RESUMEN
The T cells of the immune system can target tumors and clear solid cancers following tumor-infiltrating lymphocyte (TIL) therapy. We used combinatorial peptide libraries and a proteomic database to reveal the antigen specificities of persistent cancer-specific T cell receptors (TCRs) following successful TIL therapy for stage IV malignant melanoma. Remarkably, individual TCRs could target multiple different tumor types via the HLA A∗02:01-restricted epitopes EAAGIGILTV, LLLGIGILVL, and NLSALGIFST from Melan A, BST2, and IMP2, respectively. Atomic structures of a TCR bound to all three antigens revealed the importance of the shared x-x-x-A/G-I/L-G-I-x-x-x recognition motif. Multi-epitope targeting allows individual T cells to attack cancer in several ways simultaneously. Such "multipronged" T cells exhibited superior recognition of cancer cells compared with conventional T cell recognition of individual epitopes, making them attractive candidates for the development of future immunotherapies.
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Antígenos de Neoplasias , Neoplasias , Proteómica , Receptores de Antígenos de Linfocitos T , Antígenos de Neoplasias/metabolismo , Epítopos , Inmunoterapia , Linfocitos Infiltrantes de Tumor , Neoplasias/inmunología , Neoplasias/terapia , Receptores de Antígenos de Linfocitos T/metabolismoRESUMEN
We studied the prevalent cytotoxic CD8 T cell response mounted against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Spike glycoprotein269-277 epitope (sequence YLQPRTFLL) via the most frequent human leukocyte antigen (HLA) class I worldwide, HLA A∗02. The Spike P272L mutation that has arisen in at least 112 different SARS-CoV-2 lineages to date, including in lineages classified as "variants of concern," was not recognized by the large CD8 T cell response seen across cohorts of HLA A∗02+ convalescent patients and individuals vaccinated against SARS-CoV-2, despite these responses comprising of over 175 different individual T cell receptors. Viral escape at prevalent T cell epitopes restricted by high frequency HLAs may be particularly problematic when vaccine immunity is focused on a single protein such as SARS-CoV-2 Spike, providing a strong argument for inclusion of multiple viral proteins in next generation vaccines and highlighting the need for monitoring T cell escape in new SARS-CoV-2 variants.
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COVID-19 , SARS-CoV-2 , Linfocitos T CD8-positivos , Epítopos de Linfocito T , Antígenos HLA-A , Antígenos de Histocompatibilidad Clase I , HumanosRESUMEN
Targeted protein degradation (TPD) refers to the use of small molecules to induce ubiquitin-dependent degradation of proteins. TPD is of interest in drug development, as it can address previously inaccessible targets. However, degrader discovery and optimization remains an inefficient process due to a lack of understanding of the relative importance of the key molecular events required to induce target degradation. Here, we use chemo-proteomics to annotate the degradable kinome. Our expansive dataset provides chemical leads for â¼200 kinases and demonstrates that the current practice of starting from the highest potency binder is an ineffective method for discovering active compounds. We develop multitargeted degraders to answer fundamental questions about the ubiquitin proteasome system, uncovering that kinase degradation is p97 dependent. This work will not only fuel kinase degrader discovery, but also provides a blueprint for evaluating targeted degradation across entire gene families to accelerate understanding of TPD beyond the kinome.
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Proteínas Quinasas/metabolismo , Proteolisis , Proteoma/metabolismo , Adulto , Línea Celular , Bases de Datos de Proteínas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteínas Quinasas/genética , Proteómica , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Adulto JovenRESUMEN
DNA methylation at the 5 position of cytosine (5-mC) is a key epigenetic mark that is critical for various biological and pathological processes. 5-mC can be converted to 5-hydroxymethylcytosine (5-hmC) by the ten-eleven translocation (TET) family of DNA hydroxylases. Here, we report that "loss of 5-hmC" is an epigenetic hallmark of melanoma, with diagnostic and prognostic implications. Genome-wide mapping of 5-hmC reveals loss of the 5-hmC landscape in the melanoma epigenome. We show that downregulation of isocitrate dehydrogenase 2 (IDH2) and TET family enzymes is likely one of the mechanisms underlying 5-hmC loss in melanoma. Rebuilding the 5-hmC landscape in melanoma cells by reintroducing active TET2 or IDH2 suppresses melanoma growth and increases tumor-free survival in animal models. Thus, our study reveals a critical function of 5-hmC in melanoma development and directly links the IDH and TET activity-dependent epigenetic pathway to 5-hmC-mediated suppression of melanoma progression, suggesting a new strategy for epigenetic cancer therapy.
