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1.
Cytotherapy ; 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38775775

RESUMO

BACKGROUND AIMS: Vγ9Vδ2 T cells are under investigation as alternative effector cells for adoptive cell therapy (ACT) in cancer. Despite promising in vitro results, anti-tumor efficacies in early clinical studies have been lower than expected, which could be ascribed to the complex interplay of tumor and immune cell metabolism competing for the same nutrients in the tumor microenvironment. METHODS: To contribute to the scarce knowledge regarding gamma delta T-cell metabolism, we investigated the metabolic phenotype of 25-day-expanded Vγ9Vδ2 T cells and how it is intertwined with functionality. RESULTS: We found that Vγ9Vδ2 T cells displayed a quiescent metabolism, utilizing both glycolysis and oxidative phosphorylation (OXPHOS) for energy production, as measured in Seahorse assays. Upon T-cell receptor activation, both pathways were upregulated, and inhibition with metabolic inhibitors showed that Vγ9Vδ2 T cells were dependent on glycolysis and the pentose phosphate pathway for proliferation. The dependency on glucose for proliferation was confirmed in glucose-free conditions. Cytotoxicity against malignant melanoma was reduced by glycolysis inhibition but not OXPHOS inhibition. CONCLUSIONS: These findings lay the groundwork for further studies on manipulation of Vγ9Vδ2 T-cell metabolism for improved ACT outcome.

2.
Nat Commun ; 15(1): 3173, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609390

RESUMO

Semaphorin-3A (SEMA3A) functions as a chemorepulsive signal during development and can affect T cells by altering their filamentous actin (F-actin) cytoskeleton. The exact extent of these effects on tumour-specific T cells are not completely understood. Here we demonstrate that Neuropilin-1 (NRP1) and Plexin-A1 and Plexin-A4 are upregulated on stimulated CD8+ T cells, allowing tumour-derived SEMA3A to inhibit T cell migration and assembly of the immunological synapse. Deletion of NRP1 in both CD4+ and CD8+ T cells enhance CD8+ T-cell infiltration into tumours and restricted tumour growth in animal models. Conversely, over-expression of SEMA3A inhibit CD8+ T-cell infiltration. We further show that SEMA3A affects CD8+ T cell F-actin, leading to inhibition of immune synapse formation and motility. Examining a clear cell renal cell carcinoma patient cohort, we find that SEMA3A expression is associated with reduced survival, and that T-cells appear trapped in SEMA3A rich regions. Our study establishes SEMA3A as an inhibitor of effector CD8+ T cell tumour infiltration, suggesting that blocking NRP1 could improve T cell function in tumours.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Animais , Humanos , Actinas , Linfócitos T CD8-Positivos , Citoesqueleto , Semaforina-3A/genética
4.
Cell Rep Methods ; 4(3): 100731, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38490204

RESUMO

Systems vaccinology studies have identified factors affecting individual vaccine responses, but comparing these findings is challenging due to varying study designs. To address this lack of reproducibility, we established a community resource for comparing Bordetella pertussis booster responses and to host annual contests for predicting patients' vaccination outcomes. We report here on our experiences with the "dry-run" prediction contest. We found that, among 20+ models adopted from the literature, the most successful model predicting vaccination outcome was based on age alone. This confirms our concerns about the reproducibility of conclusions between different vaccinology studies. Further, we found that, for newly trained models, handling of baseline information on the target variables was crucial. Overall, multiple co-inertia analysis gave the best results of the tested modeling approaches. Our goal is to engage community in these prediction challenges by making data and models available and opening a public contest in August 2024.


Assuntos
Multiômica , Vacinas , Humanos , Vacinologia/métodos , Reprodutibilidade dos Testes , Simulação por Computador
5.
bioRxiv ; 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38405900

RESUMO

Understanding how intra-tumoral immune populations coordinate to generate anti-tumor responses following therapy can guide precise treatment prioritization. We performed systematic dissection of an established adoptive cellular therapy, donor lymphocyte infusion (DLI), by analyzing 348,905 single-cell transcriptomes from 74 longitudinal bone-marrow samples of 25 patients with relapsed myeloid leukemia; a subset was evaluated by protein-based spatial analysis. In acute myelogenous leukemia (AML) responders, diverse immune cell types within the bone-marrow microenvironment (BME) were predicted to interact with a clonally expanded population of ZNF683 + GZMB + CD8+ cytotoxic T lymphocytes (CTLs) which demonstrated in vitro specificity for autologous leukemia. This population, originating predominantly from the DLI product, expanded concurrently with NK and B cells. AML nonresponder BME revealed a paucity of crosstalk and elevated TIGIT expression in CD8+ CTLs. Our study highlights recipient BME differences as a key determinant of effective anti-leukemia response and opens new opportunities to modulate cell-based leukemia-directed therapy.

