TRAF3 loss-of-function reveals the noncanonical NF-κB pathway as a therapeutic target in diffuse large B cell lymphoma.

Here, we report recurrent focal deletions of the chr14q32.31-32 locus, including TRAF3, a negative regulator of NF-κB signaling, in de novo diffuse large B cell lymphoma (DLBCL) (24/324 cases). Integrative analysis revealed an association between TRAF3 copy number loss with accumulation of NIK, the central noncanonical (NC) NF-κB kinase, and increased NC NF-κB pathway activity. Accordingly, TRAF3 genetic ablation in isogenic DLBCL model systems caused upregulation of NIK and enhanced NC NF-κB downstream signaling. Knockdown or pharmacological inhibition of NIK in TRAF3-deficient cells differentially impaired their proliferation and survival, suggesting an acquired onco-addiction to NC NF-κB. TRAF3 ablation also led to exacerbated secretion of the immunosuppressive cytokine IL-10. Coculturing of TRAF3-deficient DLBCL cells with CD8+ T cells impaired the induction of Granzyme B and interferon (IFN) γ, which were restored following neutralization of IL-10. Our findings corroborate a direct relationship between TRAF3 genetic alterations and NC NF-κB activation, and highlight NIK as a potential therapeutic target in a defined subset of DLBCL.

Characterization of DLBCL with a PMBL gene expression signature.

Primary mediastinal large B-cell lymphoma (PMBL) is a type of aggressive B-cell lymphoma that typically affects young adults, characterized by presence of a bulky anterior mediastinal mass. Lymphomas with gene expression features of PMBL have been described in nonmediastinal sites, raising questions about how these tumors should be classified. Here, we investigated whether these nonmediastinal lymphomas are indeed PMBLs or instead represent a distinct group within diffuse large B-cell lymphoma (DLBCL). From a cohort of 325 de novo DLBCL cases, we identified tumors from patients without evidence of anterior mediastinal involvement that expressed a PMBL expression signature (nm-PMBLsig+; n = 16; 5%). A majority of these tumors expressed MAL and CD23, proteins typically observed in bona fide PMBL (bf-PMBL). Evaluation of clinical features of nm-PMBLsig+ cases revealed close associations with DLBCL, and a majority displayed a germinal center B cell-like cell of origin (GCB). In contrast to patients with bf-PMBL, patients with nm-PMBLsig+ presented at an older age and did not show pleural disease, and bone/bone marrow involvement was observed in 3 cases. However, although clinically distinct from bf-PMBL, nm-PMBLsig+ tumors resembled bf-PMBL at the molecular level, with upregulation of immune response, JAK-STAT, and NF-κB signatures. Mutational analysis revealed frequent somatic gene mutations in SOCS1, IL4R, ITPKB, and STAT6, as well as CD83 and BIRC3, with the latter genes significantly more frequently affected than in GCB DLBCL or bf-PMBL. Our data establish nm-PMBLsig+ lymphomas as a group within DLBCL with distinct phenotypic and genetic features. These findings may have implications for gene expression- and mutation-based subtyping of aggressive B-cell lymphomas and related targeted therapies.

Optical coherence tomography, intravascular ultrasound or angiography guidance for distal left main coronary stenting. The ROCK cohort II study.

OBJECTIVES: to test the safety and efficacy of intravascular imaging and specifically optical coherence tomography (OCT) as a diagnostic tool for left main angioplasty and analyze the mid-term outcome accordingly. BACKGROUND: Clinical data and international guidelines recommend the use of intravascular imaging ultrasound (IVUS) to guide left main (LM) angioplasty. Despite early experience using OCT in this setting is encouraging, the evidence supporting its use is still limited. METHODS: ROCK II is a multicenter, investigator-driven, retrospective European study to compare the performance of IVUS and OCT versus angiography in patients undergoing distal-LM stenting. The primary study endpoint was target-lesion failure (TLF) including cardiac death, target-vessel myocardial infarction and target-lesion revascularization. We designed this study hypothesizing the superiority of intravascular imaging over angiographic guidance alone, and the non-inferiority of OCT versus IVUS. RESULTS: A total of 730 patients, 377 with intravascular-imaging guidance (162 OCT, 215 IVUS) and 353 with angiographic guidance, were analyzed. The one-year rate of TLF was 21.2% with angiography and 12.7% with intravascular-imaging (p = 0.039), with no difference between OCT and IVUS (p = 0.26). Intravascular-imaging was predictor of freedom from TLF (HR 0.46; 95% CI 0.23-0.93: p = 0.03). Propensity-score matching identified three groups of 100 patients each with no significant differences in baseline characteristics. The one-year rate of TLF was 16% in the angiographic, 7% in the OCT and 6% in the IVUS group, respectively (p = 0.03 for IVUS or OCT vs. angiography). No between-group significant differences in the rate of individual components of TLF were found. CONCLUSIONS: Intravascular imaging was superior to angiography for distal LM stenting, with no difference between OCT and IVUS.

