unmodified T cells, CD19 CAR T cells effectively eradicated Nalm6 cells. Conclusion: Taken together, we can show that lymphocytes isolated from LRSCs of plateletpheresis sets can be efficiently used for the generation of functional CAR T cells for experimental purposes.
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Background and Objectives: A sufficient supply of safe, high-quality blood components for transfusion is essential to the healthcare system in Germany. The requirements for the current reporting system are laid down in the German Transfusion Act. The present work elaborates on the advantages and limitations of the current reporting system and investigates the feasibility of a pilot project that collects specific data on blood supply based on weekly reports. Materials and Methods: Selected data on blood collection and supply from 2009 to 2021 derived from the §21 German Transfusion Act database were examined. In addition, a pilot study over a period of 12 months was conducted on a voluntary basis. The number of red blood cell (RBC) concentrates was documented and stock availability was calculated weekly. Results: From 2009 to 2021, the annual number of RBC concentrates decreased from 4.68 to 3.43 million, the per capita distribution decreased from 58 to 41 RBC concentrates per 1,000 inhabitants. These figures did not change significantly during the COVID-19 pandemic. The data of the 1-year pilot project represented 77% of the released RBC concentrates in Germany. Percentage share of O RhD positive RBC concentrates fluctuated between 35% and 22% and for O RhD negative concentrates between 17% and 5%. The availability of O RhD positive RBC concentrate stocks varied between 2.1 and 7.6 days. Conclusion: The data presented shows a decrease in annual RBC concentrate sales over an 11-year period and no further change over the past 2 years. A weekly monitoring of blood components detects acute problems in RBC provision and supply. Close monitoring seems helpful but should be combined with a nationwide supply strategy.
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Natural killer group 2 member D (NKG2D) plays an important role in the regulation of natural killer (NK) cell cytotoxicity in cancer immune surveillance. With the aim of redirecting NK cell cytotoxicity against tumors, the NKG2D ligand UL-16 binding protein 2 (ULBP2) was fused to a single-chain fragment variable (scFv) targeting the human epidermal growth factor receptor 2 (HER2). The resulting bispecific immunoligand ULBP2:HER2-scFv triggered NK cell-mediated killing of HER2-positive breast cancer cells in an antigen-dependent manner and required concomitant interaction with NKG2D and HER2 as revealed in antigen blocking experiments. The immunoligand induced tumor cell lysis dose-dependently and was effective at nanomolar concentrations. Of note, ULBP2:HER2-scFv sensitized tumor cells for antibody-dependent cell-mediated cytotoxicity (ADCC). In particular, the immunoligand enhanced ADCC by cetuximab, a therapeutic antibody targeting the epidermal growth factor receptor (EGFR) synergistically. No significant improvements were obtained by combining cetuximab and anti-HER2 antibody trastuzumab. In conclusion, dual-dual targeting by combining IgG1 antibodies with antibody constructs targeting another tumor associated antigen and engaging NKG2D as a second NK cell trigger molecule may be promising. Thus, the immunoligand ULBP2:HER2-scFv may represent an attractive biological molecule to promote NK cell cytotoxicity against tumors and to boost ADCC.
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Neoplasias da Mama , Subfamília K de Receptores Semelhantes a Lectina de Células NK , Citotoxicidade Celular Dependente de Anticorpos , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Cetuximab/farmacologia , Cetuximab/uso terapêutico , Feminino , Humanos , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismo , Subfamília K de Receptores Semelhantes a Lectina de Células NK/uso terapêutico , Trastuzumab/farmacologia , Trastuzumab/uso terapêuticoRESUMO
The pandemic spread of an infectious disease poses a plethora of challenges to society, clinicians, health care providers and regulating authorities. In order to mount a rapid response and to provide hope in a potentially catastrophic situation as the current COVID-19 pandemic, emergency plans, regulations and funding strategies have to be developed on regional, national and international levels. The speed needed to establish rapid response programs is challenged by the dynamics of the spread of the disease, the concurrent and competing development of different and potentially more effective treatment options, and not the least by regulatory uncertainty. Convalescent plasma, that is plasma collected from patients who have recovered from COVID-19 infections, has emerged as one of the first potential treatment options in the absence of drugs or vaccines with proven efficacy against SARS-CoV-2. The societal aspects of convalescent plasma and the public awareness gave an additional boost to the rapid employment of convalescent plasma donation platforms immediately after the SARS-CoV-2 outbreak. At the same time, uncertainty remains as to the efficacy of convalescent plasma. With evidence mostly limited to empirical reports, convalescent plasma has been used for decades for the prophylaxis and treatment of various infectious diseases. Clinical trials have addressed different infectious agents, stages of disease, target groups of patients and yielded sometimes inconclusive results. The aim of this short review is to delineate the regulatory background for the emergency use of convalescent plasma in the USA, in the European Union and in Germany, and the transition to the setting of clinical trials. In addition, we describe observations made in the process of collecting COVID-19 convalescent plasma (herein referred to as CCP), and formulate proposals to further improve the framework for rapid responses in future emergency situations.
