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[This corrects the article DOI: 10.3389/fimmu.2024.1391404.].
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Introduction: Follicular Lymphoma (FL) results from the malignant transformation of germinal center (GC) B cells. FL B cells display recurrent and diverse genetic alterations, some of them favoring their direct interaction with their cell microenvironment, including follicular helper T cells (Tfh). Although FL-Tfh key role is well-documented, the impact of their regulatory counterpart, the follicular regulatory T cell (Tfr) compartment, is still sparse. Methods: The aim of this study was to characterize FL-Tfr phenotype by cytometry, gene expression profile, FL-Tfr origin by transcriptomic analysis, and functionality by in vitro assays. Results: CD4+CXCR5+CD25hiICOS+ FL-Tfr displayed a regulatory program that is close to classical regulatory T cell (Treg) program, at the transcriptomic and methylome levels. Accordingly, Tfr imprinting stigmata were found on FL-Tfh and FL-B cells, compared to their physiological counterparts. In addition, FL-Tfr co-culture with autologous FL-Tfh or cytotoxic FL-CD8+ T cells inhibited their proliferation in vitro. Finally, although FL-Tfr shared many characteristics with Treg, TCR sequencing analyses demonstrated that part of them derived from precursors shared with FL-Tfh. Discussion: Altogether, these findings uncover the role and origin of a Tfr subset in FL niche and may be useful for lymphomagenesis knowledge and therapeutic management.
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Linfoma Folicular , Linfocitos T Reguladores , Linfoma Folicular/inmunología , Linfoma Folicular/genética , Linfoma Folicular/patología , Humanos , Linfocitos T Reguladores/inmunología , Perfilación de la Expresión Génica , Transcriptoma , Microambiente Tumoral/inmunología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Células T Auxiliares Foliculares/inmunología , Células T Auxiliares Foliculares/metabolismo , Masculino , Femenino , Técnicas de Cocultivo , Centro Germinal/inmunologíaRESUMEN
PURPOSE: This study aims to investigate the relationship between the intensity of the initial treatment given to patients with de novo diffuse large B-cell lymphoma (DLBCL) and the impact of their baseline cell-free DNA (cfDNA) levels on their long-term survival. EXPERIMENTAL DESIGN: The GOELAMS 075 randomized clinical trial compared rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) with high-dose R-chemotherapy plus autologous stem cell transplantation (R-HDT) for patients aged ≤60. An interim PET assessment was used to refer patients for salvage therapy. With a median follow-up of more than 5.8 years, we analyzed the effects of the treatment arm, salvage therapy, and cfDNA level at diagnosis on overall survival (OS). RESULTS: In a representative group of 123 patients, a high cfDNA concentration (>55 ng/mL) at diagnosis was associated with poor clinical prognostic factors and constituted a prognostic marker, independently of the age-adjusted International Prognostic Index. A cfDNA level above a threshold value of 55 ng/mL at diagnosis was associated with significantly worse OS. In an intention-to-treat analysis, high-cfDNA R-CHOP patients (but not high-cfDNA R-HDT patients) had worse OS [HR (95% confidence interval), 3.99 (1.98-10.74); P = 0.006]. In patients with high cfDNA levels, salvage therapy and transplantation were associated with a significantly higher OS rate. Among 50 patients with complete response 6 months after the end of treatment, for 11 of 24 R-CHOP patients, the cfDNA did not fall back to normal values. CONCLUSIONS: In this randomized clinical trial, intensive regimens mitigated the negative influence of high cfDNA levels in de novo DLBCL, relative to R-CHOP.
