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1.
Cell ; 185(6): 1025-1040.e14, 2022 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-35148837

RESUMO

During the SARS-CoV-2 pandemic, novel and traditional vaccine strategies have been deployed globally. We investigated whether antibodies stimulated by mRNA vaccination (BNT162b2), including third-dose boosting, differ from those generated by infection or adenoviral (ChAdOx1-S and Gam-COVID-Vac) or inactivated viral (BBIBP-CorV) vaccines. We analyzed human lymph nodes after infection or mRNA vaccination for correlates of serological differences. Antibody breadth against viral variants is lower after infection compared with all vaccines evaluated but improves over several months. Viral variant infection elicits variant-specific antibodies, but prior mRNA vaccination imprints serological responses toward Wuhan-Hu-1 rather than variant antigens. In contrast to disrupted germinal centers (GCs) in lymph nodes during infection, mRNA vaccination stimulates robust GCs containing vaccine mRNA and spike antigen up to 8 weeks postvaccination in some cases. SARS-CoV-2 antibody specificity, breadth, and maturation are affected by imprinting from exposure history and distinct histological and antigenic contexts in infection compared with vaccination.


Assuntos
Anticorpos Antivirais , Vacina BNT162 , COVID-19 , Centro Germinativo , Antígenos Virais , COVID-19/prevenção & controle , Humanos , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus , Vacinação
2.
Nat Immunol ; 25(1): 41-53, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38036767

RESUMO

Bacille Calmette-Guérin (BCG) vaccination can confer nonspecific protection against heterologous pathogens. However, the underlying mechanisms remain mysterious. We show that mice vaccinated intravenously with BCG exhibited reduced weight loss and/or improved viral clearance when challenged with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 B.1.351) or PR8 influenza. Protection was first evident between 14 and 21 d post-vaccination and lasted ∼3 months. Notably, BCG induced a biphasic innate response and robust antigen-specific type 1 helper T cell (TH1 cell) responses in the lungs. MyD88 signaling was essential for innate and TH1 cell responses, and protection against SARS-CoV-2. Depletion of CD4+ T cells or interferon (IFN)-γ activity before infection obliterated innate activation and protection. Single-cell and spatial transcriptomics revealed CD4-dependent expression of IFN-stimulated genes in lung myeloid and epithelial cells. Notably, BCG also induced protection against weight loss after mouse-adapted SARS-CoV-2 BA.5, SARS-CoV and SHC014 coronavirus infections. Thus, BCG elicits integrated organ immunity, where CD4+ T cells feed back on tissue myeloid and epithelial cells to imprint prolonged and broad innate antiviral resistance.


Assuntos
Imunidade Adaptativa , Vacina BCG , Animais , Camundongos , Humanos , Retroalimentação , Vacinação , Redução de Peso , Antivirais , Imunidade Inata
3.
Cell ; 184(15): 3915-3935.e21, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34174187

RESUMO

Emerging evidence indicates a fundamental role for the epigenome in immunity. Here, we mapped the epigenomic and transcriptional landscape of immunity to influenza vaccination in humans at the single-cell level. Vaccination against seasonal influenza induced persistently diminished H3K27ac in monocytes and myeloid dendritic cells (mDCs), which was associated with impaired cytokine responses to Toll-like receptor stimulation. Single-cell ATAC-seq analysis revealed an epigenomically distinct subcluster of monocytes with reduced chromatin accessibility at AP-1-targeted loci after vaccination. Similar effects were observed in response to vaccination with the AS03-adjuvanted H5N1 pandemic influenza vaccine. However, this vaccine also stimulated persistently increased chromatin accessibility at interferon response factor (IRF) loci in monocytes and mDCs. This was associated with elevated expression of antiviral genes and heightened resistance to the unrelated Zika and Dengue viruses. These results demonstrate that vaccination stimulates persistent epigenomic remodeling of the innate immune system and reveal AS03's potential as an epigenetic adjuvant.


