RESUMEN
Breakthrough infections by SARS-CoV-2 variants become the global challenge for pandemic control. Previously, we developed the protein subunit vaccine ZF2001 based on the dimeric receptor-binding domain (RBD) of prototype SARS-CoV-2. Here, we developed a chimeric RBD-dimer vaccine approach to adapt SARS-CoV-2 variants. A prototype-Beta chimeric RBD-dimer was first designed to adapt the resistant Beta variant. Compared with its homotypic forms, the chimeric vaccine elicited broader sera neutralization of variants and conferred better protection in mice. The protection of the chimeric vaccine was further verified in macaques. This approach was generalized to develop Delta-Omicron chimeric RBD-dimer to adapt the currently prevalent variants. Again, the chimeric vaccine elicited broader sera neutralization of SARS-CoV-2 variants and conferred better protection against challenge by either Delta or Omicron SARS-CoV-2 in mice. The chimeric approach is applicable for rapid updating of immunogens, and our data supported the use of variant-adapted multivalent vaccine against circulating and emerging variants.
Asunto(s)
COVID-19 , Vacunas , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19/prevención & control , Vacunas contra la COVID-19 , Humanos , Ratones , SARS-CoV-2/genéticaRESUMEN
Vaccines are urgently needed to control the ongoing pandemic COVID-19 and previously emerging MERS/SARS caused by coronavirus (CoV) infections. The CoV spike receptor-binding domain (RBD) is an attractive vaccine target but is undermined by limited immunogenicity. We describe a dimeric form of MERS-CoV RBD that overcomes this limitation. The RBD-dimer significantly increased neutralizing antibody (NAb) titers compared to conventional monomeric form and protected mice against MERS-CoV infection. Crystal structure showed RBD-dimer fully exposed dual receptor-binding motifs, the major target for NAbs. Structure-guided design further yielded a stable version of RBD-dimer as a tandem repeat single-chain (RBD-sc-dimer) which retained the vaccine potency. We generalized this strategy to design vaccines against COVID-19 and SARS, achieving 10- to 100-fold enhancement of NAb titers. RBD-sc-dimers in pilot scale production yielded high yields, supporting their scalability for further clinical development. The framework of immunogen design can be universally applied to other beta-CoV vaccines to counter emerging threats.
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Betacoronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Coronavirus del Síndrome Respiratorio de Oriente Medio/inmunología , Pandemias/prevención & control , Neumonía Viral/prevención & control , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/inmunología , Diseño Universal , Enzima Convertidora de Angiotensina 2 , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Betacoronavirus/química , COVID-19 , Vacunas contra la COVID-19 , Línea Celular Tumoral , Chlorocebus aethiops , Infecciones por Coronavirus/virología , Células HEK293 , Humanos , Ratones , Ratones Endogámicos BALB C , Coronavirus del Síndrome Respiratorio de Oriente Medio/química , Peptidil-Dipeptidasa A/genética , Peptidil-Dipeptidasa A/metabolismo , Neumonía Viral/virología , Unión Proteica , Dominios y Motivos de Interacción de Proteínas/inmunología , Receptores Virales/metabolismo , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/química , SARS-CoV-2 , Células Sf9 , Organismos Libres de Patógenos Específicos , Spodoptera , Transfección , Vacunación/métodos , Células Vero , Vacunas ViralesRESUMEN
Protective vaccines are crucial for preventing and controlling coronavirus disease 2019 (COVID-19). Updated vaccines are needed to confront the continuously evolving and circulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. These vaccines should be safe, effective, amenable to easily scalable production, and affordable. Previously, we developed receptor binding domain (RBD) dimer-based protein subunit vaccines (ZF2001 and updated vaccines) in mammalian cells. In this study, we explored a strategy for producing RBD-dimer immunogens in Pichia pastoris. We found that wild-type P. pastoris produced hyperglycosylated RBD-dimer protein containing four N-glycosylation sites in P. pastoris. Therefore, we engineered the wild type P. pastoris (GS strain) into GSΔOCH1pAO by deleting the OCH1 gene (encoding α-1,6-mannosyltransferase enzyme) to decrease glycosylation, as well as by overexpressing the HIS4 gene (encoding histidine dehydrogenase) to increase histidine synthesis for better growth. In addition, RBD-dimer protein was truncated to remove the R328/F329 cleavage sites in P. pastoris. Several homogeneous RBD-dimer proteins were produced in the GSΔOCH1pAO strain, demonstrating the feasibility of using the P. pastoris expression system. We further resolved the cryo-EM structure of prototype-Beta RBD-dimer complexed with the neutralizing antibody CB6 to reveal the completely exposed immune epitopes of the RBDs. In a murine model, we demonstrated that the yeast-produced RBD-dimer induces robust and protective antibody responses, which is suitable for boosting immunization. This study developed the yeast system for producing SARS-CoV-2 RBD-dimer immunogens, providing a promising platform and pipeline for the future continuous updating and production of SARS-CoV-2 vaccines.
