scholarly journals Rituximab-resistant splenic memory B cells and newly engaged naive B cells fuel relapses in patients with immune thrombocytopenia

2021 ◽  
Vol 13 (589) ◽  
pp. eabc3961
Author(s):  
Etienne Crickx ◽  
Pascal Chappert ◽  
Aurélien Sokal ◽  
Sandra Weller ◽  
Imane Azzaoui ◽  
...  
Keyword(s):  
B Cells ◽  
Autoimmune Diseases ◽  
B Cell ◽  
Single Cell ◽  
Immune Thrombocytopenia ◽  
Plasma Cells ◽  
Surface Expression ◽  
Memory B Cells ◽  
Gene Repertoire ◽  
Immunoglobulin Gene

Rituximab (RTX), an antibody targeting CD20, is widely used as a first-line therapeutic strategy in B cell–mediated autoimmune diseases. However, a large proportion of patients either do not respond to the treatment or relapse during B cell reconstitution. Here, we characterize the cellular basis responsible for disease relapse in secondary lymphoid organs in humans, taking advantage of the opportunity offered by therapeutic splenectomy in patients with relapsing immune thrombocytopenia. By analyzing the B and plasma cell immunoglobulin gene repertoire at bulk and antigen-specific single-cell level, we demonstrate that relapses are associated with two responses coexisting in germinal centers and involving preexisting mutated memory B cells that survived RTX treatment and naive B cells generated upon reconstitution of the B cell compartment. To identify distinctive characteristics of the memory B cells that escaped RTX-mediated depletion, we analyzed RTX refractory patients who did not respond to treatment at the time of B cell depletion. We identified, by single-cell RNA sequencing (scRNA-seq) analysis, a population of quiescent splenic memory B cells that present a unique, yet reversible, RTX-shaped phenotype characterized by down-modulation of B cell–specific factors and expression of prosurvival genes. Our results clearly demonstrate that these RTX-resistant autoreactive memory B cells reactivate as RTX is cleared and give rise to plasma cells and further germinal center reactions. Their continued surface expression of CD19 makes them efficient targets for current anti-CD19 therapies. This study thus identifies a pathogenic contributor to autoimmune diseases that can be targeted by available therapeutic agents.

A reservoir of rituximab-resistant splenic memory B cells contributes to relapses after B-cell depletion therapy

2019 ◽  
Author(s):  
Etienne Crickx ◽  
Pascal Chappert ◽  
Sandra Weller ◽  
Aurélien Sokal ◽  
Imane Azzaoui ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Plasma Cells ◽  
Complete Response ◽  
Memory B Cells ◽  
Chain Gene ◽  
Gene Repertoire ◽  
Heavy Chain Gene ◽  
Immunoglobulin Heavy Chain Gene ◽  
Pathogenic Antibodies

AbstractImmune thrombocytopenia (ITP) is an autoimmune disease mediated by pathogenic antibodies directed against platelet antigens, including GPIIbIIIa. Taking advantage of spleen samples obtained from ITP patients, we characterized by multiples approaches the onset of disease relapses occurring after an initial complete response to rituximab. Analysis of splenic B cell immunoglobulin heavy chain gene repertoire at bulk level and from single anti-GPIIbIIIa B cells revealed that germinal centers were fueled by B cells originating from the ongoing lymphopoiesis, but also by rituximab-resistant memory B cells, both giving rise to anti-GPIIbIIIa plasma cells. We identified a population of splenic memory B cells that resisted rituximab through acquisition of a unique phenotype and contributed to relapses, providing a new target in B cell mediated autoimmune diseases.

scholarly journals A pathogenic and clonally expanded B cell transcriptome in active multiple sclerosis

2020 ◽  
Vol 117 (37) ◽  
pp. 22932-22943 ◽  
Author(s):  
Akshaya Ramesh ◽  
Ryan D. Schubert ◽  
Ariele L. Greenfield ◽  
Ravi Dandekar ◽  
Rita Loudermilk ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
B Cells ◽  
B Cell ◽  
Single Cell ◽  
Rna Sequencing ◽  
Chemokine Receptors ◽  
Plasma Cells ◽  
Cholesterol Biosynthesis ◽  
Memory B Cells ◽  
Cell Phenotype

