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1.
Nature ; 629(8013): 803-809, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38593860

RESUMEN

Dielectric electrostatic capacitors1, because of their ultrafast charge-discharge, are desirable for high-power energy storage applications. Along with ultrafast operation, on-chip integration can enable miniaturized energy storage devices for emerging autonomous microelectronics and microsystems2-5. Moreover, state-of-the-art miniaturized electrochemical energy storage systems-microsupercapacitors and microbatteries-currently face safety, packaging, materials and microfabrication challenges preventing on-chip technological readiness2,3,6, leaving an opportunity for electrostatic microcapacitors. Here we report record-high electrostatic energy storage density (ESD) and power density, to our knowledge, in HfO2-ZrO2-based thin film microcapacitors integrated into silicon, through a three-pronged approach. First, to increase intrinsic energy storage, atomic-layer-deposited antiferroelectric HfO2-ZrO2 films are engineered near a field-driven ferroelectric phase transition to exhibit amplified charge storage by the negative capacitance effect7-12, which enhances volumetric ESD beyond the best-known back-end-of-the-line-compatible dielectrics (115 J cm-3) (ref. 13). Second, to increase total energy storage, antiferroelectric superlattice engineering14 scales the energy storage performance beyond the conventional thickness limitations of HfO2-ZrO2-based (anti)ferroelectricity15 (100-nm regime). Third, to increase the storage per footprint, the superlattices are conformally integrated into three-dimensional capacitors, which boosts the areal ESD nine times and the areal power density 170 times that of the best-known electrostatic capacitors: 80 mJ cm-2 and 300 kW cm-2, respectively. This simultaneous demonstration of ultrahigh energy density and power density overcomes the traditional capacity-speed trade-off across the electrostatic-electrochemical energy storage hierarchy1,16. Furthermore, the integration of ultrahigh-density and ultrafast-charging thin films within a back-end-of-the-line-compatible process enables monolithic integration of on-chip microcapacitors5, which can unlock substantial energy storage and power delivery performance for electronic microsystems17-19.

2.
Nature ; 605(7909): 349-356, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35477763

RESUMEN

Although circumstantial evidence supports enhanced Toll-like receptor 7 (TLR7) signalling as a mechanism of human systemic autoimmune disease1-7, evidence of lupus-causing TLR7 gene variants is lacking. Here we describe human systemic lupus erythematosus caused by a TLR7 gain-of-function variant. TLR7 is a sensor of viral RNA8,9 and binds to guanosine10-12. We identified a de novo, previously undescribed missense TLR7Y264H variant in a child with severe lupus and additional variants in other patients with lupus. The TLR7Y264H variant selectively increased sensing of guanosine and 2',3'-cGMP10-12, and was sufficient to cause lupus when introduced into mice. We show that enhanced TLR7 signalling drives aberrant survival of B cell receptor (BCR)-activated B cells, and in a cell-intrinsic manner, accumulation of CD11c+ age-associated B cells and germinal centre B cells. Follicular and extrafollicular helper T cells were also increased but these phenotypes were cell-extrinsic. Deficiency of MyD88 (an adaptor protein downstream of TLR7) rescued autoimmunity, aberrant B cell survival, and all cellular and serological phenotypes. Despite prominent spontaneous germinal-centre formation in Tlr7Y264H mice, autoimmunity was not ameliorated by germinal-centre deficiency, suggesting an extrafollicular origin of pathogenic B cells. We establish the importance of TLR7 and guanosine-containing self-ligands for human lupus pathogenesis, which paves the way for therapeutic TLR7 or MyD88 inhibition.


Asunto(s)
Mutación con Ganancia de Función , Lupus Eritematoso Sistémico , Receptor Toll-Like 7 , Animales , Autoinmunidad/genética , Linfocitos B , GMP Cíclico/análogos & derivados , Guanosina , Humanos , Lupus Eritematoso Sistémico/genética , Ratones , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/metabolismo , Receptor Toll-Like 7/genética , Receptor Toll-Like 7/metabolismo
3.
Nature ; 604(7904): 65-71, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35388197