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Integrin associated protein (CD47) is an important target in immunotherapy, as it is expressed as a "don't eat me" signal on many tumor cells. Interference with its counter molecule signal regulatory protein alpha (SIRPα), expressed on myeloid cells, can be achieved with blocking Abs, but also by inhibiting the enzyme glutaminyl cyclase (QC) with small molecules. Glutaminyl cyclase inhibition reduces N-terminal pyro-glutamate formation of CD47 at the SIRPα binding site. Here, we investigated the impact of QC inhibition on myeloid effector cell-mediated tumor cell killing by epidermal growth factor receptor (EGFR) Abs and the influence of Ab isotypes. SEN177 is a QC inhibitor and did not interfere with EGFR Ab-mediated direct growth inhibition, complement-dependent cytotoxicity, or Ab-dependent cell-mediated cytotoxicity (ADCC) by mononuclear cells. However, binding of a human soluble SIRPα-Fc fusion protein to SEN177 treated cancer cells was significantly reduced in a dose-dependent manner, suggesting that pyro-glutamate formation of CD47 was affected. Glutaminyl cyclase inhibition in tumor cells translated into enhanced Ab-dependent cellular phagocytosis by macrophages and enhanced ADCC by polymorphonuclear neutrophilic granulocytes. Polymorphonuclear neutrophilic granulocyte-mediated ADCC was significantly more effective with EGFR Abs of human IgG2 or IgA2 isotypes than with IgG1 Abs, proposing that the selection of Ab isotypes could critically affect the efficacy of Ab therapy in the presence of QC inhibition. Importantly, QC inhibition also enhanced the therapeutic efficacy of EGFR Abs in vivo. Together, these results suggest a novel approach to specifically enhance myeloid effector cell-mediated efficacy of EGFR Abs by orally applicable small molecule QC inhibitors.
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Aminoaciltransferases/antagonistas & inibidores , Antígenos de Diferenciação/química , Antineoplásicos Imunológicos/administração & dosagem , Antígeno CD47/metabolismo , Neoplasias/tratamento farmacológico , Receptores Imunológicos/química , Bibliotecas de Moléculas Pequenas/administração & dosagem , Animais , Antígenos de Diferenciação/metabolismo , Antineoplásicos Imunológicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cetuximab/administração & dosagem , Cetuximab/farmacologia , Sinergismo Farmacológico , Feminino , Células HEK293 , Humanos , Masculino , Camundongos , Neoplasias/metabolismo , Panitumumabe/administração & dosagem , Panitumumabe/farmacologia , Ligação Proteica/efeitos dos fármacos , Receptores Imunológicos/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
During infection with the human immunodeficiency virus type 1 (HIV-1), latent reservoirs are established that circumvent full eradication of the virus by antiretroviral therapy (ART) and are the source for viral rebound after cessation of therapy. As these reservoirs are phenotypically indistinguishable from infected cells, current strategies aim to reactivate these reservoirs, followed by pharmaceutical and immunological destruction of the cells. Here, we employed a simple and convenient cell-based reporter system, which enables sample handling under biosafety level (BSL)-1 conditions, to screen for compounds that were able to reactivate latent HIV-1. The assay showed a high dynamic signal range and reproducibility with an average Z-factor of 0.77, classifying the system as robust. The assay was used for high-throughput screening (HTS) of an epigenetic compound library in combination with titration and cell-toxicity studies and revealed several potential new latency-reversing agents (LRAs). Further validation in well-known latency model systems verified earlier studies and identified two novel compounds with very high reactivation efficiencies and low toxicity. Both drugs, namely, N-hydroxy-4-(2-[(2-hydroxyethyl)(phenyl)amino]-2-oxoethyl)benzamide (HPOB) and 2',3'-difluoro-[1,1'-biphenyl]-4-carboxylic acid, 2-butylhydrazide (SR-4370), showed comparable performances to other already known LRAs, did not activate CD4+ T cells, and did not cause changes in the composition of peripheral blood mononuclear cells (PBMCs), as shown by flow cytometry analyses. Both compounds may represent effective new treatment possibilities for reversal of latency in HIV-1-infected individuals.