Assuntos
Epigenômica , Imunidade/genética , Vacinas contra Influenza/genética , Vacinas contra Influenza/imunologia , Análise de Célula Única , Transcrição Gênica , Vacinação , Adolescente , Adulto , Antibacterianos/farmacologia , Antígenos CD34/metabolismo , Antivirais/farmacologia , Reprogramação Celular , Cromatina/metabolismo , Citocinas/biossíntese , Combinação de Medicamentos , Feminino , Regulação da Expressão Gênica , Histonas/metabolismo , Humanos , Imunidade Inata/genética , Virus da Influenza A Subtipo H5N1/efeitos dos fármacos , Virus da Influenza A Subtipo H5N1/imunologia , Interferon Tipo I/metabolismo , Masculino , Células Mieloides/metabolismo , Polissorbatos/farmacologia , Esqualeno/farmacologia , Receptores Toll-Like/metabolismo , Fator de Transcrição AP-1/metabolismo , Transcriptoma/genética , Adulto Jovem , alfa-Tocoferol/farmacologia
4.
Nat Immunol ; 24(2): 337-348, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36577930

RESUMO

Our previous study using systems vaccinology identified an association between the sterol regulatory binding protein (SREBP) pathway and humoral immune response to vaccination in humans. To investigate the role of SREBP signaling in modulating immune responses, we generated mice with B cell- or CD11c+ antigen-presenting cell (APC)-specific deletion of SCAP, an essential regulator of SREBP signaling. Ablation of SCAP in CD11c+ APCs had no effect on immune responses. In contrast, SREBP signaling in B cells was critical for antibody responses, as well as the generation of germinal centers,memory B cells and bone marrow plasma cells. SREBP signaling was required for metabolic reprogramming in activated B cells. Upon mitogen stimulation, SCAP-deficient B cells could not proliferate and had decreased lipid rafts. Deletion of SCAP in germinal center B cells using AID-Cre decreased lipid raft content and cell cycle progression. These studies provide mechanistic insights coupling sterol metabolism with the quality and longevity of humoral immunity.


Assuntos
Proteínas de Transporte , Linfoma de Células B , Esteróis , Animais , Humanos , Camundongos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Esteróis/metabolismo , Linfoma de Células B/metabolismo
5.
Nat Immunol ; 23(4): 543-555, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35288714

RESUMO

Despite the success of the BNT162b2 mRNA vaccine, the immunological mechanisms that underlie its efficacy are poorly understood. Here we analyzed the innate and adaptive responses to BNT162b2 in mice, and show that immunization stimulated potent antibody and antigen-specific T cell responses, as well as strikingly enhanced innate responses after secondary immunization, which was concurrent with enhanced serum interferon (IFN)-γ levels 1 d following secondary immunization. Notably, we found that natural killer cells and CD8+ T cells in the draining lymph nodes are the major producers of this circulating IFN-γ. Analysis of knockout mice revealed that induction of antibody and T cell responses to BNT162b2 was not dependent on signaling via Toll-like receptors 2, 3, 4, 5 and 7 nor inflammasome activation, nor the necroptosis or pyroptosis cell death pathways. Rather, the CD8+ T cell response induced by BNT162b2 was dependent on type I interferon-dependent MDA5 signaling. These results provide insights into the molecular mechanisms by which the BNT162b2 vaccine stimulates immune responses.