Integrative genomic analysis identifies key pathogenic mechanisms in primary mediastinal large B-cell lymphoma.

Primary mediastinal large B-cell lymphoma (PMBL) represents a clinically and pathologically distinct subtype of large B-cell lymphomas. Furthermore, molecular studies, including global gene expression profiling, have provided evidence that PMBL is more closely related to classical Hodgkin lymphoma (cHL). Although targeted sequencing studies have revealed a number of mutations involved in PMBL pathogenesis, a comprehensive description of disease-associated genetic alterations and perturbed pathways is still lacking. Here, we performed whole-exome sequencing of 95 PMBL tumors to inform on oncogenic driver genes and recurrent copy number alterations. The integration of somatic gene mutations with gene expression signatures provides further insights into genotype-phenotype interrelation in PMBL. We identified highly recurrent oncogenic mutations in the Janus kinase-signal transducer and activator of transcription and nuclear factor κB pathways, and provide additional evidence of the importance of immune evasion in PMBL (CIITA, CD58, B2M, CD274, and PDCD1LG2). Our analyses highlight the interferon response factor (IRF) pathway as a putative novel hallmark with frequent alterations in multiple pathway members (IRF2BP2, IRF4, and IRF8). In addition, our integrative analysis illustrates the importance of JAK1, RELB, and EP300 mutations driving oncogenic signaling. The identified driver genes were significantly more frequently mutated in PMBL compared with diffuse large B-cell lymphoma, whereas only a limited number of genes were significantly different between PMBL and cHL, emphasizing the close relation between these entities. Our study, performed on a large cohort of PMBL, highlights the importance of distinctive genetic alterations for disease taxonomy with relevance for diagnostic evaluation and therapeutic decision-making.

Somatic IL4R mutations in primary mediastinal large B-cell lymphoma lead to constitutive JAK-STAT signaling activation.

Primary mediastinal large B-cell lymphoma (PMBCL) is a distinct subtype of diffuse large B-cell lymphoma thought to arise from thymic medullary B cells. Gene mutations underlying the molecular pathogenesis of the disease are incompletely characterized. Here, we describe novel somatic IL4R mutations in 15 of 62 primary cases of PMBCL (24.2%) and in all PMBCL-derived cell lines tested. The majority of mutations (11/21; 52%) were hotspot single nucleotide variants in exon 8, leading to an I242N amino acid change in the transmembrane domain. Functional analyses establish this mutation as gain of function leading to constitutive activation of the JAK-STAT pathway and upregulation of downstream cytokine expression profiles and B cell-specific antigens. Moreover, expression of I242N mutant IL4R in a mouse xenotransplantation model conferred growth advantage in vivo. The pattern of concurrent mutations within the JAK-STAT signaling pathway suggests additive/synergistic effects of these gene mutations contributing to lymphomagenesis. Our data establish IL4R mutations as novel driver alterations and provide a strong preclinical rationale for therapeutic targeting of JAK-STAT signaling in PMBCL.

Calcium and calcineurin-NFAT signaling regulate granulocyte-monocyte progenitor cell cycle via Flt3-L.

Maintenance of myeloid progenitor cells is controlled by complex regulatory mechanisms and is orchestrated by multiple different transcription factors. Here, we report that the activation of the transcription factor nuclear factor of activated T cells (NFAT) by calcium-sensing protein calcineurin inhibits the proliferation of myeloid granulocyte-monocyte progenitors (GMPs). Myeloid progenitor subtypes exhibit variable sensitivity to induced Ca(2+) entry and consequently display differential engagement of the calcineurin-NFAT pathway. This study shows that inhibition of the calcineurin-NFAT pathway enhances the proliferation of GMPs both in vitro and in vivo and demonstrates that calcineurin-NFAT signaling in GMPs is initiated by Flt3-L. Inhibition of the calcineurin-NFAT pathway modified expression of the cell cycle regulation genes Cdk4, Cdk6, and Cdkn1a (p21), thus enabling rapid cell cycle progression specifically in GMPs. NFAT inhibitor drugs are extensively used in the clinic to restrict the pathological activation of lymphoid cells, and our data reveal for the first time that these therapies also exert potent effects on maintenance of the myeloid cell compartment through specific regulation of GMP proliferation.