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Vacunas contra la COVID-19 , COVID-19 , SARS-CoV-2 , SARS-CoV-2/inmunología , SARS-CoV-2/genética , Animales , Ratones , COVID-19/prevención & control , COVID-19/inmunología , Vacunas contra la COVID-19/inmunología , Glicosilación , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , Humanos , Anticuerpos Neutralizantes/inmunología , Ratones Endogámicos BALB C , Anticuerpos Antivirales/inmunología , Saccharomycetales/genética , Saccharomycetales/inmunología , Saccharomycetales/metabolismo , Femenino , Pichia/genética , Pichia/metabolismoRESUMEN
SARS-CoV-2 variants with severe immune evasion are a major challenge for COVID-19 prevention, especially the circulating Omicron XBB/BQ.1.1/BF.7 strains. Thus, the next-generation of broad-spectrum vaccines are urgently needed. Previously, we developed a COVID-19 protein subunit vaccine, ZF2001, based on the RBD-homodimer as the immunogen. To adapt SARS-CoV-2 variants, we developed chimeric RBD-heterodimers to induce broad immune responses. In this study, we further explored the concept of tandem RBD homotrimer and heterotrimer. Prototype SARS-CoV-2 RBD-homotrimer, prototype-Delta-BA.1 (PDO) RBD-heterotrimer and Delta-BA.2-BA.5 (DBA2BA5) RBD-heterotrimer were designed. Biochemical and cryo-EM structural characterization demonstrated total epitope exposure of the RBD-trimers. In mouse experiments, PDO and DBA2BA5 elicited broad SARS-CoV-2 neutralization. Potent protection against SARS-CoV-2 variants was observed in challenge assays and was correlated with neutralizing antibody titer. This study validated the design strategy of tandem RBD-heterotrimers as multivalent immunogens and presented a promising vaccine candidate, DBA2BA5, eliciting broad-spectrum immune responses, including against the circulating XBB/BF.7/BQ.1.1.
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COVID-19 , Vacunas , Animales , Ratones , SARS-CoV-2/genética , COVID-19/prevención & control , Anticuerpos Neutralizantes , Anticuerpos AntiviralesRESUMEN
Arnebiae Radix, commonly known as "Zicao," can be easily confused with other compounding species, posing challenges for its clinical use. Here, we developed a comprehensive strategy to systematically characterize the diverse components across Arnebiae Radix and its three confusing species. First, an offline two-dimensional liquid chromatography (2D-LC) system integrating hydrophilic interaction chromatography (HILIC) and reverse phase (RP) separations was established, enabling effective separation and detection of more trace constituents. Second, a polygonal mass defect filtering (MDF) workflow was implemented to screen target ions and generate a precursor ion list (PIL) to guide multistage mass (MSn) data acquisition. Third, a three-step characterization strategy utilizing diagnostic ions and neutral losses was developed for rapid determination of molecular formulas, structure classes, and compound identification. This approach enabled systematic characterization of Arnebiae Radix and its three confusing species, with 437 components characterized including 112 shikonins, 22 shikonfurans, 144 phenolic acids, 131 glycosides, 18 flavonoids, and 10 other compounds. Additionally, 361, 230, 340, and 328 components were identified from RZC, YZC, DZC, and ZZC, respectively, with 142 common components and 30 characteristic components that may serve as potential markers for distinguishing the four species. In summary, this is the first comprehensive characterization and comparison of the phytochemical profiles of Arnebiae Radix and its three confusing species, advancing our understanding of this herbal medicine for quality control.