RESUMEN

With the scaling of lateral dimensions in advanced transistors, an increased gate capacitance is desirable both to retain the control of the gate electrode over the channel and to reduce the operating voltage1. This led to a fundamental change in the gate stack in 2008, the incorporation of high-dielectric-constant HfO2 (ref. 2), which remains the material of choice to date. Here we report HfO2-ZrO2 superlattice heterostructures as a gate stack, stabilized with mixed ferroelectric-antiferroelectric order, directly integrated onto Si transistors, and scaled down to approximately 20 ångströms, the same gate oxide thickness required for high-performance transistors. The overall equivalent oxide thickness in metal-oxide-semiconductor capacitors is equivalent to an effective SiO2 thickness of approximately 6.5 ångströms. Such a low effective oxide thickness and the resulting large capacitance cannot be achieved in conventional HfO2-based high-dielectric-constant gate stacks without scavenging the interfacial SiO2, which has adverse effects on the electron transport and gate leakage current3. Accordingly, our gate stacks, which do not require such scavenging, provide substantially lower leakage current and no mobility degradation. This work demonstrates that ultrathin ferroic HfO2-ZrO2 multilayers, stabilized with competing ferroelectric-antiferroelectric order in the two-nanometre-thickness regime, provide a path towards advanced gate oxide stacks in electronic devices beyond conventional HfO2-based high-dielectric-constant materials.

4.
Am J Hum Genet ; 110(3): 419-426, 2023 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-36868206

RESUMEN

Australian Genomics is a national collaborative partnership of more than 100 organizations piloting a whole-of-system approach to integrating genomics into healthcare, based on federation principles. In the first five years of operation, Australian Genomics has evaluated the outcomes of genomic testing in more than 5,200 individuals across 19 rare disease and cancer flagship studies. Comprehensive analyses of the health economic, policy, ethical, legal, implementation and workforce implications of incorporating genomics in the Australian context have informed evidence-based change in policy and practice, resulting in national government funding and equity of access for a range of genomic tests. Simultaneously, Australian Genomics has built national skills, infrastructure, policy, and data resources to enable effective data sharing to drive discovery research and support improvements in clinical genomic delivery.


Asunto(s)
Genómica , Política de Salud , Humanos , Australia , Enfermedades Raras , Atención a la Salud
5.
J Allergy Clin Immunol ; 153(4): 1125-1139, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38072195

RESUMEN

BACKGROUND: Inborn errors of immunity (IEI) often lack specific disease models and personalized management. Signal transducer and activator of transcription (STAT)-1 gain of function (GoF) is such example of an IEI with diverse clinical phenotype with unclear pathomechanisms and unpredictable response to therapy. Limitations in obtaining fresh samples for functional testing and research further highlights the need for patient-specific ex vivo platforms. OBJECTIVE: Using STAT1-GoF as an example IEI, we investigated the potential of patient-derived expanded potential stem cells (EPSC) as an ex vivo platform for disease modeling and personalized treatment. METHODS: We generated EPSC derived from individual STAT1-GoF patients. STAT1 mutations were confirmed with Sanger sequencing. Functional testing including STAT1 phosphorylation/dephosphorylation and gene expression with or without Janus activating kinase inhibitors were performed. Functional tests were repeated on EPSC lines with GoF mutations repaired by CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) editing. RESULTS: EPSC were successfully reprogrammed from STAT1-GoF patients and expressed the same pluripotent makers as controls, with distinct morphologic differences. Patient-derived EPSC recapitulated the functional abnormalities of index STAT1-GoF patients with STAT1 hyperphosphorylation and increased expression of STAT1 and its downstream genes (IRF1, APOL6, and OAS1) after IFN-γ stimulation. Addition of ruxolitinib and baricitinib inhibited STAT1 hyperactivation in STAT1-GoF EPSC in a dose-dependent manner, which was not observed with tofacitinib. Corrected STAT1 phosphorylation and downstream gene expression were observed among repaired STAT1-GoF EPSC cell lines. CONCLUSION: This proof-of-concept study demonstrates the potential of our patient-derived EPSC platform to model STAT1-GoF. We propose this platform when researching, recapitulating, and repairing other IEI in the future.