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Citosina/análogos & derivados , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Melanoma/genética , Nevo/genética , 5-Metilcitosina/análogos & derivados , Citosina/metabolismo , Proteínas de Unión al ADN/genética , Dioxigenasas , Estudio de Asociación del Genoma Completo , Humanos , Isocitrato Deshidrogenasa/genética , Melanocitos/metabolismo , Melanoma/patología , Nevo/patología , Proteínas Proto-Oncogénicas/genéticaRESUMEN
METTL3 (methyltransferase-like 3) mediates the N6-methyladenosine (m6A) methylation of mRNA, which affects the stability of mRNA and its translation into protein1. METTL3 also binds chromatin2-4, but the role of METTL3 and m6A methylation in chromatin is not fully understood. Here we show that METTL3 regulates mouse embryonic stem-cell heterochromatin, the integrity of which is critical for silencing retroviral elements and for mammalian development5. METTL3 predominantly localizes to the intracisternal A particle (IAP)-type family of endogenous retroviruses. Knockout of Mettl3 impairs the deposition of multiple heterochromatin marks onto METTL3-targeted IAPs, and upregulates IAP transcription, suggesting that METTL3 is important for the integrity of IAP heterochromatin. We provide further evidence that RNA transcripts derived from METTL3-bound IAPs are associated with chromatin and are m6A-methylated. These m6A-marked transcripts are bound by the m6A reader YTHDC1, which interacts with METTL3 and in turn promotes the association of METTL3 with chromatin. METTL3 also interacts physically with the histone 3 lysine 9 (H3K9) tri-methyltransferase SETDB1 and its cofactor TRIM28, and is important for their localization to IAPs. Our findings demonstrate that METTL3-catalysed m6A modification of RNA is important for the integrity of IAP heterochromatin in mouse embryonic stem cells, revealing a mechanism of heterochromatin regulation in mammals.
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Ensamble y Desensamble de Cromatina , Heterocromatina/genética , Heterocromatina/metabolismo , Metiltransferasas/metabolismo , Células Madre Embrionarias de Ratones/metabolismo , Animales , Retrovirus Endógenos/genética , Regulación de la Expresión Génica , Genes de Partícula A Intracisternal/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Histonas/química , Histonas/metabolismo , Ratones , Proteína 28 que Contiene Motivos Tripartito/metabolismoRESUMEN
All respiratory viruses establish primary infections in the nasal epithelium, where efficient innate immune induction may prevent dissemination to the lower airway and thus minimize pathogenesis. Human coronaviruses (HCoVs) cause a range of pathologies, but the host and viral determinants of disease during common cold versus lethal HCoV infections are poorly understood. We model the initial site of infection using primary nasal epithelial cells cultured at an air-liquid interface (ALI). HCoV-229E, HCoV-NL63, and human rhinovirus-16 are common cold-associated viruses that exhibit unique features in this model: early induction of antiviral interferon (IFN) signaling, IFN-mediated viral clearance, and preferential replication at nasal airway temperature (33 °C) which confers muted host IFN responses. In contrast, lethal SARS-CoV-2 and MERS-CoV encode antagonist proteins that prevent IFN-mediated clearance in nasal cultures. Our study identifies features shared among common cold-associated viruses, highlighting nasal innate immune responses as predictive of infection outcomes and nasally directed IFNs as potential therapeutics.
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Resfriado Común , Inmunidad Innata , Interferones , Mucosa Nasal , SARS-CoV-2 , Transducción de Señal , Humanos , Mucosa Nasal/virología , Mucosa Nasal/inmunología , Mucosa Nasal/metabolismo , Interferones/metabolismo , Interferones/inmunología , Resfriado Común/inmunología , Resfriado Común/virología , Transducción de Señal/inmunología , SARS-CoV-2/inmunología , Replicación Viral , Rhinovirus/inmunología , Coronavirus Humano 229E/inmunología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Células Epiteliales/virología , Células Epiteliales/inmunología , Células Epiteliales/metabolismo , Coronavirus del Síndrome Respiratorio de Oriente Medio/inmunología , Coronavirus Humano NL63/inmunologíaRESUMEN
α-synuclein (α-syn) assembles into structurally distinct fibril polymorphs seen in different synucleinopathies, such as Parkinson's disease and multiple system atrophy. Targeting these unique fibril structures using chemical ligands holds diagnostic significance for different disease subtypes. However, the molecular mechanisms governing small molecules interacting with different fibril polymorphs remain unclear. Here, we investigated the interactions of small molecules belonging to four distinct scaffolds, with different α-syn fibril polymorphs. Using cryo-electron microscopy, we determined the structures of these molecules when bound to the fibrils formed by E46K mutant α-syn and compared them to those bound with wild-type α-syn fibrils. Notably, we observed that these ligands exhibit remarkable binding adaptability, as they engage distinct binding sites across different fibril polymorphs. While the molecular scaffold primarily steered the binding locations and geometries on specific sites, the conjugated functional groups further refined this adaptable binding by fine-tuning the geometries and binding sites. Overall, our finding elucidates the adaptability of small molecules binding to different fibril structures, which sheds light on the diagnostic tracer and drug developments tailored to specific pathological fibril polymorphs.