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Medicamentos Herbarios Chinos , Cromatografía Líquida de Alta Presión/métodos , Medicamentos Herbarios Chinos/química , Cromatografía Líquida con Espectrometría de Masas , Flavonoides/análisis , IonesRESUMEN
Eleven new steroidal alkaloids, along with nine known related compounds, were isolated from the bulbs of Fritillaria sinica. Seven pairs of diastereomers were identified, including six and four 20-deoxy cevanine-type steroidal alkaloid diastereomers with molecular weights of 413 and 415, respectively. Structures were elucidated based on spectroscopic data analysis, chemical derivatization, and single-crystal X-ray diffraction analysis. Compounds 5, 9, 11, 12, 16, and 20 exhibited significant in vitro cytotoxic activity against non-small-cell lung cancer with CC50 values from 6.8 ± 3.9 to 12 ± 5 µM.
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Alcaloides , Antineoplásicos , Carcinoma de Pulmón de Células no Pequeñas , Fritillaria , Neoplasias Pulmonares , Humanos , Fritillaria/química , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Estructura Molecular , Neoplasias Pulmonares/tratamiento farmacológico , Alcaloides/química , Esteroides/químicaRESUMEN
The coronavirus disease 2019 (COVID-19) pandemic posed great impacts on public health. To fight against the pandemic, robust immune responses induced by vaccination are indispensable. Previously, we developed a subunit vaccine adjuvanted by aluminum hydroxide, ZF2001, based on the dimeric tandem-repeat RBD immunogen, which has been approved for clinical use. This dimeric RBD design was also explored as an mRNA vaccine. Both showed potent immunogenicity. In this study, a DNA vaccine candidate encoding RBD-dimer was designed. The humoral and cellular immune responses induced by homologous and heterologous prime-boost approaches with DNA-RBD-dimer and ZF2001 were assessed in mice. Protection efficacy was studied by the SARS-CoV-2 challenge. We found that the DNA-RBD-dimer vaccine was robustly immunogenic. Priming with DNA-RBD-dimer followed by ZF2001 boosting induced higher levels of neutralizing antibodies than homologous vaccination with either DNA-RBD-dimer or ZF2001, elicited polyfunctional cellular immunity with a TH 1-biased polarization, and efficiently protected mice against SARS-CoV-2 infection in the lung. This study demonstrated the robust and protective immune responses induced by the DNA-RBD-dimer candidate and provided a heterologous prime-boost approach with DNA-RBD-dimer and ZF2001.
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COVID-19 , Vacunas de ADN , Vacunas Virales , Humanos , Animales , Ratones , Vacunas contra la COVID-19 , COVID-19/prevención & control , SARS-CoV-2 , Vacunación , Anticuerpos Neutralizantes , Inmunidad Celular , Anticuerpos AntiviralesRESUMEN
Jujube fruit was well-loved and praised by the broad masses due to its delicious taste, abundant nutritional value, and medicinal properties. Few studies reported the quality evaluation and gut microbiota regulation effect of polysaccharides of jujube fruits from different producing areas. In the present study, multi-level fingerprint profiling, including polysaccharides, oligosaccharides, and monosaccharides, was established for the quality evaluation of polysaccharides from jujube fruits. For polysaccharides, the total content in jujube fruits ranged from 1.31% to 2.22%, and the molecular weight distribution (MWD) ranged from 1.14 × 105 to 1.73 × 106 Da. The MWD fingerprint profiling of polysaccharides from eight producing areas was similar, but the profile of infrared spectroscopy (IR) showed differentiation. The characteristic signals were screened and used to establish a discrimination model for the identification of jujube fruits from different areas, and the accuracy of identification reached 100.00%. For oligosaccharides, the main components were galacturonic acid polymers (DP, 2-4), and the profile of oligosaccharides exhibited high similarity. The monosaccharides, GalA, Glc, and Ara, were the primary monosaccharides. Although the fingerprint of monosaccharides was semblable, the composing proportion of monosaccharides revealed significant differences. In addition, the polysaccharides of jujube fruits could regulate the gut microbiota composition and possess potential therapeutic effects on dysentery and nervous system diseases.