Asunto(s)
Mutación con Ganancia de Función , Factor de Transcripción STAT1 , Células Madre , Humanos , Mutación , Fosforilación , Factor de Transcripción STAT1/genética , Factor de Transcripción STAT1/metabolismo , Células Madre/inmunología , Células Madre/metabolismo
6.
Artículo en Inglés | MEDLINE | ID: mdl-38710235

RESUMEN

BACKGROUND: LCP1 encodes L-plastin, an actin-bundling protein primarily expressed in hematopoietic cells. In mouse and fish models, LCP1 deficiency has been shown to result in hematologic and immune defects. OBJECTIVE: This study aimed to determine the nature of a human inborn error of immunity resulting from a novel genetic variant of LCP1. METHODS: We performed genetic, protein, and cellular analysis of PBMCs from a kindred with apparent autosomal dominant immune deficiency. We identified a candidate causal mutation in LCP1, which we evaluated by engineering the orthologous mutation in mice and Jurkat cells. RESULTS: A splice-site variant in LCP1 segregated with lymphopenia, neutropenia, and thrombocytopenia. The splicing defect resulted in at least 2 aberrant transcripts, producing an in-frame deletion of 24 nucleotides, and a frameshift deletion of exon 8. Cellular analysis of the kindred revealed a proportionate reduction of T and B cells and a mild expansion of transitional B cells. Similarly, mice carrying the orthologous genetic variant exhibited the same in-frame aberrant transcript, reduced expression Lcp1 and gene dose-dependent leukopenia, mild thrombocytopenia, and lymphopenia, with a significant reduction of T-cell populations. Functional analysis revealed that LCP1c740-1G>A confers a defect in platelet development and function with aberrant spreading on collagen. Immunologic analysis revealed defective actin organization in T cells, reduced migration of PBMCs from patients, splenocytes from mutant mice, and a mutant Jurkat cell line in response to CXCL12; impaired germinal center B-cell expansion after immunization; and reduced cytokinesis during T cell proliferation. CONCLUSIONS: We describe a unique human hematopoietic defect affecting neutrophils, lymphocytes, and platelets arising from partial LCP1 deficiency.

7.
Nat Methods ; 18(7): 771-774, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34168373

RESUMEN

We develop an automatic method for synaptic partner identification in insect brains and use it to predict synaptic partners in a whole-brain electron microscopy dataset of the fruit fly. The predictions can be used to infer a connectivity graph with high accuracy, thus allowing fast identification of neural pathways. To facilitate circuit reconstruction using our results, we develop CIRCUITMAP, a user interface add-on for the circuit annotation tool CATMAID.


Asunto(s)
Encéfalo/fisiología , Procesamiento de Imagen Asistido por Computador/métodos , Sinapsis/fisiología , Animales , Encéfalo/citología , Bases de Datos Factuales , Drosophila melanogaster , Microscopía Electrónica , Vías Nerviosas
8.
Curr Issues Mol Biol ; 45(7): 5981-6002, 2023 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-37504294

RESUMEN

The pathogenesis of childhood-onset systemic lupus erythematosus (cSLE) is complex and not fully understood. It involves three key factors: genetic risk factors, epigenetic mechanisms, and environmental triggers. Genetic factors play a significant role in the development of the disease, particularly in younger individuals. While cSLE has traditionally been considered a polygenic disease, it is now recognized that in rare cases, a single gene mutation can lead to the disease. Although these cases are uncommon, they provide valuable insights into the disease mechanism, enhance our understanding of pathogenesis and immune tolerance, and facilitate the development of targeted treatment strategies. This review aims to provide a comprehensive overview of both monogenic and polygenic SLE, emphasizing the implications of specific genes in disease pathogenesis. By conducting a thorough analysis of the genetic factors involved in SLE, we can improve our understanding of the underlying mechanisms of the disease. Furthermore, this knowledge may contribute to the identification of effective biomarkers and the selection of appropriate therapies for individuals with SLE.

9.
Clin Immunol ; 252: 109646, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37209807

RESUMEN

BACKGROUND: Kikuchi-Fujimoto disease (KFD) is a self-limited inflammatory disease of unknown pathogenesis. Familial cases have been described and defects in classical complement components C1q and C4 have been identified in some patients. MATERIAL AND METHODS: We describe genetic and immune investigations of a 16 years old Omani male, a product of consanguineous marriage, who presented with typical clinical and histological features of KFD. RESULTS: We identified a novel homozygous single base deletion in C1S (c.330del; p. Phe110LeufsTer23) resulting in a defect in the classical complement pathway. The patient was negative for all serological markers of SLE. In contrast, two female siblings (also homozygous for the C1S mutation), one has autoimmune thyroid disease (Hashimoto thyroiditis) and a positive ANA and the other sibling has serology consistent with SLE. CONCLUSION: We report the first association between C1s deficiency and KFD.