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Amiloide , Microscopía por Crioelectrón , alfa-Sinucleína , alfa-Sinucleína/metabolismo , alfa-Sinucleína/química , Amiloide/metabolismo , Amiloide/química , Ligandos , Humanos , Sitios de Unión , Unión Proteica , Enfermedad de Parkinson/metabolismo , MutaciónRESUMEN
Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has caused millions of deaths since its emergence in 2019. Innate immune antagonism by lethal CoVs such as SARS-CoV-2 is crucial for optimal replication and pathogenesis. The conserved nonstructural protein 15 (nsp15) endoribonuclease (EndoU) limits activation of double-stranded (ds)RNA-induced pathways, including interferon (IFN) signaling, protein kinase R (PKR), and oligoadenylate synthetase/ribonuclease L (OAS/RNase L) during diverse CoV infections including murine coronavirus and Middle East respiratory syndrome (MERS)-CoV. To determine how nsp15 functions during SARS-CoV-2 infection, we constructed a recombinant SARS-CoV-2 (nsp15mut) expressing catalytically inactivated nsp15, which we show promoted increased dsRNA accumulation. Infection with SARS-CoV-2 nsp15mut led to increased activation of the IFN signaling and PKR pathways in lung-derived epithelial cell lines and primary nasal epithelial air-liquid interface (ALI) cultures as well as significant attenuation of replication in ALI cultures compared to wild-type virus. This replication defect was rescued when IFN signaling was inhibited with the Janus activated kinase (JAK) inhibitor ruxolitinib. Finally, to assess nsp15 function in the context of minimal (MERS-CoV) or moderate (SARS-CoV-2) innate immune induction, we compared infections with SARS-CoV-2 nsp15mut and previously described MERS-CoV nsp15 mutants. Inactivation of nsp15 had a more dramatic impact on MERS-CoV replication than SARS-CoV-2 in both Calu3 cells and nasal ALI cultures suggesting that SARS-CoV-2 can better tolerate innate immune responses. Taken together, SARS-CoV-2 nsp15 is a potent inhibitor of dsRNA-induced innate immune response and its antagonism of IFN signaling is necessary for optimal viral replication in primary nasal ALI cultures.
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COVID-19 , SARS-CoV-2 , Animales , Ratones , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Endorribonucleasas/metabolismo , Transducción de Señal , AntiviralesRESUMEN
Cell death in human diseases is often a consequence of disrupted cellular homeostasis. If cell death is prevented without restoring cellular homeostasis, it may lead to a persistent dysfunctional and pathological state. Although mechanisms of cell death have been thoroughly investigated1-3, it remains unclear how homeostasis can be restored after inhibition of cell death. Here we identify TRADD4-6, an adaptor protein, as a direct regulator of both cellular homeostasis and apoptosis. TRADD modulates cellular homeostasis by inhibiting K63-linked ubiquitination of beclin 1 mediated by TRAF2, cIAP1 and cIAP2, thereby reducing autophagy. TRADD deficiency inhibits RIPK1-dependent extrinsic apoptosis and proteasomal stress-induced intrinsic apoptosis. We also show that the small molecules ICCB-19 and Apt-1 bind to a pocket on the N-terminal TRAF2-binding domain of TRADD (TRADD-N), which interacts with the C-terminal domain (TRADD-C) and TRAF2 to modulate the ubiquitination of RIPK1 and beclin 1. Inhibition of TRADD by ICCB-19 or Apt-1 blocks apoptosis and restores cellular homeostasis by activating autophagy in cells with accumulated mutant tau, α-synuclein, or huntingtin. Treatment with Apt-1 restored proteostasis and inhibited cell death in a mouse model of proteinopathy induced by mutant tau(P301S). We conclude that pharmacological targeting of TRADD may represent a promising strategy for inhibiting cell death and restoring homeostasis to treat human diseases.