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Ácidos Nucleicos Libres de Células , Trasplante de Células Madre Hematopoyéticas , Linfoma de Células B Grandes Difuso , Humanos , Anticuerpos Monoclonales de Origen Murino/uso terapéutico , Supervivencia sin Enfermedad , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Trasplante Autólogo , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Rituximab/uso terapéutico , Vincristina , Doxorrubicina , CiclofosfamidaRESUMEN
Non-Hodgkin B-cell lymphomas (B-NHL) mainly develop within lymph nodes as aggregates of tumor cells densely packed with their surrounding microenvironment, creating a tumor niche specific to each lymphoma subtypes. In vitro preclinical models mimicking biomechanical forces, cellular microenvironment, and 3D organization of B-cell lymphomas remain scarce, while all these parameters are key determinants of lymphomagenesis and drug resistance. Using a microfluidic method based on cell encapsulation inside permeable, elastic, and hollow alginate microspheres, we developed a new tunable 3D model incorporating lymphoma B cells, extracellular matrix (ECM), and/or tonsil stromal cells (TSC). Under 3D confinement, lymphoma B cells were able to form cohesive spheroids resulting from overexpression of ECM components. Moreover, lymphoma B cells and TSC dynamically formed self-organized 3D spheroids favoring tumor cell growth. 3D culture induced resistance to the classical chemotherapeutic agent doxorubicin, but not to the BCL2 inhibitor ABT-199, identifying this approach as a relevant in vitro model to assess the activity of therapeutic agents in B-NHL. RNA-sequence analysis highlighted the synergy of 3D, ECM, and TSC in upregulating similar pathways in malignant B cells in vitro than those overexpressed in primary lymphoma B cells in situ. Finally, our 3D model including ECM and TSC allowed long-term in vitro survival of primary follicular lymphoma B cells. In conclusion, we propose a new high-throughput 3D model mimicking lymphoma tumor niche and making it possible to study the dynamic relationship between lymphoma B cells and their microenvironment and to screen new anti-cancer drugs.
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Antineoplásicos , Linfoma de Células B , Linfoma no Hodgkin , Linfocitos B , Proliferación Celular , Humanos , Linfoma de Células B/tratamiento farmacológico , Microambiente TumoralRESUMEN
Lymphoid stromal cells (LSCs) are essential organizers of immune responses. We analyzed tonsillar tissue by combining flow cytometry, in situ imaging, RNA sequencing, and functional assays, defining three distinct human LSC subsets. The integrin CD49a designated perivascular stromal cells exhibiting features of local committed LSC precursors and segregated cytokine and chemokine-producing fibroblastic reticular cells (FRCs) supporting B and T cell survival. The follicular dendritic cell transcriptional profile reflected active responses to B cell and non-B cell stimuli. We therefore examined the effect of B cell stimuli on LSCs in follicular lymphoma (FL). FL B cells interacted primarily with CD49a+ FRCs. Transcriptional analyses revealed LSC reprogramming in situ downstream of the cytokines tumor necrosis factor (TNF) and transforming growth factor ß (TGF-ß), including increased expression of the chemokines CCL19 and CCL21. Our findings define human LSC populations in healthy tissue and reveal bidirectional crosstalk between LSCs and malignant B cells that may present a targetable axis in lymphoma.
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Linfocitos B/inmunología , Células Dendríticas/inmunología , Linfoma Folicular/inmunología , Linfoma Folicular/patología , Tonsila Palatina/inmunología , Células del Estroma/inmunología , Células Cultivadas , Quimiocina CCL19/metabolismo , Quimiocina CCL21/metabolismo , Humanos , Integrina alfa1/metabolismo , Tonsila Palatina/citología , Transducción de Señal/inmunología , Células del Estroma/citología , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Follicular lymphoma (FL) originates in the lymph nodes (LNs) and infiltrates bone marrow (BM) early in the course of the disease. BM FL B cells are characterized by a lower cytological grade, decreased proliferation, and a specific phenotypic and subclonal profile. Mesenchymal stromal cells (MSCs) obtained from FL BM display a specific gene expression profile (GEP), including enrichment for a lymphoid stromal cell signature, and an increased capacity to sustain FL B-cell growth. However, the mechanisms triggering the formation of the medullar FL permissive stromal niche have not been identified. In the current work, we demonstrate that FL B cells produce extracellular vesicles (EVs) that can be internalized by BM-MSCs, making them more efficient to support FL B-cell survival and quiescence. Accordingly, EVs purified from FL BM plasma activate transforming growth factor ß-dependent and independent pathways in BM-MSCs and modify their GEP, triggering an upregulation of factors classically associated with hematopoietic stem cell niche, including CXCL12 and angiopoietin-1. Moreover, we provide the first characterization of BM FL B-cell GEP, allowing the definition of the landscape of molecular interactions they could engage with EV-primed BM-MSCs. This work identifies FL-derived EVs as putative mediators of BM stroma polarization and supports further investigation of their clinical interest for targeting the crosstalk between BM-MSCs and malignant B cells.