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Infecções por HIV , HIV-1 , Linfócitos T CD4-Positivos , Epigênese Genética , Infecções por HIV/tratamento farmacológico , HIV-1/genética , Humanos , Leucócitos Mononucleares , Reprodutibilidade dos Testes , Ativação Viral , Latência ViralRESUMO
Prior to the COVID-19 crisis, global air transport demand was expected to triple between 2020 and 2050. The pandemic, which reduced global air travel significantly, provides an opportunity to discuss the scale, distribution and growth of aviation until 2018, also with a view to consider the climate change implications of a return to volume growth. Industry statistics, data provided by supranational organizations, and national surveys are evaluated to develop a pre-pandemic understanding of air transport demand at global, regional, national and individual scales. Results suggest that the share of the world's population travelling by air in 2018 was 11%, with at most 4% taking international flights. Data also supports that a minor share of air travelers is responsible for a large share of warming: The percentile of the most frequent fliers - at most 1% of the world population - likely accounts for more than half of the total emissions from passenger air travel. Individual users of private aircraft can contribute to emissions of up to 7,500 t CO2 per year. Findings are specifically relevant with regard to the insight that a large share of global aviation emissions is not covered by policy agreements.
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Since almost 30 years, lung transplantation is a considerable therapeutic option in patients suffering from end-stage lung disease. Up to now, the impact of donor-specific antibodies directed against donor HLA (human leukocyte antigen) before and after transplantation is still a matter of debate. As histocompatibility testing is not required for each patient according to the current national guidelines and Eurotransplant recommendations for lung transplantation, each transplantation unit has to establish a local protocol together with the tissue typing laboratory how to implement an immunological risk assessment strategy for their patients while enabling access to transplantation. Desensitization regimens might help in case of highly alloimmunized patients waiting for urgent transplantation.
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For years, cancer treatment was dominated by chemotherapy, radiation therapy, and stem cell transplantation. New insights into genetic characteristics of leukemic cells have initiated the development of the chimeric antigen receptor (CAR) T-cell therapy. This type of adoptive cell immunotherapy has been a breakthrough in the treatment of aggressive B-cell lymphoma and B-cell precursor acute lymphoblastic leukemia. In August 2018, the European Commission has approved the first CAR T-cell products - tisagenlecleucel (Kymriah®, Novartis) and axicabtagene ciloleucel (Yescarta®, Gilead) - for hematological neoplasms in Europe. As CAR T cells are a living drug, its benefits can last for many years. The administration of CAR T cells is a complex and costly endeavor involving cell manufacture, shipping of apheresis products, and management of novel and severe adverse reactions. The most common toxicities observed after CAR T-cell therapy are cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome. Current research focuses on improved safety and efficacy in hematological malignancies as well as the translation of CAR T-cell therapy to solid tumors. This review covers the development and current status of CAR T-cell therapy in a clinical setting with focus on challenges and future opportunities.
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Once a cohort exceeds a certain size, it becomes mandatory to assign an identifier (ID) for each individual to ensure a secure, reliable, and unambiguous assignment. In the field of hematopoietic stem cell transplantation, with a still growing number of voluntary unrelated donors, it was recognized that a system needs to be developed to uniquely identify potential donors on a global scale to facilitate communication and to prevent errors in identification of donors. Efforts in this respect resulted in establishment of the GRID, with a defined structure and allocated rules. To successfully implement such a project, collaboration among all organizations involved in the process of volunteer donor recruitment, facilitation, and provision of hematopoietic stem cell products is necessary. Therefore, rapidly accessible information combined with a high level of communication and exchange of experiences is crucial. Established systems like the ISBT 128 and the Single European Code (SEC), which standardize the terminology, identification, coding, and labeling of tissues and cells of human origin, serve as a basis on how to successfully implement the GRID on a global scale.