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Apoptosis/efectos de los fármacos , Homeostasis/efectos de los fármacos , Proteína de Dominio de Muerte Asociada a Receptor de TNF/antagonistas & inhibidores , Proteína de Dominio de Muerte Asociada a Receptor de TNF/metabolismo , Animales , Autofagia/efectos de los fármacos , Proteína 3 que Contiene Repeticiones IAP de Baculovirus/metabolismo , Beclina-1/química , Beclina-1/metabolismo , Bortezomib/antagonistas & inhibidores , Bortezomib/farmacología , Línea Celular , Humanos , Proteína Huntingtina/metabolismo , Proteínas Inhibidoras de la Apoptosis/metabolismo , Masculino , Ratones , Modelos Moleculares , Ovillos Neurofibrilares/metabolismo , Proteoma/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/química , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Proteína de Dominio de Muerte Asociada a Receptor de TNF/química , Proteína de Dominio de Muerte Asociada a Receptor de TNF/deficiencia , Factor 2 Asociado a Receptor de TNF/metabolismo , Ubiquitinación , alfa-Sinucleína/metabolismo , Proteínas tau/metabolismoRESUMEN
N6-methyladenosine (m6A) is an abundant modification in eukaryotic mRNA, regulating mRNA dynamics by influencing mRNA stability, splicing, export, and translation. However, the precise m6A regulating machinery still remains incompletely understood. Here we demonstrate that ZC3H13, a zinc-finger protein, plays an important role in modulating RNA m6A methylation in the nucleus. We show that knockdown of Zc3h13 in mouse embryonic stem cell significantly decreases global m6A level on mRNA. Upon Zc3h13 knockdown, a great majority of WTAP, Virilizer, and Hakai translocate to the cytoplasm, suggesting that Zc3h13 is required for nuclear localization of the Zc3h13-WTAP-Virilizer-Hakai complex, which is important for RNA m6A methylation. Finally, Zc3h13 depletion, as does WTAP, Virilizer, or Hakai, impairs self-renewal and triggers mESC differentiation. Taken together, our findings demonstrate that Zc3h13 plays a critical role in anchoring WTAP, Virilizer, and Hakai in the nucleus to facilitate m6A methylation and to regulate mESC self-renewal.
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Adenosina/análogos & derivados , Núcleo Celular/metabolismo , Proliferación Celular , Autorrenovación de las Células , Células Madre Embrionarias de Ratones/metabolismo , Proteínas Nucleares/metabolismo , Procesamiento Postranscripcional del ARN , ARN Mensajero/metabolismo , Regiones no Traducidas 3' , Transporte Activo de Núcleo Celular , Adenosina/metabolismo , Animales , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Proteínas de Ciclo Celular , Diferenciación Celular , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Regulación del Desarrollo de la Expresión Génica , Células HEK293 , Humanos , Metilación , Ratones , Proteínas Nucleares/genética , Factores de Empalme de ARN , Estabilidad del ARN , ARN Mensajero/genética , Proteínas de Unión al ARN , Transducción de Señal , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
The nasal epithelium is the initial entry portal and primary barrier to infection by all human coronaviruses (HCoVs). We utilize primary human nasal epithelial cells grown at air-liquid interface, which recapitulate the heterogeneous cellular population as well as mucociliary clearance functions of the in vivo nasal epithelium, to compare lethal [Severe acute respiratory syndrome (SARS)-CoV-2 and Middle East respiratory syndrome-CoV (MERS-CoV)] and seasonal (HCoV-NL63 and HCoV-229E) HCoVs. All four HCoVs replicate productively in nasal cultures, though replication is differentially modulated by temperature. Infections conducted at 33 °C vs. 37 °C (reflective of temperatures in the upper and lower airway, respectively) revealed that replication of both seasonal HCoVs (HCoV-NL63 and -229E) is significantly attenuated at 37 °C. In contrast, SARS-CoV-2 and MERS-CoV replicate at both temperatures, though SARS-CoV-2 replication is enhanced at 33 °C late in infection. These HCoVs also diverge significantly in terms of cytotoxicity induced following infection, as the seasonal HCoVs as well as SARS-CoV-2 cause cellular cytotoxicity as well as epithelial barrier disruption, while MERS-CoV does not. Treatment of nasal cultures with type 2 cytokine IL-13 to mimic asthmatic airways differentially impacts HCoV receptor availability as well as replication. MERS-CoV receptor DPP4 expression increases with IL-13 treatment, whereas ACE2, the receptor used by SARS-CoV-2 and HCoV-NL63, is down-regulated. IL-13 treatment enhances MERS-CoV and HCoV-229E replication but reduces that of SARS-CoV-2 and HCoV-NL63, reflecting the impact of IL-13 on HCoV receptor availability. This study highlights diversity among HCoVs during infection of the nasal epithelium, which is likely to influence downstream infection outcomes such as disease severity and transmissibility.