Central nervous system B cells have several potential roles in multiple sclerosis (MS): secretors of proinflammatory cytokines and chemokines, presenters of autoantigens to T cells, producers of pathogenic antibodies, and reservoirs for viruses that trigger demyelination. To interrogate these roles, single-cell RNA sequencing (scRNA-Seq) was performed on paired cerebrospinal fluid (CSF) and blood from subjects with relapsing-remitting MS (RRMS; n = 12), other neurologic diseases (ONDs; n = 1), and healthy controls (HCs; n = 3). Single-cell immunoglobulin sequencing (scIg-Seq) was performed on a subset of these subjects and additional RRMS (n = 4), clinically isolated syndrome (n = 2), and OND (n = 2) subjects. Further, paired CSF and blood B cell subsets (RRMS; n = 7) were isolated using fluorescence activated cell sorting for bulk RNA sequencing (RNA-Seq). Independent analyses across technologies demonstrated that nuclear factor kappa B (NF-κB) and cholesterol biosynthesis pathways were activated, and specific cytokine and chemokine receptors were up-regulated in CSF memory B cells. Further, SMAD/TGF-β1 signaling was down-regulated in CSF plasmablasts/plasma cells. Clonally expanded, somatically hypermutated IgM+ and IgG1+ CSF B cells were associated with inflammation, blood–brain barrier breakdown, and intrathecal Ig synthesis. While we identified memory B cells and plasmablast/plasma cells with highly similar Ig heavy-chain sequences across MS subjects, similarities were also identified with ONDs and HCs. No viral transcripts, including from Epstein–Barr virus, were detected. Our findings support the hypothesis that in MS, CSF B cells are driven to an inflammatory and clonally expanded memory and plasmablast/plasma cell phenotype.

scholarly journals Signatures of B Cell Receptor Repertoire Following Pneumocystis Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Han Sun ◽  
Hu-Qin Yang ◽  
Kan Zhai ◽  
Zhao-Hui Tong
Keyword(s):  
B Cells ◽  
B Cell ◽  
Single Cell ◽  
Plasma Cells ◽  
Somatic Hypermutation ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Receptor Repertoire ◽  
Elevated Expression ◽  
Pneumocystis Infection

B cells play vital roles in host defense against Pneumocystis infection. However, the features of the B cell receptor (BCR) repertoire in disease progression remain unclear. Here, we integrated single-cell RNA sequencing and single-cell BCR sequencing of immune cells from mouse lungs in an uninfected state and 1–4 weeks post-infection in order to illustrate the dynamic nature of B cell responses during Pneumocystis infection. We identified continuously increased plasma cells and an elevated ratio of (IgA + IgG) to (IgD + IgM) after infection. Moreover, Pneumocystis infection was associated with an increasing naïve B subset characterized by elevated expression of the transcription factor ATF3. The proportion of clonal expanded cells progressively increased, while BCR diversity decreased. Plasma cells exhibited higher levels of somatic hypermutation than naïve B cells. Biased usage of V(D)J genes was observed, and the usage frequency of IGHV9-3 rose. Overall, these results present a detailed atlas of B cell transcriptional changes and BCR repertoire features in the context of Pneumocystis infection, which provides valuable information for finding diagnostic biomarkers and developing potential immunotherapeutic targets.

scholarly journals Potential anti-EBV effects associated with elevated interleukin-21 levels: a case report

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Kristian Assing ◽  
Christian Nielsen ◽  
Marianne Jakobsen ◽  
Charlotte B. Andersen ◽  
Kristin Skogstrand ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Plasma Cell ◽  
Germinal Center ◽  
Plasma Cells ◽  
Cell Formation ◽  
Memory B Cells ◽  
Memory B Cell