Asunto(s)
Linfadenitis Necrotizante Histiocítica , Adolescente , Humanos , Masculino , Complemento C1s/genética , Linfadenitis Necrotizante Histiocítica/genética , Linfadenitis Necrotizante Histiocítica/complicaciones , Linfadenitis Necrotizante Histiocítica/patología , Mutación con Pérdida de Función
10.
Am J Hum Genet ; 107(2): 175-182, 2020 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-32763188

RESUMEN

Expanded carrier screening (ECS) for recessive monogenic diseases requires prior knowledge of genomic variation, including DNA variants that cause disease. The composition of pathogenic variants differs greatly among human populations, but historically, research about monogenic diseases has focused mainly on people with European ancestry. By comparison, less is known about pathogenic DNA variants in people from other parts of the world. Consequently, inclusion of currently underrepresented Indigenous and other minority population groups in genomic research is essential to enable equitable outcomes in ECS and other areas of genomic medicine. Here, we discuss this issue in relation to the implementation of ECS in Australia, which is currently being evaluated as part of the national Government's Genomics Health Futures Mission. We argue that significant effort is required to build an evidence base and genomic reference data so that ECS can bring significant clinical benefit for many Aboriginal and/or Torres Strait Islander Australians. These efforts are essential steps to achieving the Australian Government's objectives and its commitment "to leveraging the benefits of genomics in the health system for all Australians." They require culturally safe, community-led research and community involvement embedded within national health and medical genomics programs to ensure that new knowledge is integrated into medicine and health services in ways that address the specific and articulated cultural and health needs of Indigenous people. Until this occurs, people who do not have European ancestry are at risk of being, in relative terms, further disadvantaged.


Asunto(s)
Metagenómica/métodos , Grupos de Población/genética , Australia , Variación Genética/genética , Humanos
11.
PLoS Pathog ; 17(6): e1009683, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34166473

RESUMEN

COVID-19 is a global crisis of unimagined dimensions. Currently, Remedesivir is only fully licensed FDA therapeutic. A major target of the vaccine effort is the SARS-CoV-2 spike-hACE2 interaction, and assessment of efficacy relies on time consuming neutralization assay. Here, we developed a cell fusion assay based upon spike-hACE2 interaction. The system was tested by transient co-transfection of 293T cells, which demonstrated good correlation with standard spike pseudotyping for inhibition by sera and biologics. Then established stable cell lines were very well behaved and gave even better correlation with pseudotyping results, after a short, overnight co-incubation. Results with the stable cell fusion assay also correlated well with those of a live virus assay. In summary we have established a rapid, reliable, and reproducible cell fusion assay that will serve to complement the other neutralization assays currently in use, is easy to implement in most laboratories, and may serve as the basis for high throughput screens to identify inhibitors of SARS-CoV-2 virus-cell binding and entry.


Asunto(s)
Enzima Convertidora de Angiotensina 2/metabolismo , Bioensayo/métodos , COVID-19/virología , Receptores de Coronavirus/metabolismo , SARS-CoV-2/fisiología , Glicoproteína de la Espiga del Coronavirus/metabolismo , Enzima Convertidora de Angiotensina 2/genética , COVID-19/sangre , Fusión Celular , Células HEK293 , Humanos , Receptores de Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/genética , Transfección , Acoplamiento Viral
12.
Harm Reduct J ; 20(1): 110, 2023 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-37587466

RESUMEN

BACKGROUND: The opioid crisis continues in full force, as physicians and caregivers are desperate for resources to help patients with opioid use and chronic pain disorders find safer and more accessible non-opioid tools. MAIN BODY: The purpose of this article is to review the current state of the opioid epidemic; the shifting picture of cannabinoids; and the research, policy, and current events that make opioid risk reduction an urgent public health challenge. The provided table contains an evidence-based clinical framework for the utilization of cannabinoids to treat patients with chronic pain who are dependent on opioids, seeking alternatives to opioids, and tapering opioids. CONCLUSION: Based on a comprehensive review of the literature and epidemiological evidence to date, cannabinoids stand to be one of the most interesting, safe, and accessible tools available to attenuate the devastation resulting from the misuse and abuse of opioid narcotics. Considering the urgency of the opioid epidemic and broadening of cannabinoid accessibility amidst absent prescribing guidelines, the authors recommend use of this clinical framework in the contexts of both clinical research continuity and patient care.