Caspase-11: the driving factor for noncanonical inflammasomes.

Inflammasomes are large multiprotein platforms that mediate the processing of caspase-1, which in turn promotes the maturation and release of IL-1ß and IL-18 in response to microbial and danger signals. While the canonical pathway of inflammasome activation has been known for some time, a novel mechanism of noncanonical inflammasome activation mediated by caspase-11 was more recently identified. This pathway engages caspase-11 to trigger both caspase-1-dependent and -independent production of the inflammatory cytokines IL-1ß, IL-18, and IL-1α, as well as to promote pyroptosis, a form of genetically programmed cell death that is associated with the release of such cytokines. In this review, we gather together studies on both the mechanisms and implications of caspase-11-mediated noncanonical inflammasome activation, and discuss the emerging importance of this pathway in regulating host defense against intracellular bacterial pathogens.

Added value of real time three-dimensional echocardiography in the diagnosis of an apical right ventricular metastasis from malignant melanoma.

In a man presenting to the emergency room with dyspnea and atypical chest pain irradiated among the scapulae, with new-onset diffuse negative T-waves on the ECG, the first clinical and diagnostic hypothesis was pulmonary embolism (PE). However, computed tomography (CT) performed in emergency was negative for PE, showing instead a marked defect in right ventricle (RV) filling. For this reason, echocardiography was performed to better investigate the nature of the space-occupying lesion, and several echocardiographic modalities were used (two-dimensional transthoracic and transesophageal echocardiography and three-dimensional [3D] transthoracic echocardiography). They revealed the presence of a mass attached to the apex of the RV, partially obstructing the inflow and outflow tracts. Cardiac magnetic resonance imaging was also performed, confirming the findings of 3D echocardiography. After that, several other diagnostic imaging techniques were used for disease staging, since the patient had a history of surgical excision of a malignant melanoma of the skin several years before. Whole-body CT, soft tissue echography and positron emission tomography revealed the widespread diffusion of the primary tumor to distant organs. For this reason, we suspected that the RV mass could also be an intracardiac metastasis from malignant melanoma, and did not perform biopsy given the bad clinical conditions and the worse prognosis of the patient. However, he was entered in an experimental therapeutic protocol with Vemurafenib because he showed B-RAF gene mutation at molecular gene analysis.

Mature and Older Adults' Perception of Active Ageing and the Need for Supporting Services: Insights from a Qualitative Study.

The improvement in life expectancy, economic conditions, and technological and medical progress have radically changed the demographic structure of many societies. Since many countries now have an ageing population, by adopting a life-course study perspective, this paper aims to explore the needs of older adults (over 60), and the currently adult population which will become older in the coming decades (50-60 years). In detail, the study investigates the lifestyles of the target populations by focusing on two main areas concerning health (healthy diet; attitudes towards physical activity) and socio-relational-housing and living conditions (social housing, senior co-housing in rural environments, etc.). A qualitative study was carried out based on 16 in-depth interviews developed over one month (February 2022). The conduct of the interviews was supported by the Italian Center for Sensory Analysis (CIAS). Emerging from the results, the concept of active ageing is perceived by mature and older adults in a positive and optimistic way. The sample considered want to re-engage in life, continuing to be active, useful, and maintaining their self-esteem, social life and independence. However, despite older people's major concerns being preserve their physical abilities and social integration, this target group adopts behaviours focused more on current well-being rather than worrying too much about how this well-being will change as they age.

Tumor-associated antigen PRAME exhibits dualistic functions that are targetable in diffuse large B cell lymphoma.

PRAME is a prominent member of the cancer testis antigen family of proteins, which triggers autologous T cell-mediated immune responses. Integrative genomic analysis in diffuse large B cell lymphoma (DLBCL) uncovered recurrent and highly focal deletions of 22q11.22, including the PRAME gene, which were associated with poor outcome. PRAME-deleted tumors showed cytotoxic T cell immune escape and were associated with cold tumor microenvironments. In addition, PRAME downmodulation was strongly associated with somatic EZH2 Y641 mutations in DLBCL. In turn, PRC2-regulated genes were repressed in isogenic PRAME-KO lymphoma cell lines, and PRAME was found to directly interact with EZH2 as a negative regulator. EZH2 inhibition with EPZ-6438 abrogated these extrinsic and intrinsic effects, leading to PRAME expression and microenvironment restoration in vivo. Our data highlight multiple functions of PRAME during lymphomagenesis and provide a preclinical rationale for synergistic therapies combining epigenetic reprogramming with PRAME-targeted therapies.