Abstract Background Germinal center derived memory B cells and plasma cells constitute, in health and during EBV reactivation, the largest functional EBV reservoir. Hence, by reducing germinal center derived formation of memory B cells and plasma cells, EBV loads may be reduced. Animal and in-vitro models have shown that IL-21 can support memory B and plasma cell formation and thereby potentially contribute to EBV persistence. However, IL-21 also displays anti-viral effects, as mice models have shown that CD4+ T cell produced IL-21 is critical for the differentiation, function and survival of anti-viral CD8+ T cells able to contain chronic virus infections. Case presentation We present immunological work-up (flow-cytometry, ELISA and genetics) related to a patient suffering from a condition resembling B cell chronic active EBV infection, albeit with moderately elevated EBV copy numbers. No mutations in genes associated with EBV disease, common variable immunodeficiency or pertaining to the IL-21 signaling pathway (including hypermorphic IL-21 mutations) were found. Increased (> 5-fold increase 7 days post-vaccination) CD4+ T cell produced (p < 0.01) and extracellular IL-21 levels characterized our patient and coexisted with: CD8+ lymphopenia, B lymphopenia, hypogammaglobulinemia, compromised memory B cell differentiation, absent induction of B-cell lymphoma 6 protein (Bcl-6) dependent peripheral follicular helper T cells (pTFH, p = 0.01), reduced frequencies of peripheral CD4+ Bcl-6+ T cells (p = 0.05), compromised plasmablast differentiation (reduced protein vaccine responses (p < 0.001) as well as reduced Treg frequencies. Supporting IL-21 mediated suppression of pTFH formation, pTFH and CD4+ IL-21+ frequencies were strongly inversely correlated, prior to and after vaccination, in the patient and in controls, Spearman’s rho: − 0.86, p < 0.001. Conclusions To the best of our knowledge, this is the first report of elevated CD4+ IL-21+ T cell frequencies in human EBV disease. IL-21 overproduction may, apart from driving T cell mediated anti-EBV responses, disrupt germinal center derived memory B cell and plasma cell formation, and thereby contribute to EBV disease control.

scholarly journals Hyperproliferation of B Cells Specific for a Weakly Immunogenic PorA in a Meningococcal Vaccine Model

2008 ◽  
Vol 15 (10) ◽  
pp. 1598-1605 ◽  
Author(s):  
Thomas A. Luijkx ◽  
Jacqueline A. M. van Gaans-van den Brink ◽  
Harry H. van Dijken ◽  
Germie P. J. M. van den Dobbelsteen ◽  
Cécile A. C. M. van Els
Keyword(s):  
B Cells ◽  
B Cell ◽  
Bactericidal Activity ◽  
Plasma Cells ◽  
Affinity Maturation ◽  
Memory B Cells ◽  
Vaccine Antigen ◽  
Cell Subpopulation ◽  
Cell Subpopulations ◽  
Group B

ABSTRACT Highly homologous meningococcal porin A (PorA) proteins induce protective humoral immunity against Neisseria meningitidis group B infection but with large and consistent differences in the levels of serum bactericidal activity achieved. We investigated whether a poor PorA-specific serological outcome is associated with a limited size of the specific B-cell subpopulation involved. The numbers of PorA-specific splenic plasma cells, bone marrow (BM) plasma cells, and splenic memory B cells were compared between mice that received priming and boosting with the weakly immunogenic PorA (P1.7-2,4) protein and those that received priming and boosting with the highly immunogenic PorA (P1.5-1,2-2) protein. Immunoglobulin G (IgG) titers (except at day 42), bactericidal activity, and the avidity of IgG produced against P1.7-2,4 were significantly lower at all time points after priming and boosting than against P1.5-1,2-2. These differences, however, were not associated with a lack of P1.7-2,4-specific plasma cells. Instead, priming with both of the PorAs resulted in the initial expansion of comparable numbers of splenic and BM plasma cells. Moreover, P1.7-2,4-specific BM plasma cells, but not P1.5-1,2-2-specific plasma cells, expanded significantly further after boosting. Likewise, after a relative delay during the priming phase, the splenic P1.7-2,4-specific memory B cells largely outnumbered those specific for P1.5-1,2-2, upon boosting. These trends were observed with different vaccine formulations of the porins. Our results show for the first time that B-cell subpopulations involved in a successfully maturated antibody response against a clinically relevant vaccine antigen are maintained at smaller population sizes than those associated with poor affinity maturation. This bears consequences for the interpretation of immunological memory data in clinical vaccine trials.