Assuntos
Linfócitos T CD8-Positivos , Vacinas , Imunidade Adaptativa , Animais , Vacina BNT162 , Humanos , Imunidade Inata , Camundongos , Vacinas Sintéticas , Vacinas de mRNA
6.
Immunity ; 56(4): 864-878.e4, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-36996809

RESUMO

T cells are a critical component of the response to SARS-CoV-2, but their kinetics after infection and vaccination are insufficiently understood. Using "spheromer" peptide-MHC multimer reagents, we analyzed healthy subjects receiving two doses of the Pfizer/BioNTech BNT162b2 vaccine. Vaccination resulted in robust spike-specific T cell responses for the dominant CD4+ (HLA-DRB1∗15:01/S191) and CD8+ (HLA-A∗02/S691) T cell epitopes. Antigen-specific CD4+ and CD8+ T cell responses were asynchronous, with the peak CD4+ T cell responses occurring 1 week post the second vaccination (boost), whereas CD8+ T cells peaked 2 weeks later. These peripheral T cell responses were elevated compared with COVID-19 patients. We also found that previous SARS-CoV-2 infection resulted in decreased CD8+ T cell activation and expansion, suggesting that previous infection can influence the T cell response to vaccination.


Assuntos
COVID-19 , Vacinas , Humanos , Linfócitos T CD8-Positivos , Vacina BNT162 , SARS-CoV-2 , Vacinação , Anticorpos Antivirais
7.
Nature ; 596(7872): 410-416, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34252919

RESUMO

The emergency use authorization of two mRNA vaccines in less than a year from the emergence of SARS-CoV-2 represents a landmark in vaccinology1,2. Yet, how mRNA vaccines stimulate the immune system to elicit protective immune responses is unknown. Here we used a systems vaccinology approach to comprehensively profile the innate and adaptive immune responses of 56 healthy volunteers who were vaccinated with the Pfizer-BioNTech mRNA vaccine (BNT162b2). Vaccination resulted in the robust production of neutralizing antibodies against the wild-type SARS-CoV-2 (derived from 2019-nCOV/USA_WA1/2020) and, to a lesser extent, the B.1.351 strain, as well as significant increases in antigen-specific polyfunctional CD4 and CD8 T cells after the second dose. Booster vaccination stimulated a notably enhanced innate immune response as compared to primary vaccination, evidenced by (1) a greater frequency of CD14+CD16+ inflammatory monocytes; (2) a higher concentration of plasma IFNγ; and (3) a transcriptional signature of innate antiviral immunity. Consistent with these observations, our single-cell transcriptomics analysis demonstrated an approximately 100-fold increase in the frequency of a myeloid cell cluster enriched in interferon-response transcription factors and reduced in AP-1 transcription factors, after secondary immunization. Finally, we identified distinct innate pathways associated with CD8 T cell and neutralizing antibody responses, and show that a monocyte-related signature correlates with the neutralizing antibody response against the B.1.351 variant. Collectively, these data provide insights into the immune responses induced by mRNA vaccination and demonstrate its capacity to prime the innate immune system to mount a more potent response after booster immunization.


Assuntos
Imunidade Adaptativa , Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , Imunidade Inata , Linfócitos T/imunologia , Vacinologia , Adulto , Idoso , Anticorpos Neutralizantes/imunologia , Autoanticorpos/imunologia , Vacina BNT162 , Vacinas contra COVID-19/administração & dosagem , Feminino , Humanos , Imunização Secundária , Masculino , Pessoa de Meia-Idade , Análise de Célula Única , Glicoproteína da Espícula de Coronavírus/imunologia , Transcrição Gênica , Transcriptoma/genética , Adulto Jovem
8.
Nature ; 594(7862): 253-258, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33873199