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Induced self expression of the NKp30 ligand B7-H6 facilitates NK cell-mediated elimination of stressed cells. A fusion protein consisting of the ectodomain of B7-H6 and the CD20 single-chain fragment variable 7D8 was generated to mimic an induced self phenotype required for NK cell-mediated target cell elimination. B7-H6:7D8 had bifunctional properties as reflected by its ability to simultaneously bind to the CD20 Ag and to the NKp30 receptor. B7-H6:7D8 bound by CD20(+) lymphoma cells activated human NK cells and triggered degranulation. Consequently, the immunoligand B7-H6:7D8 induced killing of lymphoma-derived cell lines as well as fresh tumor cells from chronic lymphocytic leukemia or lymphoma patients. B7-H6:7D8 was active at nanomolar concentrations in a strictly Ag-specific manner and required interaction with both CD20 and NKp30. Remarkably, NK cell cytotoxicity was further augmented by concomitant activation of Fcγ receptor IIIa or NK group 2 member D. Thus, B7-H6:7D8 acted synergistically with the CD20 Ab rituximab and the immunoligand ULBP2:7D8, which was similarly designed as B7-H6:7D8 but engaging the NK group 2 member D receptor. In conclusion, to our knowledge, B7-H6:7D8 represents the first Ab-based molecule stimulating NKp30-mediated NK cell cytotoxicity for therapeutic purposes and provides proof of concept that Ag-specific NKp30 engagement may represent an innovative strategy to enhance antitumoral NK cell cytotoxicity.
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Antígenos B7/farmacologia , Degranulação Celular/efeitos dos fármacos , Imunidade Celular/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Ativação Linfocitária/efeitos dos fármacos , Linfoma/terapia , Receptor 3 Desencadeador da Citotoxicidade Natural/imunologia , Anticorpos Monoclonais Murinos/imunologia , Anticorpos Monoclonais Murinos/farmacologia , Antígenos CD20/genética , Antígenos CD20/imunologia , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Antineoplásicos/imunologia , Antineoplásicos/farmacologia , Antígenos B7/agonistas , Antígenos B7/genética , Degranulação Celular/genética , Degranulação Celular/imunologia , Linhagem Celular Tumoral , Sinergismo Farmacológico , Humanos , Imunidade Celular/genética , Imunoterapia , Ativação Linfocitária/genética , Linfoma/genética , Linfoma/imunologia , Receptor 3 Desencadeador da Citotoxicidade Natural/genética , Receptores de IgG , RituximabRESUMO
While air transport decarbonization is theoretically feasible, less attention has been paid to the complexity incurred in various 'transition barriers' that act as roadblocks to net-zero goals. A total of 40 barriers related to mitigation, management, technology and fuel transition, finance, and governance are identified. As these make decarbonization uncertain, the paper analyzes air transport system's growth, revenue, and profitability. Over the period 1978-2022, global aviation has generated marginal profits of US$20200.94 per passenger, or US$202082 billion in total. Low profitability makes it unlikely that the sector can finance the fuel transition cost, at US$0.5-2.1 trillion (Dray et al. 2022). Four radical policy scenarios for air transport futures are developed. All are characterized by "limitations", such as CO2 taxes, a carbon budget, alternative fuel obligations, or available capacity. Scenario runs suggest that all policy scenarios will more reliably lead to net-zero than the continued volume growth model pursued by airlines.