6.
Eur J Haematol ; 112(5): 776-787, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38226781

RESUMO

BACKGROUND: Essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (MF) are myeloproliferative neoplasms (MPN). Inflammation is involved in the initiation, progression, and symptomology of the diseases. The gut microbiota impacts the immune system, infection control, and steady-state hematopoiesis. METHODS: We analyzed the gut microbiota of 227 MPN patients and healthy controls (HCs) using next-generation sequencing. We expanded our previous results in PV and ET patients with additional PV, pre-MF, and MF patients which allowed us to compare MPN patients collectively, MPN sub-diagnoses, and MPN mutations (separately and combined) vs. HCs (N = 42) and compare within MPN sub-diagnoses and MPN mutation. RESULTS: MPN patients had a higher observed richness (median, 245 [range, 49-659]) compared with HCs (191.5 [range, 111-300; p = .003]) and a lower relative abundance of taxa within the Firmicutes phylum; for example, Faecalibacterium (6% vs. 14%, p < .001). The microbiota of CALR-positive patients (N = 30) resembled that of HCs more than that of patients with JAK2V617F (N = 177). In JAK2V617F-positive patients, only minor differences in the gut microbiota were observed between MPN sub-diagnoses, illustrating the importance of this mutation. CONCLUSION: The gut microbiota in MPN patients differs from HCs and is driven by JAK2V617F, whereas the gut microbiota in CALR patients resembles HCs more.


Assuntos
Microbioma Gastrointestinal , Transtornos Mieloproliferativos , Policitemia Vera , Trombocitemia Essencial , Humanos , Calreticulina/genética , Janus Quinase 2/genética , Transtornos Mieloproliferativos/etiologia , Transtornos Mieloproliferativos/genética , Policitemia Vera/genética , Mutação , Trombocitemia Essencial/genética
7.
Mol Oncol ; 18(3): 606-619, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38158740

RESUMO

Molecular subtyping is essential to infer tumor aggressiveness and predict prognosis. In practice, tumor profiling requires in-depth knowledge of bioinformatics tools involved in the processing and analysis of the generated data. Additionally, data incompatibility (e.g., microarray versus RNA sequencing data) and technical and uncharacterized biological variance between training and test data can pose challenges in classifying individual samples. In this article, we provide a roadmap for implementing bioinformatics frameworks for molecular profiling of human cancers in a clinical diagnostic setting. We describe a framework for integrating several methods for quality control, normalization, batch correction, classification and reporting, and develop a use case of the framework in breast cancer.


Assuntos
Neoplasias da Mama , Perfilação da Expressão Gênica , Humanos , Feminino , Perfilação da Expressão Gênica/métodos , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , RNA , Biologia Computacional/métodos , Regulação Neoplásica da Expressão Gênica
8.
BMC Biol ; 21(1): 220, 2023 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-37858135

RESUMO

BACKGROUND: Through alternative splicing, most human genes produce multiple isoforms in a cell-, tissue-, and disease-specific manner. Numerous studies show that alternative splicing is essential for development, diseases, and their treatments. Despite these important examples, the extent and biological relevance of splicing are currently unknown. RESULTS: To solve this problem, we developed pairedGSEA and used it to profile transcriptional changes in 100 representative RNA-seq datasets. Our systematic analysis demonstrates that changes in splicing, on average, contribute to 48.1% of the biological signal in expression analyses. Gene-set enrichment analysis furthermore indicates that expression and splicing both convey shared and distinct biological signals. CONCLUSIONS: These findings establish alternative splicing as a major regulator of the human condition and suggest that most contemporary RNA-seq studies likely miss out on critical biological insights. We anticipate our results will contribute to the transition from a gene-centric to an isoform-centric research paradigm.