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Microbioma Gastrointestinal , Ziziphus , Frutas/química , Ziziphus/química , Polisacáridos/química , MonosacáridosRESUMEN
Comprehensive analysis and identification of chemical components are of great significance for evaluating the efficacy and safety of herbal medicines, as well as for drug exploitation and development. Here we developed a "force iteration molecular designing" strategy, by combing a database-based in-house software for a precursor ion list (PIL) and PIL-triggered collision-induced dissociation-MS2 and high-energy C-trap dissociation-MS2 (PIL-CID/MS2-HCD/MS2) on an LTQ-Orbitrap mass spectrometer, aiming for the systematic characterization and discovery of new protostane triterpenoids (PTs) from Alisma Rhizoma (AR). AR was a well-known herbal remedy widely used for diarrhea, but its systematic characterization and comparison between two botanical origins have not been reported. Firstly, in-house software was developed based on force iteration, to generate a PIL that contains 483 accurate precursor ions. Secondly, to facilitate the acquisition of rich fragments and diagnostic ions sufficient for the structural elucidation of different types of PTs, a hybrid data acquisition method, namely PIL-CID/MS2-HCD/MS2, was generated. Thirdly, a total of 473 PTs were rapidly characterized from two botanical origins of AR according to an established four-step interpretation method, and the common constituents were 277 with ratio 70% (277/395) and 78% (277/355) in the rhizome of Alisma plantago-aquatica and A. orientale, respectively. Finally, two new PTs were isolated and unambiguously identified by NMR verifying the feasibility of this combined data acquisition strategy. This integrated strategy could improve the efficiency in the detection of new compounds in a single run and is practical to comprehensively characterize the complex components in herbal medicines.
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Alisma/metabolismo , Técnicas de Química Analítica/métodos , Cromatografía Líquida de Alta Presión/métodos , Espectrometría de Masas/métodos , Triterpenos/análisis , Medicamentos Herbarios Chinos , Iones , Espectroscopía de Resonancia Magnética , Plantas Medicinales/química , Reproducibilidad de los Resultados , Programas InformáticosRESUMEN
Developing high-quality standard is useful for promoting the quality of traditional Chinese medicine injections, which could be evaluated by establishing the comprehensive quality control method. A method for simultaneous determination of salvianolic acid B, rosmarinic acid and lithospermic acid in Salvianolate for Injection was developed for quantitative analysis of multi-components with single-marker(QAMS). ZORBAX Eclipse Plus C_(18) chromatographic column was adopted, with 0.1% phosphoric acid and acetonitrile as mobile phase. The flow rate was set at 1 mL·min~(-1). The column temperature was set at 20 â, and the detection wavelength was 286 nm. Salvianolic acid B was used as internal reference. The relative correction factors of rosmarinic acid and lithospermic acid(f_(s/i)) were 0.58 and 0.94, respectively. About 85% of substances in Salvianolate for Injection were quantified by the established QAMS method. The analysis of different batches of intermediates and preparations during four years showed that the contents of salvianolic acid B were 77.1%-81.5% in intermediates and 70.5%-80.1% in preparations; The total content of rosmarinic acid and lithospermic acid was about 6%. The ratio of rosmarinic acid to lithospermic acid was(3.4â¶1-10â¶1) and(2.5â¶1-5â¶1), respectively, which showed that the ratio was more stable in preparation. The QAMS method established is feasible for comprehensive quality control of multiple components of in Salvianolate for Injection.
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Medicamentos Herbarios Chinos , Extractos Vegetales/análisis , Cromatografía Líquida de Alta Presión , Medicina Tradicional ChinaRESUMEN
A commercial high-resolution MS database "TCM-PCDL" was innovatively introduced to automatically identify multi-components in 73 edible flowers rapidly and accurately by liquid chromatography-high resolution mass spectrometry, which can be time-consuming and labor-intensive in traditional manual method. The database encompasses over 2565 natural products with various energy levels. Unknown compounds can be identified through direct matching and scoring MS2 spectra with database. A total of 870 compounds were identified from 73 flowers, with polyphenols constituting up to 75%. Focusing on polyphenols, a high performance liquid chromatography (HPLC) method was developed to generate fingerprints from 510 batches, establishing an "HPLC database" that enabled accurate authentication using similarity scores and rankings. This method demonstrated an accuracy rate of 100% when applied to 30 unknown samples. For flowers prone to confusion, additional statistical analysis methods could be employed as aids in authentication. This study provides valuable insights for large-scale sample chemical profiling and authentication.