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Linfocitos B/patología , Células de la Médula Ósea/patología , Polaridad Celular , Vesículas Extracelulares/patología , Linfoma Folicular/patología , Secuencia de Bases , Células de la Médula Ósea/metabolismo , Comunicación Celular , Diferenciación Celular , Endocitosis , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/ultraestructura , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Células Madre Hematopoyéticas/metabolismo , Humanos , Linfoma Folicular/genética , Heterotrímero de Linfotoxina alfa1 y beta2/metabolismo , Células Madre Mesenquimatosas/metabolismo , Fenotipo , Transducción de Señal , Células del Estroma/metabolismo , Células del Estroma/patología , Factor de Necrosis Tumoral alfa/metabolismo , Regulación hacia Arriba/genéticaRESUMEN
In diffuse large B-cell lymphoma (DLBCL), tumor-infiltrating T lymphocytes (TILs) are involved in therapeutic responses. However, tumor-specific TILs can be dysfunctional, with impaired effector functions. Various mechanisms are involved in this exhaustion, and the increased expression of programmed cell death receptor 1 (PD1) and TIM3 on dysfunctional cells suggests their involvement. However, conflicting data have been published regarding their expression or coexpression in DLBCL. We evaluated the presence and phenotype of CD4+ and CD8+ TILs in freshly collected tumor tissues in DLBCL and compared the results with those in follicular lymphoma, classical Hodgkin lymphoma, and nonmalignant reactive lymphadenopathy. We found that TILs expressing both PD1 and TIM3 were expanded in DLBCL, particularly in the activated B cell-like subgroup. Isolated PD1+TIM3+ TILs exhibited a transcriptomic signature related to T-cell exhaustion associated with a reduction in cytokine production, both compromising the antitumor immune response. However, these cells expressed high levels of cytotoxic molecules. In line with this, stimulated PD1+TIM3+ TILs from DLBCL patients exhibited reduced proliferation and impaired secretion of interferon-γ, but these functions were restored by the blockade of PD1 or TIM3. In summary, the PD1+TIM3+ TIL population is expanded and exhausted in DLBCL but can be reinvigorated with appropriate therapies.
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Receptor 2 Celular del Virus de la Hepatitis A , Linfoma de Células B Grandes Difuso , Linfocitos T CD8-positivos , Receptor 2 Celular del Virus de la Hepatitis A/genética , Humanos , Linfocitos Infiltrantes de Tumor , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Receptor de Muerte Celular Programada 1/genéticaRESUMEN
Distinguishing chronic lymphoproliferative disorders of NK cells (CLPD-NK) from reactive NK-cell expansion is challenging. We assessed the value of killer immunoglobulin-like receptor(KIR) phenotyping and targeted high-throughput sequencing in a cohort of 114 consecutive patients with NK cell proliferation, retrospectively assigned to a CLPD-NK group (n = 46) and a reactive NK group (n = 68). We then developed an NK-cell clonality score combining flow cytometry and molecular profiling with a positive predictive value of 93%. STAT3 and TET2 mutations were respectively identified in 27% and 34% of the patients with CLPD-NK, constituting a new diagnostic hallmark for this disease. TET2-mutated CLPD-NK preferentially exhibited a CD16low phenotype, more frequently displayed a lower platelet count, and was associated with other hematologic malignancies such as myelodysplasia. To explore the mutational clonal hierarchy of CLPD-NK, we performed whole-exome sequencing of sorted, myeloid, T, and NK cells and found that TET2 mutations were shared by myeloid and NK cells in 3 of 4 cases. Thus, we hypothesized that TET2 alterations occur in early hematopoietic progenitors which could explain a potential link between CLPD-NK and myeloid malignancies. Finally, we analyzed the transcriptome by RNA sequencing of 7 CLPD-NK and evidenced 2 groups of patients. The first group displayed STAT3 mutations or SOCS3 methylation and overexpressed STAT3 target genes. The second group, including 2 TET2-mutated cases, significantly underexpressed genes known to be downregulated in angioimmunoblastic T-cell lymphoma. Our results provide new insights into the pathogenesis of NK-cell proliferative disorders and, potentially, new therapeutic opportunities.