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COVID-19 , Coronaviridae , Coronavirus Humano 229E , Humanos , Interleucina-13/metabolismo , Estaciones del Año , SARS-CoV-2 , Células EpitelialesRESUMEN
TAK1 is a key modulator of both NF-κB signaling and RIPK1. In TNF signaling pathway, activation of TAK1 directly mediates the phosphorylation of IKK complex and RIPK1. In a search for small molecule activators of RIPK1-mediated necroptosis, we found R406/R788, two small molecule analogs that could promote sustained activation of TAK1. Treatment with R406 sensitized cells to TNF-mediated necroptosis and RIPK1-dependent apoptosis by promoting sustained RIPK1 activation. Using click chemistry and multiple biochemical binding assays, we showed that treatment with R406 promotes the activation of TAK1 by directly binding to TAK1, independent of its original target Syk kinase. Treatment with R406 promoted the ubiquitination of TAK1 and the interaction of activated TAK1 with ubiquitinated RIPK1. Finally, we showed that R406/R788 could promote the cancer-killing activities of TRAIL in vitro and in mouse models. Our studies demonstrate the possibility of developing small molecule TAK1 activators to potentiate the effect of TRAIL as anticancer therapies.
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Apoptosis , Neoplasias , Animales , Ratones , Muerte Celular , Citosol , Neoplasias/tratamiento farmacológico , Neoplasias/genética , UbiquitinaciónRESUMEN
Numerous putative glycosyltransferases (GTs) have been identified using bioinformatic approaches. However, demonstrating the activity of these GTs remains a challenge. Here, we describe the development of a rapid in vitro GT-array screening platform for activity of GTs. GT-arrays are generated by cell-free in vitro protein synthesis and binding using microplates precoated with a N-terminal Halo- or a C-terminal GST-tagged GT-encoding plasmid DNA and a capture antibody. These arrays are then used for screening of transferase activities and the reactions are monitored by a luminescence GLO assay. The products formed by these reactions can be analyzed directly from the microplates by mass spectrometry. Using this platform, a total of 280 assays were performed to screen 22 putative fucosyltransferases (FUTs) from family GT37 (seven from Arabidopsis and 15 from rice) for activity toward five acceptors: non-fucosylated tamarind xyloglucan (TXyG), arabinotriose (Ara3), non-fucosylated rhamnogalacturonan I (RG-I), and RG-II from the mur1-1 Arabidopsis mutant, and the celery RG-II monomer lacking Arap and MeFuc of chain B and l-Gal of chain A. Our screen showed that AtFUT2, AtFUT5, and AtFUT10 have activity toward RG-I, while AtFUT8 was active on RG-II. Five rice OsFUTs have XyG-FUT activity and four rice OsFUTs have activity toward Ara3. None of the putative OsFUTs were active on the RG-I and RG-II. However, promiscuity toward acceptors was observed for several FUTs. These findings extend our knowledge of cell wall polysaccharide fucosylation in plants. We believe that in vitro GT-array platform provides a valuable tool for cell wall biochemistry and other research fields.
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Pruebas de Enzimas , Fucosiltransferasas , Glicosiltransferasas , Proteínas de Plantas , Apium/enzimología , Apium/genética , Arabidopsis/enzimología , Arabidopsis/genética , Arabidopsis/metabolismo , Pared Celular/química , Pared Celular/enzimología , Pared Celular/metabolismo , Pruebas de Enzimas/instrumentación , Pruebas de Enzimas/métodos , Fucosiltransferasas/análisis , Fucosiltransferasas/clasificación , Fucosiltransferasas/metabolismo , Glicosiltransferasas/análisis , Glicosiltransferasas/metabolismo , Espectrometría de Masas , Oryza/enzimología , Proteínas de Plantas/análisis , Proteínas de Plantas/metabolismo , Polisacáridos/química , Polisacáridos/metabolismoRESUMEN
Human coronavirus (hCoV) OC43 is endemic to global populations and usually causes asymptomatic or mild upper respiratory tract illness. Here, we demonstrate the neutralization efficacy of isolated nanobodies from alpacas immunized with the S1B and S1C domain of the hCoV-OC43 spike glycoprotein. A total of 40 nanobodies bound to recombinant OC43 protein with affinities ranging from 1 to 149 nM. Two nanobodies WNb 293 and WNb 294 neutralized virus at 0.21 and 1.79 nM, respectively. Intranasal and intraperitoneal delivery of WNb 293 fused to an Fc domain significantly reduced nasal viral load in a mouse model of hCoV-OC43 infection. Using X-ray crystallography, we observed that WNb 293 bound to an epitope on the OC43 S1B domain, distal from the sialoglycan-binding site involved in host cell entry. This result suggests that neutralization mechanism of this nanobody does not involve disruption of glycan binding. Our work provides characterization of nanobodies against hCoV-OC43 that blocks virus entry and reduces viral loads in vivo and may contribute to future nanobody-based therapies for hCoV-OC43 infections. IMPORTANCE: The pandemic potential presented by coronaviruses has been demonstrated by the ongoing COVID-19 pandemic and previous epidemics caused by severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus. Outside of these major pathogenic coronaviruses, there are four endemic coronaviruses that infect humans: hCoV-OC43, hCoV-229E, hCoV-HKU1, and hCoV-NL63. We identified a collection of nanobodies against human coronavirus OC43 (hCoV-OC43) and found that two high-affinity nanobodies potently neutralized hCoV-OC43 at low nanomolar concentrations. Prophylactic administration of one neutralizing nanobody reduced viral loads in mice infected with hCoV-OC43, showing the potential for nanobody-based therapies for hCoV-OC43 infections.