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Extractos Vegetales , Espectrometría de Masas en Tándem , Espectrometría de Masas en Tándem/métodos , Cromatografía Líquida de Alta Presión/métodos , Extractos Vegetales/química , Polifenoles , FloresRESUMEN
BACKGROUND: Fritillaria Bulbus (FB), a precious medicinal herb renowned for its heat-clearing, lung-moistening, cough-relieving and phlegm-eliminating effects. In pursuit of profits, unscrupulous merchants have engaged in the substitution or adulteration of valuable varieties with cheaper alternatives. It is, therefore, urgent to develop effective technical approaches to identify FBs from adulterants. METHODS: This paper employed infrared spectroscopy (IR), thin layer chromatography-image analysis (TLC-IA), and untargeted metabolomics techniques to discriminate ten species of FBs. RESULTS: Five species of FBs were successfully differentiated using mid-infrared spectroscopy. Furthermore, the power of TLC-IA technology allowed the differentiation of five species of FBs and two origins of FCBs (Fritillariae Cirrhosae Bulbus). Remarkably, through the application of untargeted metabolomics technique, the precise discrimination of five species of FBs, as well as three origins of FCBs were accomplished. Moreover, a comprehensive identification of 101 markers that reliably distinguished diverse FBs was achieved through the employment of untargeted metabolomics technique. CONCLUSION: The investigation presented powerful means of detection for assuring the quality control of Fritillaria herbs.
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Fritillaria , Plantas Medicinales , Fritillaria/química , Cromatografía en Capa Delgada , Plantas Medicinales/química , Control de Calidad , Análisis Espectral , MetabolómicaRESUMEN
Intranasal vaccines, eliciting mucosal immune responses, can prevent early invasion, replication, and transmission of pathogens in the respiratory tract. However, the effective delivery of antigens through the nasal barrier and boosting of a robust systematic and mucosal immune remain challenges in intranasal vaccine development. Here, we describe an intranasally administered self-healing hydrogel vaccine with a reversible strain-dependent sol-gel transition by precisely modulating the self-assembly processes between the natural drug rhein and aluminum ions. The highly bioadhesive hydrogel vaccine enhances antigen stability and prolongs residence time in the nasal cavity and lungs by confining the antigen to the surface of the nasal mucosa, acting as a "mucosal mask". The hydrogel also stimulates superior immunoenhancing properties, including antigen internalization, cross-presentation, and dendritic cell maturation. Furthermore, the formulation recruits immunocytes to the nasal mucosa and nasal-associated lymphoid tissue (NALT) while enhancing antigen-specific humoral, cellular, and mucosal immune responses. Our findings present a promising strategy for preparing intranasal vaccines for infectious diseases or cancer.
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Administración Intranasal , Hidrogeles , Inmunidad Mucosa , Mucosa Nasal , Animales , Hidrogeles/química , Ratones , Inmunidad Mucosa/efectos de los fármacos , Mucosa Nasal/inmunología , Ratones Endogámicos BALB C , Femenino , Humanos , Ratones Endogámicos C57BLRESUMEN
BACKGROUND: The recently circulating Omicron variants BA.2.86 and JN.1 were identified with more than 30 amino acid changes on the spike protein compared to BA.2 or XBB.1.5. This study aimed to comprehensively assess the immune escape potential of BA.2.86, JN.1, EG.5, and EG.5.1. METHODS: We collected human and murine sera to evaluate serological neutralization activities. The participants received three doses of coronavirus disease 2019 (COVID-19) vaccines or a booster dose of the ZF2022-A vaccine (Delta-BA.5 receptor-binding domain [RBD]-heterodimer immunogen) or experienced a breakthrough infection (BTI). The ZF2202-A vaccine is under clinical trial study (ClinicalTrials.gov: NCT05850507). BALB/c mice were vaccinated with a panel of severe acute respiratory syndrome coronavirus 2 RBD-dimer proteins. The antibody evasion properties of these variants were analyzed with 41 representative human monoclonal antibodies targeting the eight RBD epitopes. FINDINGS: We found that BA.2.86 had less neutralization evasion than EG.5 and EG.5.1 in humans. The ZF2202-A booster induced significantly higher neutralizing titers than BTI. Furthermore, BA.2.86 and JN.1 exhibited stronger antibody evasion than EG.5 and EG.5.1 on RBD-4 and RBD-5 epitopes. Compared to BA.2.86, JN.1 further lost the ability to bind to several RBD-1 monoclonal antibodies and displayed further immune escape. CONCLUSIONS: Our data showed that the currently dominating sub-variant, JN.1, showed increased immune evasion compared to BA.2.86 and EG.5.1, which is highly concerning. This study provides a timely risk assessment of the interested sub-variants and the basis for updating COVID-19 vaccines. FUNDING: This work was funded by the National Key R&D Program of China, the National Natural Science Foundation of China, the Beijing Life Science Academy, the Bill & Melinda Gates Foundation, and the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation (CPSF).