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Proteínas de Unión al ADN/metabolismo , Dioxigenasas/metabolismo , Células Asesinas Naturales/metabolismo , Linfoma de Células T/metabolismo , Mutación , Proteínas de Neoplasias/metabolismo , Receptores KIR/metabolismo , Factor de Transcripción STAT3/metabolismo , Anciano , Enfermedad Crónica , Proteínas de Unión al ADN/genética , Dioxigenasas/genética , Femenino , Células Madre Hematopoyéticas/metabolismo , Humanos , Linfoma de Células T/genética , Masculino , Persona de Mediana Edad , Proteínas de Neoplasias/genética , Receptores KIR/genética , Factor de Transcripción STAT3/genéticaRESUMEN
Absolute count of circulating monocytes has been proposed as an independent prognostic factor in diffuse large B-cell lymphoma (DLBCL). However, monocyte nomenclature includes various subsets with pro-, anti-inflammatory, or suppressive functions, and their clinical relevance in DLBCL has been poorly explored. Herein, we broadly assessed circulating monocyte heterogeneity in 91 DLBCL patients. Classical- (cMO, CD14pos CD16neg) and intermediate- (iMO, CD14pos CD16pos) monocytes accumulated in DLBCL peripheral blood and exhibited an inflammatory phenotype. On the opposite, nonclassical monocytes (ncMOSlanpos, CD14low CD16pos Slanneg and ncMOSlanneg, CD14low CD16pos, Slanneg) were decreased in peripheral blood. Tumor-conditioned monocytes presented similarities with ncMO phenotype from DLBCL and were prone to migrate in response to CCL5 and CXCL12, and presented similarities with DLBCL-infiltrated myeloid cells, as defined by mass cytometry. Finally, we demonstrated the adverse value of an accumulation of nonclassical monocytes in 2 independent cohorts of DLBCL.
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Linfoma de Células B Grandes Difuso/inmunología , Linfoma de Células B Grandes Difuso/patología , Monocitos/inmunología , Monocitos/patología , Adulto , Anciano , Femenino , Humanos , Inmunofenotipificación , Masculino , Persona de Mediana EdadRESUMEN
Follicular lymphoma (FL), the most frequent indolent non-Hodgkin's B cell lymphoma, is considered as a prototypical centrocyte-derived lymphoma, dependent on a specific microenvironment mimicking the normal germinal center (GC). In agreement, several FL genetic alterations affect the crosstalk between malignant B cells and surrounding cells, including stromal cells and follicular helper T cells (Tfh). In our study, we sought to deconvolute this complex FL supportive synapse by comparing the transcriptomic profiles of GC B cells, Tfh, and stromal cells, isolated from normal versus FL tissues, in order to identify tumor-specific pathways. In particular, we highlighted a high expression of IL-6 and IL-7 in FL B cells that could favor the activation of FL Tfh overexpressing IFNG, able in turn to stimulate FL B cells without triggering MHC (major histocompatibility) class II expression. Moreover, the glycoprotein clusterin was found up-regulated in FL stromal cells and could promote FL B cell adhesion. Finally, besides its expression on Tfh, CD200 was found overexpressed on tumor B cells and could contribute to the induction of the immunosuppressive enzyme indoleamine-2,3 dioxygenase by CD200R-expressing dendritic cells. Altogether our findings led us to outline the contribution of major signals provided by the FL microenvironment and their interactions with malignant FL B cells.