RESUMO

The development of a portfolio of COVID-19 vaccines to vaccinate the global population remains an urgent public health imperative1. Here we demonstrate the capacity of a subunit vaccine, comprising the SARS-CoV-2 spike protein receptor-binding domain displayed on an I53-50 protein nanoparticle scaffold (hereafter designated RBD-NP), to stimulate robust and durable neutralizing-antibody responses and protection against SARS-CoV-2 in rhesus macaques. We evaluated five adjuvants including Essai O/W 1849101, a squalene-in-water emulsion; AS03, an α-tocopherol-containing oil-in-water emulsion; AS37, a Toll-like receptor 7 (TLR7) agonist adsorbed to alum; CpG1018-alum, a TLR9 agonist formulated in alum; and alum. RBD-NP immunization with AS03, CpG1018-alum, AS37 or alum induced substantial neutralizing-antibody and CD4 T cell responses, and conferred protection against SARS-CoV-2 infection in the pharynges, nares and bronchoalveolar lavage. The neutralizing-antibody response to live virus was maintained up to 180 days after vaccination with RBD-NP in AS03 (RBD-NP-AS03), and correlated with protection from infection. RBD-NP immunization cross-neutralized the B.1.1.7 SARS-CoV-2 variant efficiently but showed a reduced response against the B.1.351 variant. RBD-NP-AS03 produced a 4.5-fold reduction in neutralization of B.1.351 whereas the group immunized with RBD-NP-AS37 produced a 16-fold reduction in neutralization of B.1.351, suggesting differences in the breadth of the neutralizing-antibody response induced by these adjuvants. Furthermore, RBD-NP-AS03 was as immunogenic as a prefusion-stabilized spike immunogen (HexaPro) with AS03 adjuvant. These data highlight the efficacy of the adjuvanted RBD-NP vaccine in promoting protective immunity against SARS-CoV-2 and have led to phase I/II clinical trials of this vaccine (NCT04742738 and NCT04750343).


Assuntos
Adjuvantes Imunológicos , Anticorpos Neutralizantes/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Vacinas de Subunidades Antigênicas/imunologia , Compostos de Alúmen , Animais , Anticorpos Antivirais/imunologia , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , COVID-19/virologia , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Modelos Animais de Doenças , Imunidade Celular , Imunidade Humoral , Macaca mulatta/imunologia , Masculino , Oligodesoxirribonucleotídeos , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Esqualeno
9.
Nat Chem Biol ; 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38225471

RESUMO

A major challenge in creating universal influenza vaccines is to focus immune responses away from the immunodominant, variable head region of hemagglutinin (HA-head) and toward the evolutionarily conserved stem region (HA-stem). Here we introduce an approach to control antigen orientation via site-specific insertion of aspartate residues that facilitates antigen binding to alum. We demonstrate the generalizability of this approach with antigens from Ebola, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses and observe enhanced neutralizing antibody responses in all cases. We then reorient an H2 HA in an 'upside-down' configuration to increase the exposure and immunogenicity of HA-stem. The reoriented H2 HA (reoH2HA) on alum induced stem-directed antibodies that cross-react with both group 1 and group 2 influenza A subtypes. Electron microscopy polyclonal epitope mapping (EMPEM) revealed that reoH2HA (group 1) elicits cross-reactive antibodies targeting group 2 HA-stems. Our results highlight antigen reorientation as a generalizable approach for designing epitope-focused vaccines.

10.
Immunity ; 46(3): 446-456, 2017 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-28314593

RESUMO

Zika virus (ZIKV) has become a public health threat due to its global transmission and link to severe congenital disorders. The host immune responses to ZIKV infection have not been fully elucidated, and effective therapeutics are not currently available. Herein, we demonstrated that cholesterol-25-hydroxylase (CH25H) was induced in response to ZIKV infection and that its enzymatic product, 25-hydroxycholesterol (25HC), was a critical mediator of host protection against ZIKV. Synthetic 25HC addition inhibited ZIKV infection in vitro by blocking viral entry, and treatment with 25HC reduced viremia and conferred protection against ZIKV in mice and rhesus macaques. 25HC suppressed ZIKV infection and reduced tissue damage in human cortical organoids and the embryonic brain of the ZIKV-induced mouse microcephaly model. Our findings highlight the protective role of CH25H during ZIKV infection and the potential use of 25HC as a natural antiviral agent to combat ZIKV infection and prevent ZIKV-associated outcomes, such as microcephaly.