scholarly journals Effects of Rituximab and Dexamethasone on Regulatory and Pro-Inflammatory B-Cell Subsets in Patients with Primary Immune Thrombocytopenia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1378-1378
Author(s):  
Sif Gudbrandsdottir ◽  
Marie Brimnes ◽  
Tania Kollgaard ◽  
Hans Carl Hasselbalch ◽  
Claus Henrik Nielsen
Keyword(s):  
B Cells ◽  
Autoimmune Diseases ◽  
B Cell ◽  
Research Funding ◽  
Immune Thrombocytopenia ◽  
Lower Proportion ◽  
Surface Markers ◽  
Healthy Controls ◽  
Cell Functions ◽  
Primary Immune Thrombocytopenia

Abstract Background B-cell depletion with rituximab (RTX) is widely accepted as first- or second-line therapy in primary immune thrombocytopenia (ITP), but it is still unclear how RTX mediates its positive effect in ITP patients. RTX has been reported to induce a reduced titer of platelet antibodies. However, this finding is inconsistent and other B-cell functions, such as the ability to secrete cytokines or to function as antigen-presenting cells for T cells, may be involved in the pathogenesis of ITP. Evidence suggests that B cells participate in the regulation of autoimmune diseases by virtue of their ability to produce the regulatory cytokines interleukin (IL)-10, IL-35, or transforming growth factor β. The various functions of B cells involved in the pathogenesis of autoimmune diseases can in part be deducted by their phenotype as recognized by measurement of specific surface markers and cytokine secretion. Materials and Methods We previously conducted a trial involving 137 newly diagnosed adult ITP patients randomized to treatment with RTX (375 mg/m2/week for 4 weeks) + dexamethasone (DXM) (40 mg/day for 4 days repeated up to 6 cycles) or DXM monotherapy. From this cohort, we identified 16 patients with available samples of peripheral blood mononuclear cells (PBMCs) at baseline and 12 months after treatment; 9 patients from the RTX+DXM group, 7 patients from the DXM group. Seven anonymous blood donors served as healthy controls. PBMCs were incubated for 18 h at 37°C under 5% CO2 in RPMI-1640 containing 10% (v/v) serum from healthy blood group AB donors, either alone or stimulated with 10 µg/ml CpG oligodeoxynucleotides. Expression of the cell-surface markers CD5, CD27, CD25 and CD19, and intracellular content of IL-6 and IL-10 were measured by flow cytometry. Results All patients responded to therapy and were in complete or partial remission at 12 months. Patient characteristics are listed in table I. We observed a significant increase in the proportion of CD5+ B cells 12 months after treatment with RTX+DXM compared to baseline (p < 0.01, Fig. 1A). The percentage of CD27+ memory B cells was significantly decreased at 12 months compared to baseline in patients receiving RTX+DXM (p < 0.05, Fig. 1B), and there was an inverse correlation between platelet numbers and the proportion of CD27+ B cells (R = -0.71; p < 0.05). The proportion of CD25+ B cells tended to decrease in patients treated with RTX+DXM, and was lower at 12 months than in patients treated with DMX only (p < 0.05, Fig 1C). PBMCs from ITP patients contained a lower proportion of IL-10+ B cells (p < 0.01) as well as a lower proportion of B cells producing IL-6 (p < 0.01) at baseline than PBMCs from healthy controls. At 12 months the low proportions had normalized in both treatment groups (Fig. 2). Conclusion B cells from ITP patients treated with RTX+DXM contained a high proportion of CD5+ B cells and low proportions of CD25+ and CD27+ B cells. Before treatment, B cells from ITP patients contained low frequencies of IL-10+ and IL-6+ B cells. Treatment with RTX + DXM or DXM alone reverted these aberrancies to normal. The increase in IL-10+ B cells as well as CD5+ B cells, which may represent overlapping subsets, is compatible with induction of Bregs and may support Treg development. Given the role of CD5+ B cells in maintenance of tolerance, the high frequency of these cells, which has also been observed after RTX therapy in rheumatoid arthritis, is compatible with amelioration of disease. Table 1 Table 1. Disclosures Gudbrandsdottir: GSK: Research Funding; Amgen: Research Funding.