Asunto(s)
Dolor Crónico , Epidemias , Humanos , Analgésicos Opioides/uso terapéutico , Epidemia de Opioides , Dolor Crónico/tratamiento farmacológico , Narcóticos
13.
Int J Sport Nutr Exerc Metab ; 33(5): 282-290, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37414403

RESUMEN

Previous observations demonstrate New Zealand blackcurrant (NZBC) extract to alter cardiovascular responses at rest without prior exercise. However, the prolonged effects of NZBC on blood pressure and heart rate variability following exercise are not known. Participants (n15 [five women], age: 31 ± 9 years, maximal oxygen uptake: 44 ± 9 ml·kg-1·min-1) undertook a control condition of 2 hr of lying supine rest. Subsequently, in a double-blind, placebo (PLA)-controlled, randomized crossover design participants completed 1 hr of treadmill exercise at 50% maximal oxygen uptake followed by 2-hr supine rest with blood pressure and heart rate variability measurement following a 7-day intake of NZBC and PLA. With NZBC, there was an increase in average fat oxidation (NZBC: 0.24 ± 0.11 vs. PLA: 0.17 ± 0.11 g/min, p = .005), and larger high-frequency relative power during the exercise (p = .037). In the 2-hr rest period, delta change for systolic pressure was larger with NZBC than PLA (Control vs. NZBC: -5.6 ± 6.4, Control vs. PLA: -3.5 ± 6.0 mmHg, p = .033) but was not different for diastolic or mean arterial pressure. There were no alterations in heart rate variabilities during the 2 hr following the exercise with NZBC. A 7-day intake of NZBC causes a larger postexercise hypotension response in young, physically active men and women following 1 hr of treadmill exercise at 50% maximal oxygen uptake.


Asunto(s)
Hipotensión Posejercicio , Ribes , Masculino , Humanos , Femenino , Adulto Joven , Adulto , Nueva Zelanda , Extractos Vegetales , Frecuencia Cardíaca , Presión Sanguínea , Consumo de Oxígeno , Oxígeno , Poliésteres/farmacología
14.
Can Vet J ; 64(9): 833-838, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37663020

RESUMEN

Although cancer of unknown primary origin (CUP) is well-described in the human literature, it is not as well-understood within veterinary medicine. This case report represents one of few focused on describing CUP in a dog. Key clinical message: Metastatic CUP should be considered as a differential diagnosis despite being a rare disease entity that is infrequently reported within the veterinary literature.


Carcinome métastatique d'origine inconnue chez un chien. Bien que le cancer d'origine primaire inconnue (CUP) soit bien décrit dans la littérature humaine, il n'est pas aussi bien compris en médecine vétérinaire. Ce rapport de cas représente l'un des rares à s'intéresser à la description du CUP chez un chien.Message clinique clé:Le CUP métastatique doit être considéré comme un diagnostic différentiel bien qu'il s'agisse d'une entité de maladie rare rarement rapportée dans la littérature vétérinaire.(Traduit par Dr Serge Messier).


Asunto(s)
Carcinoma , Neoplasias Primarias Desconocidas , Animales , Perros , Diagnóstico Diferencial , Carcinoma/veterinaria , Neoplasias Primarias Desconocidas/veterinaria
15.
J Biol Chem ; 296: 100045, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33465707