Assuntos
Antivirais/farmacologia , Hidroxicolesteróis/farmacologia , Microcefalia/virologia , Infecção por Zika virus/complicações , Animais , Encéfalo/efeitos dos fármacos , Modelos Animais de Doenças , Imunofluorescência , Humanos , Macaca mulatta , Camundongos , Microscopia Confocal , Internalização do Vírus/efeitos dos fármacos , Zika virus/efeitos dos fármacos , Zika virus/fisiologia
11.
Nat Mater ; 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38641696

RESUMO

Symmetry breaking in quantum materials is of great importance and can lead to non-reciprocal charge transport. Topological insulators provide a unique platform to study non-reciprocal charge transport due to their surface states, especially quantum Hall states under an external magnetic field. Here we report the observation of non-reciprocal charge transport mediated by quantum Hall states in devices composed of the intrinsic topological insulator Sn-Bi1.1Sb0.9Te2S, which is attributed to asymmetric scattering between quantum Hall states and Dirac surface states. A giant non-reciprocal coefficient of up to 2.26 × 105 A-1 is found. Our work not only reveals the properties of non-reciprocal charge transport of quantum Hall states in topological insulators but also paves the way for future electronic devices.

12.
PLoS Pathog ; 19(12): e1011859, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38060601

RESUMO

Microsporidia are a group of obligate intracellular parasites that infect almost all animals, causing serious human diseases and major economic losses to the farming industry. Nosema bombycis is a typical microsporidium that infects multiple lepidopteran insects via fecal-oral and transovarial transmission (TOT); however, the underlying TOT processes and mechanisms remain unknown. Here, we characterized the TOT process and identified key factors enabling N. bombycis to invade the ovariole and oocyte of silkworm Bombyx mori. We found that the parasites commenced with TOT at the early pupal stage when ovarioles penetrated the ovary wall and were exposed to the hemolymph. Subsequently, the parasites in hemolymph and hemolymph cells firstly infiltrated the ovariole sheath, from where they invaded the oocyte via two routes: (I) infecting follicular cells, thereby penetrating oocytes after proliferation, and (II) infecting nurse cells, thus entering oocytes following replication. In follicle and nurse cells, the parasites restructured and built large vacuoles to deliver themselves into the oocyte. In the whole process, the parasites were coated with B. mori vitellogenin (BmVg) on their surfaces. To investigate the BmVg effects on TOT, we suppressed its expression and found a dramatic decrease of pathogen load in both ovarioles and eggs, suggesting that BmVg plays a crucial role in the TOT. Thereby, we identified the BmVg domains and parasite spore wall proteins (SWPs) mediating the interaction, and demonstrated that the von Willebrand domain (VWD) interacted with SWP12, SWP26 and SWP30, and the unknown function domain (DUF1943) bound with the SWP30. When disrupting these interactions, we found significant reductions of the pathogen load in both ovarioles and eggs, suggesting that the interplays between BmVg and SWPs were vital for the TOT. In conclusion, our study has elucidated key aspects about the microsporidian TOT and revealed the key factors for understanding the molecular mechanisms underlying this transmission.


Assuntos
Bombyx , Nosema , Animais , Humanos , Vitelogeninas/metabolismo , Esporos Fúngicos/metabolismo , Nosema/metabolismo , Bombyx/metabolismo
13.
BMC Genomics ; 25(1): 321, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38556880