IntravaScular Lithotripsy for the Management of UndILatable Coronary StEnt: The SMILE Registry.

BACKGROUND: Intravascular lithotripsy (IVL) showed to be effective in dilating heavily calcified de novo coronary lesions but little is known about its performance in under-expanded stents management. Aim of this study was to assess the feasibility, effectiveness and safety of IVL for the treatment of stent underexpansion refractory to balloon dilatation. METHODS: A multicentre, retrospective cohort analysis was performed in patients undergoing IVL to treat under-expanded stents following non-compliant balloon expansion failure. Primary endpoint was successful IVL dilatation defined as IVL balloon delivery and application at the target site followed by an increase of at least 1 mm2 in minimal stent cross-sectional area (MSA) on intracoronary imaging or an increase of at least 20% in minimal stent diameter (MSD) by quantitative coronary analysis (QCA). RESULTS: Thirty-nine under-expanded stents (34 patients) were included. Two cases (5.1%) of multiple stent layers and one (2.5%) acutely under-expanded stent were treated. The median IVL balloon diameter was 3.1 mm (IQR: 2.5-3.5 mm) while the number of pulses emitted was 56.7 (IQR: 30-80). IVL was successful in 34 cases (87.1%), with significant improvement in MSD (post: 3.23 mm [IQR: 3-3.5 mm] vs. pre: 0.81 mm [IQR: 0.35-1.2], p < 0.00001) and MSA (post: 7.61mm2 [IQR: 6.43-7.79mm2] vs. pre: 3.35 [IQR: 2.8-4 mm2], p < 0.00001). Non-fatal peri-procedural ST-elevation myocardial infarction occurred in one case (2.5%) due to IVL balloon rupture. No cardiac death, target lesion revascularization and stent thrombosis occurred in-hospital and at 30-day follow-up. CONCLUSIONS: Bailout IVL was feasible, efficacious and safe to improve refractory stent under-expansion.

Single-Cell Transcriptome Analysis Reveals Disease-Defining T-cell Subsets in the Tumor Microenvironment of Classic Hodgkin Lymphoma.

Hodgkin lymphoma is characterized by an extensively dominant tumor microenvironment (TME) composed of different types of noncancerous immune cells with rare malignant cells. Characterization of the cellular components and their spatial relationship is crucial to understanding cross-talk and therapeutic targeting in the TME. We performed single-cell RNA sequencing of more than 127,000 cells from 22 Hodgkin lymphoma tissue specimens and 5 reactive lymph nodes, profiling for the first time the phenotype of the Hodgkin lymphoma-specific immune microenvironment at single-cell resolution. Single-cell expression profiling identified a novel Hodgkin lymphoma-associated subset of T cells with prominent expression of the inhibitory receptor LAG3, and functional analyses established this LAG3+ T-cell population as a mediator of immunosuppression. Multiplexed spatial assessment of immune cells in the microenvironment also revealed increased LAG3+ T cells in the direct vicinity of MHC class II-deficient tumor cells. Our findings provide novel insights into TME biology and suggest new approaches to immune-checkpoint targeting in Hodgkin lymphoma. SIGNIFICANCE: We provide detailed functional and spatial characteristics of immune cells in classic Hodgkin lymphoma at single-cell resolution. Specifically, we identified a regulatory T-cell-like immunosuppressive subset of LAG3+ T cells contributing to the immune-escape phenotype. Our insights aid in the development of novel biomarkers and combination treatment strategies targeting immune checkpoints.See related commentary by Fisher and Oh, p. 342.This article is highlighted in the In This Issue feature, p. 327.

TMEM30A loss-of-function mutations drive lymphomagenesis and confer therapeutically exploitable vulnerability in B-cell lymphoma.

Transmembrane protein 30A (TMEM30A) maintains the asymmetric distribution of phosphatidylserine, an integral component of the cell membrane and 'eat-me' signal recognized by macrophages. Integrative genomic and transcriptomic analysis of diffuse large B-cell lymphoma (DLBCL) from the British Columbia population-based registry uncovered recurrent biallelic TMEM30A loss-of-function mutations, which were associated with a favorable outcome and uniquely observed in DLBCL. Using TMEM30A-knockout systems, increased accumulation of chemotherapy drugs was observed in TMEM30A-knockout cell lines and TMEM30A-mutated primary cells, explaining the improved treatment outcome. Furthermore, we found increased tumor-associated macrophages and an enhanced effect of anti-CD47 blockade limiting tumor growth in TMEM30A-knockout models. By contrast, we show that TMEM30A loss-of-function increases B-cell signaling following antigen stimulation-a mechanism conferring selective advantage during B-cell lymphoma development. Our data highlight a multifaceted role for TMEM30A in B-cell lymphomagenesis, and characterize intrinsic and extrinsic vulnerabilities of cancer cells that can be therapeutically exploited.