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Clinical-grade mesenchymal stromal cells (MSCs) can be expanded from bone marrow and adipose tissue to treat inflammatory diseases and degenerative disorders. However, the influence of their tissue of origin on their functional properties, including their immunosuppressive activity, remains unsolved. In this study, we produced paired bone marrow-derived mesenchymal stromal cell (BM-MSC) and adipose-derived stromal cell (ASC) batches from 14 healthy donors. We then compared them using transcriptomic, phenotypic, and functional analyses and validated our results on purified native MSCs to infer which differences were really endowed by tissue of origin. Cultured MSCs segregated together owing to their tissue of origin based on their gene expression profile analyzed using differential expression and weighted gene coexpression network analysis. This translated into distinct immune-related gene signatures, phenotypes, and functional cell interactions. Importantly, sorted native BM-MSCs and ASCs essentially displayed the same distinctive patterns than their in vitro-expanded counterparts. As a whole, ASCs exhibited an immune profile consistent with a stronger inhibition of immune response and a lower immunogenicity, supporting the use of adipose tissue as a valuable source for clinical applications.
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Células Madre Mesenquimatosas/metabolismo , Transcriptoma/genética , Adulto , Diferenciación Celular , Células Cultivadas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fenotipo , Adulto JovenRESUMEN
In the original version of this article the authors noted an omission in the author affiliations where the university details: Queen Mary University of London was not included in the original affiliation for the majority of the authors. The correct affiliations are as follows1. Centre for Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK3. Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK6. Evolution and Cancer Laboratory, Barts Cancer Institute, Queen Mary University of London, London, UK.
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PURPOSE: Follicular lymphoma arises from a germinal center B-cell proliferation supported by a bidirectional crosstalk with tumor microenvironment, in particular with follicular helper T cells (Tfh). We explored the relation that exists between the differentiation arrest of follicular lymphoma cells and loss-of-function of CREBBP acetyltransferase.Experimental Design: The study used human primary cells obtained from either follicular lymphoma tumors characterized for somatic mutations, or inflamed tonsils for normal germinal center B cells. Transcriptome and functional analyses were done to decipher the B- and T-cell crosstalk. Responses were assessed by flow cytometry and molecular biology including ChIP-qPCR approaches. RESULTS: Conversely to normal B cells, follicular lymphoma cells are unable to upregulate the transcription repressor, PRDM1, required for plasma cell differentiation. This defect occurs although the follicular lymphoma microenvironment is enriched in the potent inducer of PRDM1 and IL21, highly produced by Tfhs. In follicular lymphoma carrying CREBBP loss-of-function mutations, we found a lack of IL21-mediated PRDM1 response associated with an abnormal increased enrichment of the BCL6 protein repressor in PRDM1 gene. Moreover, in these follicular lymphoma cells, pan-HDAC inhibitor, vorinostat, restored their PRDM1 response to IL21 by lowering BCL6 bound to PRDM1. This finding was reinforced by our exploration of patients with follicular lymphoma treated with another pan-HDAC inhibitor. Patients showed an increase of plasma cell identity genes, mainly PRDM1 and XBP1, which underline the progression of follicular lymphoma B cells in the differentiation process. CONCLUSIONS: Our data uncover a new mechanism by which pan-HDAC inhibitors may act positively to treat patients with follicular lymphoma through the induction of the expression of plasma cell genes.