RESUMO

Congenital infection caused by vertical transmission of microsporidia N. bombycis can result in severe economic losses in the silkworm-rearing industry. Whole-transcriptome analyses have revealed non-coding RNAs and their regulatory networks in N. bombycis infected embryos and larvae. However, transcriptomic changes in the microsporidia proliferation and host responses in congenitally infected embryos and larvae remains unclear. Here, we simultaneously compared the transcriptomes of N. bombycis and its host B. mori embryos of 5-day and larvae of 1-, 5- and 10-day during congenital infection. For the transcriptome of N. bombycis, a comparison of parasite expression patterns between congenital-infected embryos and larva showed most genes related to parasite central carbon metabolism were down-regulated in larvae during infection, whereas the majority of genes involved in parasite proliferation and growth were up-regulated. Interestingly, a large number of distinct or shared differentially expressed genes (DEGs) were revealed by the Venn diagram and heat map, many of them were connected to infection related factors such as Ricin B lectin, spore wall protein, polar tube protein, and polysaccharide deacetylase. For the transcriptome of B. mori infected with N. bombycis, beyond numerous DEGs related to DNA replication and repair, mRNA surveillance pathway, RNA transport, protein biosynthesis, and proteolysis, with the progression of infection, a large number of DEGs related to immune and infection pathways, including phagocytosis, apoptosis, TNF, Toll-like receptor, NF-kappa B, Fc epsilon RI, and some diseases, were successively identified. In contrast, most genes associated with the insulin signaling pathway, 2-oxacarboxylic acid metabolism, amino acid biosynthesis, and lipid metabolisms were up-regulated in larvae compared to those in embryos. Furthermore, dozens of distinct and three shared DEGs that were involved in the epigenetic regulations, such as polycomb, histone-lysine-specific demethylases, and histone-lysine-N-methyltransferases, were identified via the Venn diagram and heat maps. Notably, many DEGs of host and parasite associated with lipid-related metabolisms were verified by RT-qPCR. Taken together, simultaneous transcriptomic analyses of both host and parasite genes lead to a better understanding of changes in the microsporidia proliferation and host responses in embryos and larvae in N. bombycis congenital infection.


Assuntos
Bombyx , Nosema , Animais , Transcriptoma , Larva/genética , Larva/metabolismo , Histonas/metabolismo , Lisina/metabolismo , Nosema/fisiologia , Perfilação da Expressão Gênica , Proliferação de Células , Lipídeos , Bombyx/genética
14.
Nat Mater ; 22(3): 380-390, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36717665

RESUMO

The ideal vaccine against viruses such as influenza and SARS-CoV-2 must provide a robust, durable and broad immune protection against multiple viral variants. However, antibody responses to current vaccines often lack robust cross-reactivity. Here we describe a polymeric Toll-like receptor 7 agonist nanoparticle (TLR7-NP) adjuvant, which enhances lymph node targeting, and leads to persistent activation of immune cells and broad immune responses. When mixed with alum-adsorbed antigens, this TLR7-NP adjuvant elicits cross-reactive antibodies for both dominant and subdominant epitopes and antigen-specific CD8+ T-cell responses in mice. This TLR7-NP-adjuvanted influenza subunit vaccine successfully protects mice against viral challenge of a different strain. This strategy also enhances the antibody response to a SARS-CoV-2 subunit vaccine against multiple viral variants that have emerged. Moreover, this TLR7-NP augments antigen-specific responses in human tonsil organoids. Overall, we describe a nanoparticle adjuvant to improve immune responses to viral antigens, with promising implications for developing broadly protective vaccines.


Assuntos
COVID-19 , Vacinas contra Influenza , Influenza Humana , Nanopartículas , Animais , Camundongos , Humanos , Influenza Humana/prevenção & controle , Receptor 7 Toll-Like/genética , SARS-CoV-2/genética , COVID-19/prevenção & controle , Adjuvantes Imunológicos/farmacologia , Imunidade , Vacinas de Subunidades Antigênicas
16.
Sensors (Basel) ; 24(1)2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38203165

RESUMO

When the workpiece surface exhibits strong reflectivity, it becomes challenging to obtain accurate key measurements using non-contact, visual measurement techniques due to poor image quality. In this paper, we propose a high-precision measurement method shaft diameter based on an enhanced quality stripe image. By capturing two stripe images with different exposure times, we leverage their different characteristics. The results extracted from the low-exposure image are used to perform grayscale correction on the high-exposure image, improving the distribution of stripe grayscale and resulting in more accurate extraction results for the center points. The incorporation of different measurement positions and angles further enhanced measurement precision and robustness. Additionally, ellipse fitting is employed to derive shaft diameter. This method was applied to the profiles of different cross-sections and angles within the same shaft segment. To reduce the shape error of the shaft measurement, the average of these measurements was taken as the estimate of the average diameter for the shaft segment. In the experiments, the average shaft diameters determined by averaging elliptical estimations were compared with shaft diameters obtained using a coordinate measuring machine (CMM) the maximum error and the minimum error were respectively 18 µm and 7 µm; the average error was 11 µm; and the root mean squared error of the multiple measurement results was 10.98 µm. The measurement accuracy achieved is six times higher than that obtained from the unprocessed stripe images.