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Anticuerpos Neutralizantes , Anticuerpos Antivirales , Camélidos del Nuevo Mundo , Infecciones por Coronavirus , Coronavirus Humano OC43 , Anticuerpos de Dominio Único , Glicoproteína de la Espiga del Coronavirus , Carga Viral , Animales , Anticuerpos de Dominio Único/inmunología , Ratones , Anticuerpos Neutralizantes/inmunología , Coronavirus Humano OC43/inmunología , Humanos , Anticuerpos Antivirales/inmunología , Camélidos del Nuevo Mundo/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/virología , Femenino , Epítopos/inmunología , Cristalografía por Rayos X , Internalización del Virus/efectos de los fármacos , Modelos Animales de Enfermedad , Ratones Endogámicos BALB CRESUMEN
BACKGROUND AND AIMS: Apoptosis Signal-regulating Kinase 1 (ASK1) is activated by various pathological stimuli and induces cell apoptosis through downstream p38 activation. We studied the effect of pharmacological ASK1 inhibition on cirrhosis and its sequelae using comprehensive preclinical in vivo and in vitro systems. APPROACH AND RESULTS: Short-term (4-6 wk) and long-term (24-44 wk) ASK1 inhibition using small molecule GS-444217 was tested in thioacetamide-induced and BALB/c. Mdr2-/- murine models of cirrhosis and HCC, and in vitro using primary hepatocyte cell death assays. Short-term GS-444217 therapy in both models strongly reduced phosphorylated p38, hepatocyte death, and fibrosis by up to 50%. Profibrogenic release of mitochondrial DAMP mitochondrial deoxyribonucleic acid from dying hepatocytes was blocked by ASK1 or p38 inhibition. Long-term (24 wk) therapy in BALBc.Mdr2 - / - model resulted in a moderate 25% reduction in bridging fibrosis, but not in net collagen deposition. Despite this, the development of cirrhosis was effectively prevented, with strongly reduced p21 + hepatocyte staining (by 72%), serum ammonia levels (by 46%), and portal pressure (average 6.07 vs. 8.53 mm Hg in controls). Extended ASK1 inhibition for 44 wk in aged BALB/c. Mdr2-/- mice resulted in markedly reduced tumor number and size by ~50% compared to the control group. CONCLUSIONS: ASK1 inhibition suppresses the profibrogenic release of mitochondrial deoxyribonucleic acid from dying hepatocytes in a p38-dependent manner and protects from liver fibrosis. Long-term ASK1 targeting resulted in diminished net antifibrotic effect, but the progression to liver cirrhosis and cancer in BALBc/ Mdr2- / - mice was effectively inhibited. These data support the clinical evaluation of ASK1 inhibitors in fibrotic liver diseases.