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Proteína de Unión a CREB/genética , Inhibidores de Histona Desacetilasas/farmacología , Interleucinas/metabolismo , Linfoma Folicular/genética , Linfoma Folicular/metabolismo , Mutación , Factor 1 de Unión al Dominio 1 de Regulación Positiva/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Proteína de Unión a CREB/metabolismo , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Centro Germinal/metabolismo , Centro Germinal/patología , Inhibidores de Histona Desacetilasas/uso terapéutico , Humanos , Interleucinas/farmacología , Linfoma Folicular/tratamiento farmacológico , Linfoma Folicular/patología , Modelos Biológicos , Clasificación del Tumor , Células Plasmáticas/metabolismo , Células Plasmáticas/patología , Unión Proteica , Proteínas Proto-Oncogénicas c-bcl-6/metabolismo , Factor de Transcripción STAT3/metabolismo , TranscriptomaRESUMEN
Activated B-cell diffuse large B-cell lymphoma (ABC-DLBCL) is an aggressive lymphoproliferative disorder involving chronic NF-κB activation. Several mutations in the BCR and MyD88 signaling pathway components, such as MyD88 L265P, are implicated in this aberrant activation. Among heat shock proteins, HSP110 has recently been identified as a prosurvival and/or proliferation factor in many cancers, but its role in ABC-DLBCL survival mechanisms remained to be established. We observed that short hairpin RNA-mediated HSP110 silencing decreased the survival of several ABC-DLBCL cell lines and decreased immunoglobulin M-MyD88 co-localization and subsequent NF-κB signaling. Conversely, overexpression of HSP110 in ABC-DLBCL or non-DLBCL cell lines increased NF-κB signaling, indicating a tight interplay between HSP110 and the NF-κB pathway. By using immunoprecipitation and proximity ligation assays, we identified an interaction between HSP110 and both wild-type MyD88 and MyD88 L265P. HSP110 stabilized both MyD88 forms with a stronger effect on MyD88 L265P, thus facilitating chronic NF-κB activation. Finally, HSP110 expression was higher in lymph node biopsies from patients with ABC-DLBCL than in normal reactive lymph nodes, and a strong correlation was found between the level of HSP110 and MyD88. In conclusion, we identified HSP110 as a regulator of NF-κB signaling through MyD88 stabilization in ABC-DLBCL. This finding reveals HSP110 as a new potential therapeutic target in ABC-DLBCL.
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Proteínas del Choque Térmico HSP110/metabolismo , Linfoma de Células B Grandes Difuso/patología , Factor 88 de Diferenciación Mieloide/química , FN-kappa B/metabolismo , Estudios de Cohortes , Proteínas del Choque Térmico HSP110/genética , Humanos , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/metabolismo , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/metabolismo , FN-kappa B/genética , Estabilidad Proteica , Transducción de Señal , Células Tumorales CultivadasAsunto(s)
Reordenamiento Génico , Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Glicoproteína Asociada a Mielina/inmunología , Factor 88 de Diferenciación Mieloide/genética , Paraproteinemias/genética , Enfermedades del Sistema Nervioso Periférico/genética , Receptores CXCR4/genética , Anciano , Autoanticuerpos/sangre , Autoanticuerpos/inmunología , Estudios de Casos y Controles , Femenino , Humanos , Inmunoglobulina M , Masculino , Persona de Mediana Edad , Mutación , Paraproteinemias/patología , Enfermedades del Sistema Nervioso Periférico/patología , PronósticoRESUMEN
RATIONALE: Sepsis induces a sustained immune dysfunction responsible for poor outcome and nosocomial infections. Myeloid-derived suppressor cells (MDSCs) described in cancer and inflammatory processes may be involved in sepsis-induced immune suppression, but their clinical impact remains poorly defined. OBJECTIVES: To clarify phenotype, suppressive activity, origin, and clinical impact of MDSCs in patients with sepsis. METHODS: Peripheral blood transcriptomic analysis was performed on 29 patients with sepsis and 15 healthy donors. A second cohort of 94 consecutive patients with sepsis, 11 severity-matched intensive care patients, and 67 healthy donors was prospectively enrolled for flow cytometry and functional experiments. MEASUREMENTS AND MAIN RESULTS: Genes involved in MDSC suppressive functions, including S100A12, S100A9, MMP8, and ARG1, were up-regulated in the peripheral blood of patients with sepsis. CD14posHLA-DRlow/neg monocytic (M)-MDSCs were expanded in intensive care unit patients with and without sepsis and CD14negCD15pos low-density granulocytes/granulocytic (G)-MDSCs were more specifically expanded in patients with sepsis (P < 0.001). Plasma levels of MDSC mediators S100A8/A9, S100A12, and arginase 1 were significantly increased. In vitro, CD14pos- and CD15pos-cell depletion increased T-cell proliferation in patients with sepsis. G-MDSCs, made of immature and mature granulocytes expressing high levels of degranulation markers, were specifically responsible for arginase 1 activity. High initial levels of G-MDSCs, arginase 1, and S100A12 but not M-MDSCs were associated with subsequent occurrence of nosocomial infections. CONCLUSIONS: M-MDSCs and G-MDSCs strongly contribute to T-cell dysfunction in patients with sepsis. More specifically, G-MDSCs producing arginase 1 are associated with a higher incidence of nosocomial infections and seem to be major actors of sepsis-induced immune suppression.