scholarly journals Multiscale Modeling of Germinal Center Recapitulates the Temporal Transition From Memory B Cells to Plasma Cells Differentiation as Regulated by Antigen Affinity-Based Tfh Cell Help

2021 ◽  
Vol 11 ◽  
Author(s):  
Elena Merino Tejero ◽  
Danial Lashgari ◽  
Rodrigo García-Valiente ◽  
Xuefeng Gao ◽  
Fabien Crauste ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Fate ◽  
Plasma Cell ◽  
Germinal Center ◽  
Plasma Cells ◽  
Asymmetric Division ◽  
Memory B Cells ◽  
Memory B Cell ◽  
Germinal Center Reaction

Germinal centers play a key role in the adaptive immune system since they are able to produce memory B cells and plasma cells that produce high affinity antibodies for an effective immune protection. The mechanisms underlying cell-fate decisions are not well understood but asymmetric division of antigen, B-cell receptor affinity, interactions between B-cells and T follicular helper cells (triggering CD40 signaling), and regulatory interactions of transcription factors have all been proposed to play a role. In addition, a temporal switch from memory B-cell to plasma cell differentiation during the germinal center reaction has been shown. To investigate if antigen affinity-based Tfh cell help recapitulates the temporal switch we implemented a multiscale model that integrates cellular interactions with a core gene regulatory network comprising BCL6, IRF4, and BLIMP1. Using this model we show that affinity-based CD40 signaling in combination with asymmetric division of B-cells result in switch from memory B-cell to plasma cell generation during the course of the germinal center reaction. We also show that cell fate division is unlikely to be (solely) based on asymmetric division of Ag but that BLIMP1 is a more important factor. Altogether, our model enables to test the influence of molecular modulations of the CD40 signaling pathway on the production of germinal center output cells.

scholarly journals Memory persistence and differentiation into antibody-secreting cells accompanied by positive selection in longitudinal BCR repertoires

2022 ◽  
Author(s):  
Artem I. Mikelov ◽  
Evgeniia I. Alekseeva ◽  
Ekaterina A. Komech ◽  
Dmitriy B. Staroverov ◽  
Maria A. Turchaninova ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Peripheral Blood ◽  
Plasma Cells ◽  
Inflammatory Diseases ◽  
Affinity Maturation ◽  
Memory B Cells ◽  
Immune Memory ◽  
Memory B Cell ◽  
Antibody Secreting Cells

B-cell mediated immune memory holds both plasticity and conservatism to respond to new challenges and repeated infections. Here, we analyze the dynamics of immunoglobulin heavy chain (IGH) repertoires of memory B cells, plasmablasts and plasma cells sampled several times during one year from peripheral blood of volunteers without severe inflammatory diseases. We reveal a high degree of clonal persistence in individual memory B-cell subsets with inter-individual convergence in memory and antibody-secreting cells (ASCs). Clonotypes in ASCs demonstrate clonal relatedness to memory B cells and are transient in peripheral blood. Two clusters of expanded clonal lineages displayed different prevalence of memory B cells, isotypes, and persistence. Phylogenetic analysis revealed signs of reactivation of persisting memory B cell-enriched clonal lineages, accompanied by new rounds of affinity maturation during proliferation to ASCs. Negative selection contributes to both, persisting and reactivated lineages, saving functionality and specificity of BCRs to protect from the current and future pathogens.

scholarly journals Distinct clonal evolution of B-cells in HIV controllers with neutralizing antibody breadth

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Deniz Cizmeci ◽  
Giuseppe Lofano ◽  
Evan Rossignol ◽  
Anne-Sophie Dugast ◽  
Dongkyoon Kim ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Somatic Hypermutation ◽  
Clonal Evolution ◽  
Neutralizing Antibody ◽  
Affinity Maturation ◽  
Gene Repertoire ◽  
Immunoglobulin Gene ◽  
Hiv Controllers ◽  
Hiv 1