Assuntos
Perfilação da Expressão Gênica , Splicing de RNA , Humanos , Perfilação da Expressão Gênica/métodos , Processamento Alternativo , RNA-Seq , Análise de Sequência de RNA/métodos , Isoformas de Proteínas/genética
9.
bioRxiv ; 2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37693565

RESUMO

Computational models that predict an individual's response to a vaccine offer the potential for mechanistic insights and personalized vaccination strategies. These models are increasingly derived from systems vaccinology studies that generate immune profiles from human cohorts pre- and post-vaccination. Most of these studies involve relatively small cohorts and profile the response to a single vaccine. The ability to assess the performance of the resulting models would be improved by comparing their performance on independent datasets, as has been done with great success in other areas of biology such as protein structure predictions. To transfer this approach to system vaccinology studies, we established a prototype platform that focuses on the evaluation of Computational Models of Immunity to Pertussis Booster vaccinations (CMI-PB). A community resource, CMI-PB generates experimental data for the explicit purpose of model evaluation, which is performed through a series of annual data releases and associated contests. We here report on our experience with the first such 'dry run' for a contest where the goal was to predict individual immune responses based on pre-vaccination multi-omic profiles. Over 30 models adopted from the literature were tested, but only one was predictive, and was based on age alone. The performance of new models built using CMI-PB training data was much better, but varied significantly based on the choice of pre-vaccination features used and the model building strategy. This suggests that previously published models developed for other vaccines do not generalize well to Pertussis Booster vaccination. Overall, these results reinforced the need for comparative analysis across models and datasets that CMI-PB aims to achieve. We are seeking wider community engagement for our first public prediction contest, which will open in early 2024.

10.
Microbiol Spectr ; : e0066223, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37695126

RESUMO

Essential thrombocythemia (ET) is part of the Philadelphia chromosome-negative myeloproliferative neoplasms. It is characterized by an increased risk of thromboembolic events and also to a certain degree hypermetabolic symptoms. The gut microbiota is an important initiator of hematopoiesis and regulation of the immune system, but in patients with ET, where inflammation is a hallmark of the disease, it is vastly unexplored. In this study, we compared the gut microbiota via amplicon-based 16S rRNA gene sequencing of the V3-V4 region in 54 patients with ET according to mutation status Janus-kinase 2 (JAK2V617F)-positive vs JAK2V617F-negative patients with ET, and in 42 healthy controls (HCs). Gut microbiota richness was higher in patients with ET (median-observed richness, 283.5; range, 75-535) compared with HCs (median-observed richness, 191.5; range, 111-300; P < 0.001). Patients with ET had a different overall bacterial composition (beta diversity) than HCs (analysis of similarities [ANOSIM]; R = 0.063, P = 0.004). Patients with ET had a significantly lower relative abundance of taxa within the Firmicutes phylum compared with HCs (51% vs 59%, P = 0.03), and within that phylum, patients with ET also had a lower relative abundance of the genus Faecalibacterium (8% vs 15%, P < 0.001), an important immunoregulative bacterium. The microbiota signatures were more pronounced in patients harboring the JAK2V617F mutation, and highly similar to patients with polycythemia vera as previously described. These findings suggest that patients with ET may have an altered immune regulation; however, whether this dysregulation is induced in part by, or is itself inducing, an altered gut microbiota remains to be investigated. IMPORTANCE Essential thrombocythemia (ET) is a cancer characterized by thrombocyte overproduction. Inflammation has been shown to be vital in both the initiation and progression of other myeloproliferative neoplasms, and it is well known that the gut microbiota is important in the regulation of our immune system. However, the gut microbiota of patients with ET remains uninvestigated. In this study, we characterized the gut microbiota of patients with ET compared with healthy controls and thereby provide new insights into the field. We show that the gut microbiota of patients with ET differs significantly from that of healthy controls and the patients with ET have a lower relative abundance of important immunoregulative bacteria. Furthermore, we demonstrate that patients with JAK2V617F-positive ET have pronounced gut microbiota signatures compared with JAK2V617F-negative patients. Thereby confirming the importance of the underlying mutation, the immune response as well as the composition of the microbiota.