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Infección Hospitalaria/inmunología , Células Supresoras de Origen Mieloide/inmunología , Sepsis/inmunología , Adulto , Anciano , Proliferación Celular , Infección Hospitalaria/sangre , Femenino , Citometría de Flujo , Granulocitos/inmunología , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sepsis/sangreRESUMEN
Follicular lymphoma (FL) is the most frequent indolent lymphoma and is characterized by the accumulation of germinal center-derived malignant B cells engaged in a bidirectional crosstalk with their supportive microenvironment in invaded lymph nodes (LNs) and bone marrow (BM). T follicular helper (TFH) cells and infiltrating stromal cells have been shown to favor FL B-cell growth, but the mechanisms of their protumoral effect and how the LN/BM microenvironment is converted into a lymphoma-permissive cell niche remain poorly understood. We demonstrated here that FL-infiltrating LN and BM stromal cells overexpressed CXCL12 in situ. Interleukin-4 high (IL-4hi) FL-TFH cells, unlike FL B cells themselves, triggered CXCL12 upregulation in human stromal cell precursors. In agreement, expression of CXCL12 was associated with IL-4 expression and signaling within the FL BM and LN niches. This IL-4/CXCL12 axis was amplified in activated lymphoid stromal cells as shown in our in vitro model of human lymphoid stroma differentiation and in an inducible mouse model of ectopic lymphoid organ formation. Finally, CXCL12 triggered primary FL B-cell activation, migration, and adhesion, a process antagonized by BTK and PI3K inhibitors. These data identified the IL-4/CXCL12 loop as a previously unrecognized pathway involved in lymphoid stroma polarization and as a potential therapeutic target in FL patients.
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Médula Ósea/inmunología , Quimiocina CXCL12/inmunología , Interleucina-4/inmunología , Ganglios Linfáticos/inmunología , Linfoma Folicular/inmunología , Transducción de Señal/inmunología , Animales , Linfocitos B/inmunología , Linfocitos B/patología , Médula Ósea/patología , Movimiento Celular/genética , Movimiento Celular/inmunología , Quimiocina CXCL12/genética , Femenino , Humanos , Interleucina-4/genética , Ganglios Linfáticos/patología , Linfoma Folicular/genética , Linfoma Folicular/patología , Masculino , Ratones , Ratones Noqueados , Transducción de Señal/genética , Células del Estroma/inmunología , Células del Estroma/patología , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/patologíaRESUMEN
In diffuse large B-cell lymphoma (DLBCL), the number of circulating monocytes and neutrophils represents an independent prognostic factor. These cell subsets include monocytic and granulocytic myeloid-derived suppressor cells (M- and G-MDSCs) defined by their ability to suppress T-cell responses. MDSCs are a heterogeneous population described in inflammatory and infectious diseases and in numerous tumors including multiple myeloma, chronic lymphocytic leukemia, and DLBCL. However, their mechanisms of action remain unclear. We broadly assessed the presence and mechanisms of suppression of MDSC subsets in DLBCL. First, a myeloid suppressive signature was identified by gene expression profiling in DLBCL peripheral blood. Accordingly, we identified, in a cohort of 66 DLBCL patients, an increase in circulating G-MDSC (Lin(neg)HLA-DR(neg)CD33(pos)CD11b(pos)) and M-MDSC (CD14(pos)HLA-DR(low)) counts. Interestingly, only M-MDSC number was correlated with the International Prognostic Index, event-free survival, and number of circulating Tregs. Furthermore, T-cell proliferation was restored after monocyte depletion. Myeloid-dependent T-cell suppression was attributed to a release of interleukin-10 and S100A12 and increased PD-L1 expression. In summary, we identified expanded MDSC subsets in DLBCL, as well as new mechanisms of immunosuppression in DLBCL.