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Progresión de la Enfermedad , Hepatocitos , Cirrosis Hepática , Neoplasias Hepáticas , MAP Quinasa Quinasa Quinasa 5 , Ratones Endogámicos BALB C , Proteínas Quinasas p38 Activadas por Mitógenos , Animales , MAP Quinasa Quinasa Quinasa 5/antagonistas & inhibidores , MAP Quinasa Quinasa Quinasa 5/metabolismo , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Ratones , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/patología , Cirrosis Hepática/metabolismo , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Masculino , Tioacetamida/toxicidad , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Modelos Animales de EnfermedadRESUMEN
Amyloid fibril is an important pharmaceutical target for diagnostic and therapeutic treatment of neurodegenerative diseases. However, rational design of chemical compounds that interact with amyloid fibrils is unachievable due to the lack of mechanistic understanding of the ligand-fibril interaction. Here we used cryoelectron microscopy to survey the amyloid fibril-binding mechanism of a series of compounds including classic dyes, (pre)clinical imaging tracers and newly identified binders from high-throughput screening. We obtained clear densities of several compounds in complex with an α-synuclein fibril. These structures unveil the basic mechanism of the ligand-fibril interaction, which exhibits remarkable difference from the canonical ligand-protein interaction. In addition, we discovered a druggable pocket that is also conserved in the ex vivo α-synuclein fibrils from multiple system atrophy. Collectively, these findings expand our knowledge of protein-ligand interaction in the amyloid fibril state, which will enable rational design of amyloid binders in a medicinally beneficial way.
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Amiloide , alfa-Sinucleína , alfa-Sinucleína/química , Microscopía por Crioelectrón , Amiloide/química , LigandosRESUMEN
Middle East respiratory syndrome coronavirus (MERS-CoV) emerged into humans in 2012, causing highly lethal respiratory disease. The severity of disease may be, in part, because MERS-CoV is adept at antagonizing early innate immune pathwaysinterferon (IFN) production and signaling, protein kinase R (PKR), and oligoadenylate synthetase/ribonuclease L (OAS/RNase L)activated in response to viral double-stranded RNA (dsRNA) generated during genome replication. This is in contrast to severe acute respiratory syndrome CoV-2 (SARS-CoV-2), which we recently reported to activate PKR and RNase L and, to some extent, IFN signaling. We previously found that MERS-CoV accessory proteins NS4a (dsRNA binding protein) and NS4b (phosphodiesterase) could weakly suppress these pathways, but ablation of each had minimal effect on virus replication. Here we investigated the antagonist effects of the conserved coronavirus endoribonuclease (EndoU), in combination with NS4a or NS4b. Inactivation of EndoU catalytic activity alone in a recombinant MERS-CoV caused little if any effect on activation of the innate immune pathways during infection. However, infection with recombinant viruses containing combined mutations with inactivation of EndoU and deletion of NS4a or inactivation of the NS4b phosphodiesterase promoted robust activation of dsRNA-induced innate immune pathways. This resulted in at least tenfold attenuation of replication in human lungderived A549 and primary nasal cells. Furthermore, replication of these recombinant viruses could be rescued to the level of wild-type MERS-CoV by knockout of host immune mediators MAVS, PKR, or RNase L. Thus, EndoU and accessory proteins NS4a and NS4b together suppress dsRNA-induced innate immunity during MERS-CoV infection in order to optimize viral replication.
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COVID-19 , Infecciones por Coronavirus , Coronavirus del Síndrome Respiratorio de Oriente Medio , Infecciones por Coronavirus/inmunología , Endorribonucleasas/genética , Endorribonucleasas/metabolismo , Células Epiteliales/metabolismo , Humanos , Inmunidad Innata , Pulmón/metabolismo , Coronavirus del Síndrome Respiratorio de Oriente Medio/genética , Coronavirus del Síndrome Respiratorio de Oriente Medio/patogenicidad , Mucosa Nasal , SARS-CoV-2/patogenicidad , Endorribonucleasas Específicas de UridilatoRESUMEN
The conversion of thermodynamically inert CO2 into methanol holds immense promise for addressing the pressing environmental and energy challenges of our time. This article offers a succinct overview of the development of single-atom catalysts (SACs) for thermochemical hydrogenation of CO2 to methanol, encompassing research advancements, advantages, potential hurdles, and other essential aspects related to these catalysts. Our aim of this work is to provide a deeper understanding of the intricacies of the catalytic structures of the single-atom sites and their unique structure-activity relationships in catalyzing the conversion of CO2 to methanol. We also present insights into the optimal design of SACs, drawing from our own research and those of fellow scientists. This research thrust is poised to contribute significantly to the development of next-generation SACs, which are crucial in advancing the sustainable production of methanol from CO2.