11.
Cancer Cell ; 41(10): 1803-1816.e8, 2023 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-37738974

RESUMO

Unlike many other hematologic malignancies, Richter syndrome (RS), an aggressive B cell lymphoma originating from indolent chronic lymphocytic leukemia, is responsive to PD-1 blockade. To discover the determinants of response, we analyze single-cell transcriptome data generated from 17 bone marrow samples longitudinally collected from 6 patients with RS. Response is associated with intermediate exhausted CD8 effector/effector memory T cells marked by high expression of the transcription factor ZNF683, determined to be evolving from stem-like memory cells and divergent from terminally exhausted cells. This signature overlaps with that of tumor-infiltrating populations from anti-PD-1 responsive solid tumors. ZNF683 is found to directly target key T cell genes (TCF7, LMO2, CD69) and impact pathways of T cell cytotoxicity and activation. Analysis of pre-treatment peripheral blood from 10 independent patients with RS treated with anti-PD-1, as well as patients with solid tumors treated with anti-PD-1, supports an association of ZNF683high T cells with response.


Assuntos
Leucemia Linfocítica Crônica de Células B , Linfoma Difuso de Grandes Células B , Humanos , Leucemia Linfocítica Crônica de Células B/patologia , Linfócitos T CD8-Positivos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Regulação da Expressão Gênica , Imunoterapia
12.
Chaos ; 33(2): 023102, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36859227

RESUMO

A previously overlooked version of the so-called Olsen model of the peroxidase-oxidase reaction has been studied numerically using 2D isospike stability and maximum Lyapunov exponent diagrams and reveals a rich variety of dynamic behaviors not observed before. The model has a complex bifurcation structure involving mixed-mode and bursting oscillations as well as quasiperiodic and chaotic dynamics. In addition, multiple periodic and non-periodic attractors coexist for the same parameters. For some parameter values, the model also reveals formation of mosaic patterns of complex dynamic states. The complex dynamic behaviors exhibited by this model are compared to those of another version of the same model, which has been studied in more detail. The two models show similarities, but also notable differences between them, e.g., the organization of mixed-mode oscillations in parameter space and the relative abundance of quasiperiodic and chaotic oscillations. In both models, domains with chaotic dynamics contain apparently disorganized subdomains of periodic attractors with dinoflagellate-like structures, while the domains with mainly quasiperiodic behavior contain subdomains with periodic attractors organized as regular filamentous structures. These periodic attractors seem to be organized according to Stern-Brocot arithmetics. Finally, it appears that toroidal (quasiperiodic) attractors develop into first wrinkled and then fractal tori before they break down to chaotic attractors.

13.
Cell Stem Cell ; 30(1): 38-51.e8, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36563694

RESUMO

MODY3 is a monogenic hereditary form of diabetes caused by mutations in the transcription factor HNF1A. The patients progressively develop hyperglycemia due to perturbed insulin secretion, but the pathogenesis is unknown. Using patient-specific hiPSCs, we recapitulate the insulin secretion sensitivity to the membrane depolarizing agent sulfonylurea commonly observed in MODY3 patients. Unexpectedly, MODY3 patient-specific HNF1A+/R272C ß cells hypersecrete insulin both in vitro and in vivo after transplantation into mice. Consistently, we identified a trend of increased birth weight in human HNF1A mutation carriers compared with healthy siblings. Reduced expression of potassium channels, specifically the KATP channel, in MODY3 ß cells, increased calcium signaling, and rescue of the insulin hypersecretion phenotype by pharmacological targeting ATP-sensitive potassium channels or low-voltage-activated calcium channels suggest that more efficient membrane depolarization underlies the hypersecretion of insulin in MODY3 ß cells. Our findings identify a pathogenic mechanism leading to ß cell failure in MODY3.


Assuntos
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Humanos , Camundongos , Animais , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Diabetes Mellitus Tipo 2/genética , Fenótipo
14.
Blood Adv ; 7(13): 3326-3337, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-36260736

RESUMO

Chronic inflammation is believed to play an important role in the development and disease progression of polycythemia vera (PV). Because an association between gut microbiota, hematopoiesis, and inflammation is well established, we hypothesized that patients with PV have a gut microbiota distinct from healthy control participants (HCs). Recombinant interferon alfa 2 (IFN-α2)-treatment of patients with PV is reportedly disease modifying in terms of normalization of elevated blood cell counts in concert with a reduction in the JAK2V617F allelic burden. Therefore, we hypothesized that patients treated with IFN-α2 might have a composition of the gut microbiota toward normalization. Herein, via amplicon-based next-generation sequencing of the V3 to V4 regions of the 16S ribosomal RNA gene, we report on an abnormal gut microbiota in 102 patients with PV compared with 42 HCs. Patients with PV had a lower alpha diversity and a lower relative abundance of several taxa belonging to Firmicutes (45%) compared with HCs (59%, P <.001). Furthermore, we report the composition of the gut microbiota to differ between the treatment groups (IFN-α2, hydroxyurea, no treatment, and combination therapy with IFN-α2 and ruxolitinib) and the HCs. These observations are highly interesting considering the potential pathogenetic importance of an altered gut microbiota for development of other diseases, including chronic inflammatory diseases. Our observations call for further gut microbiota studies to decipher potential causal associations between treatment and the gut microbiota in PV and related neoplasms.