Asunto(s)
Anticuerpos Monoclonales , Anticuerpos Neutralizantes , Vacunas contra la COVID-19 , COVID-19 , Ratones Endogámicos BALB C , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Vacunas de Subunidad , Humanos , Animales , Anticuerpos Monoclonales/inmunología , SARS-CoV-2/inmunología , Ratones , Vacunas contra la COVID-19/inmunología , Vacunas contra la COVID-19/administración & dosificación , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , COVID-19/prevención & control , COVID-19/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/química , Vacunas de Subunidad/inmunología , Vacunas de Subunidad/administración & dosificación , Femenino , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Betacoronavirus/inmunología , Masculino , Sueros Inmunes/inmunología , Adulto , Evasión Inmune , Pruebas de Neutralización , Epítopos/inmunologíaRESUMEN
Comprehensive and rapid analysis of secondary metabolites like saponins remains challenging. This study aimed to establish a semi-automated workflow for filtration, identification, and characterization of saikosaponins in six Bupleurum species. Radix Bupleuri, a high-sales herbal medicine, is often adulterated, restricting its quality control and applications. Two authentic Radix Bupleuri species and four major adulterants were analyzed through UHPLC-LTQ-Orbitrap-MS for targeted saikosaponin analysis. To reveal trace saikosaponins and obtain quality fragment data, a MATLAB-based process automatically enumerating "sugar chain + aglycone + side chain" combinations and deduplicating generated a predicted saikosaponin database covering all possible saikosaponins as a precursor ion list for comprehensive targeted acquisition. To focus on informative ions and reduce MS analysis workload, we utilized MATLAB to automatically filtrate the false positive ions by MS1 and MS2 spectrometry. The newly established MATLAB-assisted data acquisition approach exhibited 50 % improvement in characterization of targeted saikosaponins. Furthermore, positive and negative ionization workflows were designed for accurate saikosaponins characterization based on fragmentation rules. In total, 707 saikosaponins were characterized, including over 500 potential new compounds and previously unreported C29 aglycones. We identified 25 saikosaponins present in both authentic species but absent in adulterants as potential markers. This unprecedented comprehensive multi-origin species differentiation demonstrates the promise of MATLAB-assisted acquisition and processing to advance saponin identification and standardize the Radix Bupleuri market.
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Bupleurum , Medicamentos Herbarios Chinos , Ácido Oleanólico , Saponinas , Medicamentos Herbarios Chinos/química , Bupleurum/química , Extractos Vegetales , Saponinas/análisis , Ácido Oleanólico/análisis , Cromatografía Liquida , Espectrometría de Masas , Iones , Cromatografía Líquida de Alta Presión/métodosRESUMEN
The SARS-CoV-2 Omicron variants of concern (VOCs) showed severe resistance to the early-approved COVID-19 vaccines-induced immune responses. The breakthrough infections by the Omicron VOCs are currently the major challenge for pandemic control. Therefore, booster vaccination is crucial to enhance immune responses and protective efficacy. Previously, we developed a protein subunit COVID-19 vaccine ZF2001, based on the immunogen of receptor-binding domain (RBD) homodimer, which was approved in China and other countries. To adapt SARS-CoV-2 variants, we further developed chimeric Delta-Omicron BA.1 RBD-dimer immunogen which induced broad immune responses against SARS-CoV-2 variants. In this study, we tested the boosting effect of this chimeric RBD-dimer vaccine in mice after priming with two doses of inactivated vaccines, compared with a booster of inactivated vaccine or ZF2001. The results demonstrated that boosting with bivalent Delta-Omicron BA.1 vaccine greatly promoted the neutralizing activity of the sera to all tested SARS-CoV-2 variants. Therefore, the Delta-Omicron chimeric RBD-dimer vaccine is a feasible booster for those with prior vaccination of COVID-19 inactivated vaccines.