Continuous time Bayesian networks identify Prdm1 as a negative regulator of TH17 cell differentiation in humans.

T helper 17 (TH17) cells represent a pivotal adaptive cell subset involved in multiple immune disorders in mammalian species. Deciphering the molecular interactions regulating TH17 cell differentiation is particularly critical for novel drug target discovery designed to control maladaptive inflammatory conditions. Using continuous time Bayesian networks over a time-course gene expression dataset, we inferred the global regulatory network controlling TH17 differentiation. From the network, we identified the Prdm1 gene encoding the B lymphocyte-induced maturation protein 1 as a crucial negative regulator of human TH17 cell differentiation. The results have been validated by perturbing Prdm1 expression on freshly isolated CD4(+) naïve T cells: reduction of Prdm1 expression leads to augmentation of IL-17 release. These data unravel a possible novel target to control TH17 polarization in inflammatory disorders. Furthermore, this study represents the first in vitro validation of continuous time Bayesian networks as gene network reconstruction method and as hypothesis generation tool for wet-lab biological experiments.

Human caspase-4 and caspase-5 regulate the one-step non-canonical inflammasome activation in monocytes.

Monocytes promote the early host response to infection releasing key pro-inflammatory cytokines, such as IL-1ß. The biologically inactive IL-1ß precursor is processed to active form by inflammasomes, multi-protein complexes activating caspase-1. Human monocytes exhibit an unconventional one-step pathway of inflammasome activation in response to lipopolysaccharide (LPS) alone. Although this lineage-restricted mechanism is likely to contribute to the pathology of endotoxin shock, signalling pathways regulating this mechanism are currently unknown. Here we report that caspase-4 and caspase-5 mediate IL-1α and IL-1ß release from human monocytes after LPS stimulation. Although caspase-4 remains uncleaved, caspase-5 undergoes rapid processing upon LPS treatment. We also identify an additional caspase-5 cleavage product in LPS-stimulated monocytes, which correlates with IL-1 secretion. This one-step pathway requires Syk activity and Ca(2+) flux instigated by CD14/TLR4-mediated LPS internalization. Identification of caspase-4/5 as the key determinants of one-step inflammasome activation in human monocytes provides potential targets for therapeutic intervention in endotoxin shock.

CD103(+) Dendritic Cells Control Th17 Cell Function in the Lung.

Th17 cells express diverse functional programs while retaining their Th17 identity, in some cases exhibiting a stem-cell-like phenotype. Whereas the importance of Th17 cell regulation in autoimmune and infectious diseases is firmly established, the signaling pathways controlling their plasticity are undefined. Using a mouse model of invasive pulmonary aspergillosis, we found that lung CD103(+) dendritic cells (DCs) would produce IL-2, dependent on NFAT signaling, leading to an optimally protective Th17 response. The absence of IL-2 in DCs caused unrestrained production of IL-23 and fatal hyperinflammation, which was characterized by strong Th17 polarization and the emergence of a Th17 stem-cell-like population. Although several cell types may be affected by deficient IL-2 production in DCs, our findings identify the balance between IL-2 and IL-23 productions by lung DCs as an important regulator of the local inflammatory response to infection.

Genome-wide analysis of the genetic regulation of gene expression in human neutrophils.

Neutrophils are an abundant immune cell type involved in both antimicrobial defence and autoimmunity. The regulation of their gene expression, however, is still largely unknown. Here we report an eQTL study on isolated neutrophils from 114 healthy individuals of Chinese ethnicity, identifying 21,210 eQTLs on 832 unique genes. Unsupervised clustering analysis of these eQTLs confirms their role in inflammatory responses and immunological diseases but also indicates strong involvement in dermatological pathologies. One of the strongest eQTL identified (rs2058660) is also the tagSNP of a linkage block reported to affect leprosy and Crohn's disease in opposite directions. In a functional study, we can link the C allele with low expression of the ß-chain of IL18-receptor (IL18RAP). In neutrophils, this results in a reduced responsiveness to IL-18, detected both on the RNA and protein level. Thus, the polymorphic regulation of human neutrophils can impact beneficial as well as pathological inflammatory responses.