Assuntos
Microbioma Gastrointestinal , Policitemia Vera , Humanos , Policitemia Vera/tratamento farmacológico , Policitemia Vera/genética , Interferon-alfa/uso terapêutico , Hidroxiureia , Inflamação
15.
BJGP Open ; 7(1)2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36564082

RESUMO

BACKGROUND: Depression is common in old age and is associated with disability, increased mortality, and impairment from physical diseases. AIM: To estimate the prevalence of depression among older patients in Norwegian general practice, to evaluate the extent they talk about it during their consultation, whether it was previously known or suspected by their GP, and how frequently patients with depression visit their GP. DESIGN & SETTING: Cross-sectional study among patients and GPs at 18 primary care clinics in the south of Norway. METHOD: Patients aged ≥65 years who visited their GP were asked to complete the Patient Health Questionnaire-9 (PHQ-9). The GPs reported what kind of issues the patient presented at the consultation, if a current depression was known, and the consultation frequency. RESULTS: Forty-four (11.4%) of 383 patients reported moderate or severe depressive symptoms (PHQ-9 ≥10). Among the cases with data from both patient and GP (n = 369), 38 patients (10.3%) reported moderately depressive symptoms. Of these, only 12 (31.6%) mentioned psychological problems to their GP during their consultation; 12 (31.6%) with previous depression were neither known to the GP nor suspected of currently having depression; and 67.6% of them visited their GP ≥5 times a year. CONCLUSION: Older patients tend to speak little of their depression to the GP. Almost one in three older patients with moderate depressive symptoms were unrecognised by their GP. Older patients who frequently visit the GP should be suspected of potentially having mental health problems.

16.
J Biol Chem ; 298(12): 102680, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36356902

RESUMO

The poisonous metalloid arsenite induces widespread misfolding and aggregation of nascent proteins in vivo, and this mode of toxic action might underlie its suspected role in the pathology of certain protein misfolding diseases. Evolutionarily conserved protein quality-control systems protect cells against arsenite-mediated proteotoxicity, and herein, we systematically assessed the contribution of the ubiquitin-proteasome system, the autophagy-vacuole pathway, and chaperone-mediated disaggregation to the clearance of arsenite-induced protein aggregates in Saccharomyces cerevisiae. We show that the ubiquitin-proteasome system is the main pathway that clears aggregates formed during arsenite stress and that cells depend on this pathway for optimal growth. The autophagy-vacuole pathway and chaperone-mediated disaggregation both contribute to clearance, but their roles appear less prominent than the ubiquitin-proteasome system. Our in vitro assays with purified components of the yeast disaggregating machinery demonstrated that chaperone binding to aggregates formed in the presence of arsenite is impaired. Hsp104 and Hsp70 chaperone activity was unaffected by arsenite, suggesting that this metalloid influences aggregate structure, making them less accessible for chaperone-mediated disaggregation. We further show that the defect in chaperone-mediated refolding of a model protein was abrogated in a cysteine-free version of the substrate, suggesting that arsenite directly modifies cysteines in non-native target proteins. In conclusion, our study sheds novel light on the differential contributions of protein quality-control systems to aggregate clearance and cell proliferation and extends our understanding of how these systems operate during arsenite stress.


Assuntos
Arsenitos , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Agregados Proteicos , Arsenitos/farmacologia , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Ubiquitina/metabolismo , Autofagia , Proteínas de Choque Térmico/metabolismo
17.
Oncoimmunology ; 11(1): 2115655, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36052217