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COVID-19 , Proteínas Portadoras , Animales , Humanos , Ratones , Vacunas contra la COVID-19 , SARS-CoV-2 , Subunidades de Proteína , COVID-19/prevención & control , Anticuerpos Neutralizantes , Anticuerpos AntiviralesRESUMEN
Current attempts in vaccine delivery systems concentrate on replicating the natural dissemination of live pathogens, but neglect that pathogens evolve to evade the immune system rather than to provoke it. In the case of enveloped RNA viruses, it is the natural dissemination of nucleocapsid protein (NP, core antigen) and surface antigen that delays NP exposure to immune surveillance. Here, we report a multi-layered aluminum hydroxide-stabilized emulsion (MASE) to dictate the delivery sequence of the antigens. In this manner, the receptor-binding domain (RBD, surface antigen) of the spike protein was trapped inside the nanocavity, while NP was absorbed on the outside of the droplets, enabling the burst release of NP before RBD. Compared with the natural packaging strategy, the inside-out strategy induced potent type I interferon-mediated innate immune responses and triggered an immune-potentiated environment in advance, which subsequently boosted CD40+ DC activations and the engagement of the lymph nodes. In both H1N1 influenza and SARS-CoV-2 vaccines, rMASE significantly increased antigen-specific antibody secretion, memory T cell engagement, and Th1-biased immune response, which diminished viral loads after lethal challenge. By simply reversing the delivery sequence of the surface antigen and core antigen, the inside-out strategy may offer major implications for enhanced vaccinations against the enveloped RNA virus.
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COVID-19 , Subtipo H1N1 del Virus de la Influenza A , Humanos , Antígenos Virales , Vacunas contra la COVID-19 , SARS-CoV-2 , Vacunación , Antígenos de Superficie , AnticuerposRESUMEN
Protein subunit vaccines have been widely used to combat infectious diseases, including the current COVID-19 pandemic. Adjuvants play the key role in shaping the quality and magnitude of the immune response to protein and inactivated vaccines. We previously developed a protein subunit COVID-19 vaccine, termed ZF2001, based on an aluminium hydroxide-adjuvanted tandem-repeat dimeric receptor-binding domain (RBD) of the viral spike (S) protein. Here, we described the use of a squalene-based oil-in-water adjuvant, Sepivac SWE™ (abbreviated to SWE), to further improve the immunogenicity of this RBD-dimer-based subunit vaccines. Compared with ZF2001, SWE adjuvant enhanced the antibody and CD4+ T-cell responses in mice with at least 10 fold of dose sparing compared with ZF2001 adjuvanted with aluminium hydroxide. SWE-adjuvanted vaccine protected mice against SARS-CoV-2 challenge. To ensure adequate protection against the currently circulating Omicron variant, we evaluated this adjuvant in combination with Delta-Omicron chimeric RBD-dimer. SWE significantly increased antibody responses compared with aluminium hydroxide adjuvant and afforded greater neutralization breadth. These data highlight the advantage of emulsion-based adjuvants to elevate the protective immune response of protein subunit COVID-19 vaccines.
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Vacunas contra la COVID-19 , Adyuvantes de Vacunas , Multimerización de Proteína , Anticuerpos Antivirales/inmunología , SARS-CoV-2/genética , Mutación , Ratones Endogámicos BALB C , Humanos , Animales , Ratones , Sitios de Unión , Línea CelularRESUMEN
Few studies reported the quality evaluation and gut microbiota regulation effect of polysaccharides from Fritillaria species. In this study, polysaccharides extracted from ten Fritillaria species were compared and distinguished through multi-levels evaluation strategy and data fusion. Furthermore, the gut microbiota regulation effect of polysaccharides among different species was analyzed and evaluated. The fingerprint profiling of IR, molecular weight distribution of polysaccharides, chromatogram of partially hydrolyzed polysaccharides (oligosaccharides) and completely hydrolyzed polysaccharides (monosaccharides) were similar, and no exclusive signals were observed. However, the signal strength of functional group, oligosaccharides abundance and monosaccharides proportion showed obvious differences in inter- and intra-species. Glucan may be the main component of polysaccharides in Fritillaria species, CIRR derived from CIR, PRZ, DEL, TAI, UNI possessed higher total polysaccharides content, polymerization degree, oligosaccharides abundance (DP 2-4), and glucose content than the others. Meanwhile, data fusion model was established for identification of affinis and multi-original species, the accuracy of which proved to be 100 %. In addition, Fritillaria polysaccharides could increase the bacterial community richness and diversity, regulate the gut microbiota composition and possessed potential therapeutic effects on gastrointestinal diseases and nervous system diseases.