17.
Nano Lett ; 23(3): 765-771, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36542799

RESUMO

Igniting interface magnetic ordering of magnetic topological insulators by building a van der Waals heterostructure can help to reveal novel quantum states and design functional devices. Here, we observe an interesting exchange bias effect, indicating successful interfacial magnetic coupling, in CrI3/MnBi2Te4 ferromagnetic insulator/antiferromagnetic topological insulator (FMI/AFM-TI) heterostructure devices. The devices originally exhibit a negative exchange bias field, which decays with increasing temperature and is unaffected by the back-gate voltage. When we change the device configuration to be half-covered by CrI3, the exchange bias becomes positive with a very large exchange bias field exceeding 300 mT. Such sensitive manipulation is explained by the competition between the FM and AFM coupling at the interface of CrI3 and MnBi2Te4, pointing to coverage-dependent interfacial magnetic interactions. Our work will facilitate the development of topological and antiferromagnetic devices.

18.
Molecules ; 29(11)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38893431

RESUMO

BACKGROUND: With the changes in lifestyle and diet structure, the incidence of obesity has increased year by year, and obesity is one of the inducements of many chronic metabolic diseases. Epigallocatechin gallate (EGCG), which is the most abundant component of tea polyphenols, has been used for many years to improve obesity and its complications. Though it has been reported that EGCG can improve obesity through many molecular mechanisms, EGCG may have many mechanisms yet to be explored. In this study, we explored other possible mechanisms through molecular docking and in vitro experiments. METHODS: AutoDock Vina was selected for conducting the molecular docking analysis to elucidate the interaction between EGCG and Notch1, while molecular dynamics simulations were employed to validate this interaction. Then, the new regulation mechanism of EGCG on obesity was verified with in vitro experiments, including a Western blot experiment, immunofluorescence experiment, oil red O staining, and other experiments in 3T3-L1 adipocytes. RESULTS: The molecular docking results showed that EGCG could bind to Notch1 protein through hydrogen bonding. In vitro cell experiments demonstrated that EGCG can significantly reduce the sizes of lipid droplets of 3T3-L1 adipocytes and promote UCP-1 expression by inhibiting the expression of Notch1 in 3T3-L1 adipocytes, thus promoting mitochondrial biogenesis. CONCLUSIONS: In this study, molecular docking and in vitro cell experiments were used to explore the possible mechanism of EGCG to improve obesity by inhibiting Notch1.


Assuntos
Adipogenia , Catequina , Simulação de Acoplamento Molecular , Receptor Notch1 , Animais , Camundongos , Células 3T3-L1 , Adipogenia/efeitos dos fármacos , Catequina/análogos & derivados , Catequina/farmacologia , Catequina/química , Regulação da Expressão Gênica/efeitos dos fármacos , Simulação de Dinâmica Molecular , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Receptor Notch1/metabolismo , Proteína Desacopladora 1/metabolismo
19.
BMC Genomics ; 24(1): 420, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37495972