RESUMO

CCL22 is a macrophage-derived immunosuppressive chemokine that recruits regulatory T cells through the CCL22:CCR4 axis. CCL22 was shown to play a key role in suppressing anti-cancer immune responses in different cancer types. Recently, we showed that CCL22-specific T cells generated from cancer patients could kill CCL22-expressing tumor cells and directly influence the levels of CCL22 in vitro. The present study aimed to provide a rationale for developing a CCL22-targeting immunotherapy. Vaccination with CCL22-derived peptides induced CCL22-specific T-cell responses in both BALB/c and C57BL/6 mice, assessed by interferon-γ secretion ex vivo. Anti-tumor efficacy of the peptides was evaluated in mouse models engrafted with syngeneic tumor models showing a reduced tumor growth and prolonged survival of the treated mice. Vaccination induced changes in the cellular composition of immune cells that infiltrated the tumor microenvironment assessed with multicolor flow cytometry. In particular, the infiltration of CD8+ cells and M1 macrophages increased, which increased the CD8/Treg and the M1/M2 macrophage ratio. This study provided preclinical evidence that targeting CCL22 with CCL22 peptide vaccines modulated the immune milieu in the tumor microenvironment. This modulation led to an augmentation of anti-tumor responses. This study provided a rationale for developing a novel immunotherapeutic modality in cancer.


Assuntos
Neoplasias , Microambiente Tumoral , Animais , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Neoplasias/patologia , Linfócitos T Reguladores , Vacinas de Subunidades Antigênicas
18.
Immunother Adv ; 2(1): ltac009, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35919495

RESUMO

The development of novel chimeric antigen receptor (CAR) cell therapies is rapidly growing, with 299 new agents being reported and 109 new clinical trials initiated so far this year. One critical lesson from approved CD19-specific CAR therapies is that target isoform switching has been shown to cause tumour relapse, but little is known about the isoforms of CAR targets in solid cancers. Here we assess the protein isoform landscape and identify both the challenges and opportunities protein isoform switching present as CAR therapy is applied to solid cancers.

19.
J Clin Invest ; 132(13)2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35775490

RESUMO

Cancers avoid immune surveillance through an array of mechanisms, including perturbation of HLA class I antigen presentation. Merkel cell carcinoma (MCC) is an aggressive, HLA-I-low, neuroendocrine carcinoma of the skin often caused by the Merkel cell polyomavirus (MCPyV). Through the characterization of 11 newly generated MCC patient-derived cell lines, we identified transcriptional suppression of several class I antigen presentation genes. To systematically identify regulators of HLA-I loss in MCC, we performed parallel, genome-scale, gain- and loss-of-function screens in a patient-derived MCPyV-positive cell line and identified MYCL and the non-canonical Polycomb repressive complex 1.1 (PRC1.1) as HLA-I repressors. We observed physical interaction of MYCL with the MCPyV small T viral antigen, supporting a mechanism of virally mediated HLA-I suppression. We further identify the PRC1.1 component USP7 as a pharmacologic target to restore HLA-I expression in MCC.


Assuntos
Carcinoma de Célula de Merkel , Poliomavírus das Células de Merkel , Infecções por Polyomavirus , Neoplasias Cutâneas , Antígenos Virais de Tumores/genética , Antígenos Virais de Tumores/metabolismo , Carcinoma de Célula de Merkel/genética , Carcinoma de Célula de Merkel/patologia , Epigênese Genética , Humanos , Poliomavírus das Células de Merkel/genética , Poliomavírus das Células de Merkel/metabolismo , Infecções por Polyomavirus/genética , Neoplasias Cutâneas/patologia , Peptidase 7 Específica de Ubiquitina/metabolismo
20.
Chaos ; 32(6): 063122, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35778127

RESUMO

The peroxidase-oxidase (PO) reaction is a paradigmatic (bio)chemical system well suited to study the organization and stability of self-sustained oscillatory phases typically present in nonlinear systems. The PO reaction can be simulated by the state-of-the-art Bronnikova-Fedkina-Schaffer-Olsen model involving ten coupled ordinary differential equations. The complex and dynamically rich distribution of self-sustained oscillatory stability phases of this model was recently investigated in detail. However, would it be possible to understand aspects of such a complex model using much simpler models? Here, we investigate stability phases predicted by three simple four-variable subnetworks derived from the complete model. While stability diagrams for such subnetworks are found to be distorted compared to those of the complete model, we find them to surprisingly preserve significant features of the original model as well as from the experimental system, e.g., period-doubling and period-adding scenarios. In addition, return maps obtained from the subnetworks look very similar to maps obtained in the experimental system under different conditions. Finally, two of the three subnetwork models are found to exhibit quint points, i.e., recently reported singular points where five distinct stability phases coalesce. We also provide experimental evidence that such quint points are present in the PO reaction.


Assuntos
Oxirredutases , Peroxidases
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