A minor subset of individuals infected with HIV-1 develop antibody neutralization breadth during the natural course of the infection, often linked to chronic, high-level viremia. Despite significant efforts, vaccination strategies have been unable to induce similar neutralization breadth and the mechanisms underlying neutralizing antibody induction remain largely elusive. Broadly neutralizing antibody responses can also be found in individuals who control HIV to low and even undetectable plasma levels in the absence of antiretroviral therapy, suggesting that high antigen exposure is not a strict requirement for neutralization breadth. We therefore performed an analysis of paired heavy and light chain B-cell receptor (BCR) repertoires in 12,591 HIV-1 envelope-specific single memory B-cells to determine alterations in the BCR immunoglobulin gene repertoire and B-cell clonal expansions that associate with neutralizing antibody breadth in 22 HIV controllers. We found that the frequency of genomic mutations in IGHV and IGLV was directly correlated with serum neutralization breadth. The repertoire of the most mutated antibodies was dominated by a small number of large clones with evolutionary signatures suggesting that these clones had reached peak affinity maturation. These data demonstrate that even in the setting of low plasma HIV antigenemia, similar to what a vaccine can potentially achieve, BCR selection for extended somatic hypermutation and clonal evolution can occur in some individuals suggesting that host-specific factors might be involved that could be targeted with future vaccine strategies.

MO251HIGHLY SENSITIVE FLOW CYTOMETRIC DETECTION OF RESIDUAL B-CELLS AFTER RITUXIMAB IN ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY-ASSOCIATED VASCULITIS PATIENTS*

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Y K O Teng ◽  
L Van Dam ◽  
Jelle Oskam ◽  
S W A Kamerling ◽  
E J Arends ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
B Cells ◽  
B Cell ◽  
Mononuclear Cells ◽  
Plasma Cells ◽  
Memory B Cells ◽  
Cell Depletion ◽  
B Cell Depletion ◽  
Peripheral Blood Mononuclear

Abstract Background and Aims B-cell depletion with rituximab (RTX) is an effective treatment for anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) patients. Nevertheless, relapses are frequent after RTX, often preceded by B-cell repopulation suggesting that residual autoreactive B-cells persist despite therapy. Therefore, this study aimed to identify minimal residual autoimmunity (MRA) in the B-cell compartment of AAV patients treated with RTX. Method EuroFlow-based highly-sensitive flow cytometry (HSFC) was employed to study B-cell and plasma cell (PC) subsets in-depth in AAV patients before and after RTX treatment. Additionally, peripheral blood mononuclear cells (PBMCs) of these RTX-treated AAV patients were cultured and in vitro stimulated with CpG, IL-2, and IL-21 to induce antibody-secreting cells (ASC). (ANCA)-IgG was measured in these supernatants by ELISA. Results By employing EuroFlow-based HSFC, we detected circulating CD19+ B-cells at all timepoints after RTX treatment, in contrast to conventional low-sensitive flow cytometry. Pre-germinal center (Pre-GC) B-cells, memory B-cells and CD20+CD138− plasmablasts (PBs) were rapidly and strongly reduced, while CD20−CD138− PrePC and CD20-CD138+ mature (m)PCs were reduced slower and remained detectable. Both memory B-cells and CD20− PCs remained detectable after RTX. Serum ANCA-IgG decreased significantly upon RTX. Changes in ANCA levels strongly correlated with changes in naive, switched CD27+ and CD27− (double-negative) memory B-cells, but not with plasma cells. Lastly, we demonstrated in vitro ANCA production by AAV PBMCs, 24 and 48 weeks after RTX treatment reflecting MRA in the memory compartment of AAV patients. Conclusion We demonstrated that RTX induced strong reductions in circulating B-cells, but never resulted in complete B-cell depletion. Despite strongly reduced B-cell numbers after RTX, ANCA-specific memory B-cells were still detectable in AAV patients. Thus, MRA is identifiable in AAV and can provide a potential novel approach in personalizing RTX treatment in AAV patients.

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