RESUMO

BACKGROUND: The interaction networks between coding and non-coding RNAs (ncRNAs) including long non-coding RNA (lncRNA), covalently closed circular RNA (circRNA) and miRNA are significant to elucidate molecular processes of biological activities and interactions between host and pathogen. Congenital infection caused by vertical transmission of microsporidia N. bombycis can result in severe economic losses in the silkworm-feeding industry. However, little is known about ncRNAs that take place in the microsporidia congenital infection. Here we conducted whole-transcriptome RNA-Seq analyses to identify ncRNAs and regulatory networks for both N. bombycis and host including silkworm embryos and larvae during the microsporidia congenital infection. RESULTS: A total of 4,171 mRNAs, 403 lncRNA, 62 circRNAs, and 284 miRNAs encoded by N. bombycis were identified, among which some differentially expressed genes formed cross-talk and are involved in N. bombycis proliferation and infection. For instance, a lncRNA/circRNA competing endogenous RNA (ceRNA) network including 18 lncRNAs, one circRNA, and 20 miRNAs was constructed to describe 14 key parasites genes regulation, such as polar tube protein 3 (PTP3), ricin-B-lectin, spore wall protein 4 (SWP4), and heat shock protein 90 (HSP90). Regarding host silkworm upon N. bombycis congenital infection, a total of 14,889 mRNAs, 3,038 lncRNAs, 19,039 circRNAs, and 3,413 miRNAs were predicted based on silkworm genome with many differentially expressed coding and non-coding genes during distinct developmental stages. Different species of RNAs form interacting network to modulate silkworm biological processes, such as growth, metamorphosis and immune responses. Furthermore, a lncRNA/circRNA ceRNA network consisting of 140 lncRNAs, five circRNA, and seven miRNAs are constructed hypothetically to describe eight key host genes regulation, such as Toll-6, Serpin-6, inducible nitric oxide synthase (iNOS) and Caspase-8. Notably, cross-species analyses indicate that parasite and host miRNAs play a vital role in pathogen-host interaction in the microsporidia congenital infection. CONCLUSION: This is the first comprehensive pan-transcriptome study inclusive of both N. bombycis and its host silkworm with a specific focus on the microsporidia congenital infection, and show that ncRNA-mediated regulation plays a vital role in the microsporidia congenital infection, which provides a new insight into understanding the basic biology of microsporidia and pathogen-host interaction.


Assuntos
MicroRNAs , Microsporidiose , Nosema , RNA Longo não Codificante , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , RNA Circular/genética , Nosema/fisiologia , Interações Hospedeiro-Patógeno/genética , MicroRNAs/genética , RNA Mensageiro , Redes Reguladoras de Genes
20.
Cancer Control ; 30: 10732748231202466, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37728233

RESUMO

BACKGROUND: Tumor markers (TMs) are important for the prognosis of gastric cancer (GC). However, the prognostic importance of the tumor marker index (TMI) based on GC-specific TMs for advanced gastric cancer (AGC) still needs to be further explored. METHODS: We retrospectively examined patients who underwent radical gastric cancer surgery between February 2014 and June 2016 at the Department of Gastroenterological Surgery, Affiliated Cancer Hospital, Harbin Medical University. The patients were divided into training and validation groups. TMI was determined as the geometric mean of the standard cancer antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) levels. Patient overall survival was assessed using the Kaplan-Meier method. Independent prognosis-associated risk factors were identified using Cox hazard regression models. A nomogram model incorporating TMI and clinicopathological factors was developed, and its performance was evaluated using a decision curve analysis, concordance index, and calibration plots. RESULTS: In the TMI training cohort, the cutoff value was set at .439, categorizing patients into TMI-High and TMI-Low groups. The 5-year survival rate in the TMI-Low group significantly surpassed that in the TMI-High group (78.2% vs 58.1% and 49.7 vs 41.6, P < .001). TMI emerged as an independent prognostic factor. The nomogram accurately predicted patient prognosis by using TMI and clinicopathological characteristics. Validation of the TMI in the independent cohort yielded satisfactory results. CONCLUSION: The TMI constructed based on specific TMs associated with gastric cancer can offer a precise prognostic prediction for patients.


Assuntos
Biomarcadores Tumorais , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/patologia , Estadiamento de Neoplasias , Estudos Retrospectivos , Prognóstico
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