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BACKGROUND AND AIMS: Cholangiocarcinoma (CCA) is a dreaded complication of primary sclerosing cholangitis (PSC), difficult to diagnose and associated with high mortality. Lack of animal models of CCA recapitulating the hepatic microenvironment of sclerosing cholangitis hinders development of novel treatments. Here we sought to develop such PSC-associated CCA model in mice. METHODS: Ten-week-old Mdr2-/- mice with congenital PSC-like disease, and healthy wild-type littermates were subjected to either modified retrograde biliary instillation or hydrodynamic tail vein injection of sleeping beauty transposon-transposase plasmid system with activated AKT (myr-AKT) and Yap (YapS127A) protooncogenes (SB AKT/YAP1). The role of TGFß was interrogated via ALK5 inhibitor (SB-525334) administration. Tumor phenotype, burden and desmoplastic reaction were analyzed histologically and via RNA-seq. RESULTS: While SB AKT/YAP1 plasmids via retrograde biliary injection caused tumors in Mdr2-/-, only 26.67% (4/15) of these tumors were CCA. Alternatively, hydrodynamic tail vein injection of SB AKT/YAP1 resulted in robust tumorigenesis in all fibrotic Mdr2-/- mice with high CCA burden compared to healthy mice. Tumors phenotypically resembled human CCA, expressed multiple CCA (but not hepatocellular carcinoma) markers, and exhibited a profound desmoplastic reaction. RNA-seq analysis revealed profound transcriptional changes in CCA evolving in PSC-like context, with specific alterations in multiple immune pathways. Pharmacological TGFß inhibition led to enhanced immune cell tumor infiltration, reduced tumor burden and suppressed desmoplastic collagen accumulation compared to placebo CONCLUSION: We established a new high-fidelity cholangiocarcinoma model in mice, termed SB CCA.Mdr2-/-, which recapitulates the increased susceptibility to CCA in the setting of biliary injury and fibrosis observed in PSC. Through transcriptomics and pharmacological studies, we show dysregulation of multiple immune pathways and TGFß signaling as potential drivers of CCA in PSC-like microenvironment. IMPACT AND IMPLICATIONS: There is a lack of animal models for primary sclerosing cholangitis (PSC) related cholangiocarcinoma (PSC-CCA). We have developed and characterized a new mouse model of PSC-CCA, termed SB CCA.Mdr2-/-, which features reliable tumor induction in PSC-like background of biliary injury and fibrosis. Global gene expression alterations were identified and standardized tools, including automated whole slide image analysis methodology for tumor burden and feature analysis, were established to enable systematic research into PSC-CCA biology and formal pre-clinical drug testing.
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BACKGROUND & AIMS: Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary liver cancer and is highly lethal. Clonorchis sinensis (C. sinensis) infection is an important risk factor for iCCA. Here we investigated the clinical impact and underlying molecular characteristics of C. sinensis infection-related iCCA. METHODS: We performed single-cell RNA sequencing, whole-exome sequencing, RNA sequencing, metabolomics and spatial transcriptomics in 251 patients with iCCA from three medical centers. Alterations in metabolism and the immune microenvironment of C. sinensis-related iCCAs were validated through an in vitro co-culture system and in a mouse model of iCCA. RESULTS: We revealed that C. sinensis infection was significantly associated with iCCA patients' overall survival and response to immunotherapy. Fatty acid biosynthesis and the expression of fatty acid synthase (FASN), a key enzyme catalyzing long-chain fatty acid synthesis, were significantly enriched in C. sinensis-related iCCAs. iCCA cell lines treated with excretory/secretory products of C. sinensis displayed elevated FASN and free fatty acids. The metabolic alteration of tumor cells was closely correlated with the enrichment of tumor-associated macrophage (TAM)-like macrophages and the impaired function of T cells, which led to formation of an immunosuppressive microenvironment and tumor progression. Spatial transcriptomics analysis revealed that malignant cells were in closer juxtaposition with TAM-like macrophages in C. sinensis-related iCCAs than non-C. sinensis-related iCCAs. Importantly, treatment with a FASN inhibitor significantly reversed the immunosuppressive microenvironment and enhanced anti-PD-1 efficacy in iCCA mouse models treated with excretory/secretory products from C. sinensis. CONCLUSIONS: We provide novel insights into metabolic alterations and the immune microenvironment in C. sinensis infection-related iCCAs. We also demonstrate that the combination of a FASN inhibitor with immunotherapy could be a promising strategy for the treatment of C. sinensis-related iCCAs. IMPACT AND IMPLICATIONS: Clonorchis sinensis (C. sinensis)-infected patients with intrahepatic cholangiocarcinoma (iCCA) have a worse prognosis and response to immunotherapy than non-C. sinensis-infected patients with iCCA. The underlying molecular characteristics of C. sinensis infection-related iCCAs remain unclear. Herein, we demonstrate that upregulation of FASN (fatty acid synthase) and free fatty acids in C. sinensis-related iCCAs leads to formation of an immunosuppressive microenvironment and tumor progression. Thus, administration of FASN inhibitors could significantly reverse the immunosuppressive microenvironment and further enhance the efficacy of anti-PD-1 against C. sinensis-related iCCAs.