RESUMEN

The mammalian apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3 (APOBEC3 or A3) family of cytidine deaminases restrict viral infections by mutating viral DNA and impeding reverse transcription. To overcome this antiviral activity, most lentiviruses express a viral accessory protein called the virion infectivity factor (Vif), which recruits A3 proteins to cullin-RING E3 ubiquitin ligases such as cullin-5 (Cul5) for ubiquitylation and subsequent proteasomal degradation. Although Vif proteins from primate lentiviruses such as HIV-1 utilize the transcription factor core-binding factor subunit beta as a noncanonical cofactor to stabilize the complex, the maedi-visna virus (MVV) Vif hijacks cyclophilin A (CypA) instead. Because core-binding factor subunit beta and CypA are both highly conserved among mammals, the requirement for two different cellular cofactors suggests that these two A3-targeting Vif proteins have different biochemical and structural properties. To investigate this topic, we used a combination of in vitro biochemical assays and in vivo A3 degradation assays to study motifs required for the MVV Vif to bind zinc ion, Cul5, and the cofactor CypA. Our results demonstrate that although some common motifs between the HIV-1 Vif and MVV Vif are involved in recruiting Cul5, different determinants in the MVV Vif are required for cofactor binding and stabilization of the E3 ligase complex, such as the zinc-binding motif and N- and C-terminal regions of the protein. Results from this study advance our understanding of the mechanism of MVV Vif recruitment of cellular factors and the evolution of lentiviral Vif proteins.


Asunto(s)
Virus Visna-Maedi/metabolismo , Productos del Gen vif del Virus de la Inmunodeficiencia Humana/metabolismo , Secuencia de Aminoácidos , Proteínas Cullin/metabolismo , Ciclofilina A/metabolismo , Unión Proteica , Dominios Proteicos , Proteolisis , Zinc/metabolismo , Productos del Gen vif del Virus de la Inmunodeficiencia Humana/química
16.
Clin Immunol ; 236: 108938, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35121105

RESUMEN

Many patients with immunodeficiencies require lifelong immunoglobulin replacement therapy (IgRT). In a multicenter, randomized, open-label, crossover, non-inferiority 3-month-trial, we compared the impact of the subcutaneous immunoglobulin Gammanorm® administered via pump or syringe (rapid push). Primary endpoint was the life quality index (LQI), secondary endpoints were QoL (SF36v2), satisfaction (TSQM-11), disease and treatment burden (PRISM), incidence of infections and adverse events (AE), treatment costs, and IgG levels. 28/30 patients completed the study. Most of the endpoints were comparable. Drug administrations with rapid push were more frequent, but reduced total time expenditure and some costs. Of the TSQM-11/LQI/SF36 components only "treatment interference with daily activities" was superior with pump and two QoL domains with rapid push. Both delivery devices showed favorable safety. Rapid push was preferred by 34.5% of patients. It proved to be an efficacious and cost-effective alternative to pumps adding to patient choice and increasing flexibility during long-term IgRT.


Asunto(s)
Síndromes de Inmunodeficiencia , Calidad de Vida , Adulto , Humanos , Inmunización Pasiva , Inmunoglobulina G , Síndromes de Inmunodeficiencia/terapia , Infusiones Subcutáneas
17.
Immunity ; 38(4): 669-80, 2013 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-23583642

RESUMEN

Accumulation of T follicular helper (Tfh) cells and proinflammatory cytokines drive autoantibody-mediated diseases. The RNA-binding protein Roquin-1 (Rc3h1) represses the inducible costimulator ICOS and interferon-γ (IFN-γ) in T cells to prevent Tfh cell accumulation. Unlike Rc3h1(san) mice with a mutation in the ROQ domain of Roquin-1, mice lacking the protein, paradoxically do not display increased Tfh cells. Here we have analyzed mice with mutations that eliminate the RING domain from Roquin-1 or its paralog, Roquin-2 (Rc3h2). RING or ROQ mutations both disrupted Icos mRNA regulation by Roquin-1, but, unlike the ROQ mutant that still occupied mRNA-regulating stress granules, RING-deficient Roquin-1 failed to localize to stress granules and allowed Roquin-2 to compensate in the repression of ICOS and Tfh cells. These paralogs also targeted tumor necrosis factor (TNF) in nonlymphoid cells, ameliorating autoantibody-induced arthritis. The Roquin family emerges as a posttranscriptional brake in the adaptive and innate phases of antibody responses.