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CD19-directed immunotherapy has become a cornerstone in the therapy of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). CD19-directed cellular and antibody-based therapeutics have entered therapy of primary and relapsed disease and contributed to improved outcomes in relapsed disease and lower therapy toxicity. However, efficacy remains limited in many cases due to a lack of therapy response, short remission phases, or antigen escape. Here, BCP-ALL cell lines, patient-derived xenograft (PDX) samples, human macrophages, and an in vivo transplantation model in NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice were used to examine the therapeutic potency of a CD19 antibody Fc-engineered for improved effector cell recruitment (CD19-DE) and antibody-dependent cellular phagocytosis (ADCP), in combination with a novel modified CD47 antibody (Hu5F9-IgG2σ). For the in vivo model, only samples refractory to CD19-DE monotherapy were chosen. Hu5F9-IgG2σ enhanced ADCP by CD19-DE in various BCP-ALL cell line models with varying CD19 surface expression and cytogenetic backgrounds, two of which contained the KMT2A-AFF1 fusion. Also, the antibody combination was efficient in inducing ADCP by human macrophages in pediatric PDX samples with and adult samples with and without KMT2A-rearrangement in vitro. In a randomized phase 2-like PDX trial using seven KMT2A-rearranged BCP-ALL samples in NSG mice, the CD19/CD47 antibody combination proved highly efficient. Our findings support that the efficacy of Fc-engineered CD19 antibodies may be substantially enhanced by a combination with CD47 blockade. This suggests that the combination may be a promising therapy option for BCP-ALL, especially in relapsed patients and/or patients refractory to CD19-directed therapy.
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Immune cell phenotyping frequently detects lineage-unrelated receptors. Here, we report that surface receptors can be transferred from primary macrophages to CD4 T cells and identify the Fcγ receptor CD32 as driver and cargo of this trogocytotic transfer. Filamentous CD32+ nanoprotrusions deposit distinct plasma membrane patches onto target T cells. Transferred receptors confer cell migration and adhesion properties, and macrophage-derived membrane patches render resting CD4 T cells susceptible to infection by serving as hotspots for HIV-1 binding. Antibodies that recognize T cell epitopes enhance CD32-mediated trogocytosis. Such autoreactive anti-HIV-1 envelope antibodies can be found in the blood of HIV-1 patients and, consistently, the percentage of CD32+ CD4 T cells is increased in their blood. This CD32-mediated, antigen-independent cell communication mode transiently expands the receptor repertoire and functionality of immune cells. HIV-1 hijacks this mechanism by triggering the generation of trogocytosis-promoting autoantibodies to gain access to immune cells critical to its persistence.
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Infecções por HIV , Soropositividade para HIV , HIV-1 , Humanos , Linfócitos T CD4-Positivos , Receptores de IgG/metabolismo , Autoanticorpos/metabolismo , TrogocitoseRESUMO
Patients with relapsed or refractory advanced T cell non-Hodgkin lymphoma have a dismal prognosis and may not even reach allogeneic hematopoietic stem cell transplantation (HSCT) in adequate condition. We present the outcome of 24 consecutive patients (age range 11 to 65 years) treated at a single institution in Kiel within a recent 5.5-year time frame with allogeneic HSCT in a rather uniform approach. Relapsed and refractory T and natural killer cell lymphomas of various subtypes were included. All patients except 1 were in progression or relapse before start of pretransplantation salvage therapy. Five patients had relapsed after autologous HSCT. With intensive remission induction therapy, usually the CLAEG (cladribine, cytosine arabinoside, and etoposide with granulocyte colony-stimulating factor support) protocol, attempts were made to improve disease control and proceed immediately to conditioning with carmustine, etoposide, cytosine arabinoside, melphalan (BEAM), and medium-dose alemtuzumab. Twenty of 21 patients who received CLAEG induction therapy benefited from this protocol and 1 patient appeared to be therapy-resistant. At the time of allogeneic HSCT, 9 patients were in complete remission (CR) (2 in CR1, 5 in CR2, and 2 in CR >2), whereas 50% had never achieved CR. Nineteen transplants were obtained from matched or partially matched unrelated donors and only 5 from siblings. With a median follow-up of 321 days (1252 days for surviving patients), 20 of 22 assessable patients reached CR. Five of these patients had hematologic or molecular relapse. With donor lymphocyte infusions, 1 patient became minimal residual disease MRD negative again and has maintained CR for more than 4 years. The frequency of grades II to IV acute graft-versus-host disease was 25% and chronic graft-versus-host disease, 30%. Intense reinduction therapy followed by reduced-intensity BEAM-alemtuzumab conditioning and allogeneic HSCT is effective and offers curative potential for patients with advanced T cell lymphomas, even for those not in remission.