Asunto(s)
Proteína Coestimuladora de Linfocitos T Inducibles/metabolismo , ARN Mensajero/metabolismo , Proteínas Represoras/metabolismo , Linfocitos T Colaboradores-Inductores/inmunología , Factor de Necrosis Tumoral alfa/inmunología , Ubiquitina-Proteína Ligasas/metabolismo , Inmunidad Adaptativa/genética , Animales , Formación de Anticuerpos/genética , Línea Celular , Inmunidad Innata/genética , Ratones , Ratones Mutantes , Mutación/genética , Dominios RING Finger/genética , Proteínas Represoras/genética , Ubiquitina-Proteína Ligasas/genética
18.
Immunity ; 39(4): 770-81, 2013 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-24138884

RESUMEN

Follicular B helper T (Tfh) cells support high affinity and long-term antibody responses. Here we found that within circulating CXCR5⁺ CD4⁺ T cells in humans and mice, the CCR7(lo)PD-1(hi) subset has a partial Tfh effector phenotype, whereas CCR7(hi)PD-1(lo) cells have a resting phenotype. The circulating CCR7(lo)PD-1(hi) subset was indicative of active Tfh differentiation in lymphoid organs and correlated with clinical indices in autoimmune diseases. Thus the CCR7(lo)PD-1(hi) subset provides a biomarker to monitor protective antibody responses during infection or vaccination and pathogenic antibody responses in autoimmune diseases. Differentiation of both CCR7(hi)PD-1(lo) and CCR7(lo)PD-1(hi) subsets required ICOS and BCL6, but not SAP, suggesting that circulating CXCR5⁺ helper T cells are primarily generated before germinal centers. Upon antigen reencounter, CCR7(lo)PD-1(hi) CXCR5⁺ precursors rapidly differentiate into mature Tfh cells to promote antibody responses. Therefore, circulating CCR7(lo)PD-1(hi) CXCR5⁺ CD4⁺ T cells are generated during active Tfh differentiation and represent a new mechanism of immunological early memory.


Asunto(s)
Anticuerpos/inmunología , Memoria Inmunológica , Receptor de Muerte Celular Programada 1/inmunología , Receptores CXCR5/inmunología , Receptores CXCR/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Antígenos/inmunología , Linfocitos B/inmunología , Linfocitos B/patología , Linfocitos B/virología , Diferenciación Celular , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/inmunología , Expresión Génica , Centro Germinal/inmunología , Centro Germinal/patología , Centro Germinal/virología , Humanos , Inmunidad Humoral , Inmunofenotipificación , Proteína Coestimuladora de Linfocitos T Inducibles/genética , Proteína Coestimuladora de Linfocitos T Inducibles/inmunología , Ratones , Receptor de Muerte Celular Programada 1/genética , Proteínas Proto-Oncogénicas c-bcl-6 , Receptores CXCR/genética , Receptores CXCR5/genética , Linfocitos T Colaboradores-Inductores/patología , Linfocitos T Colaboradores-Inductores/virología
19.
J Org Chem ; 87(18): 12250-12256, 2022 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-36067340

RESUMEN

The formation of highly substituted cyclopentenols was developed using a Claisen-Sakurai reaction. Both elements of the reaction can be performed in a one-pot sequence that provides the corresponding cyclized products in high stereoselectivity. The stereochemical outcome is defined by a combination of Claisen stereospecificity and stereoelectronic effects in the Sakurai cyclization that promotes reactivity via an anti-SE' antiperiplanar transition state. This was determined by examination of the product stereochemistry and through detailed DFT analysis.


Asunto(s)
Estereoisomerismo , Ciclización
20.
J Infect Dis ; 223(1): 10-14, 2021 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-33009908

RESUMEN

Estimates of seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies have been hampered by inadequate assay sensitivity and specificity. Using an enzyme-linked immunosorbent assay-based approach that combines data about immunoglobulin G responses to both the nucleocapsid and spike receptor binding domain antigens, we show that excellent sensitivity and specificity can be achieved. We used this assay to assess the frequency of virus-specific antibodies in a cohort of elective surgery patients in Australia and estimated seroprevalence in Australia to be 0.28% (95% Confidence Interval, 0-1.15%). These data confirm the low level of transmission of SARS-CoV-2 in Australia before July 2020 and validate the specificity of our assay.


Asunto(s)
Anticuerpos Antivirales/análisis , COVID-19/diagnóstico , Ensayo de Inmunoadsorción Enzimática , Estudios Seroepidemiológicos , Antígenos Virales/inmunología , Australia , COVID-19/inmunología , Proteínas de la Nucleocápside de Coronavirus/inmunología , Humanos , Inmunoglobulina G/análisis , Fosfoproteínas/inmunología , Sensibilidad y Especificidad , Glicoproteína de la Espiga del Coronavirus/inmunología
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