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1.
Clin Lab ; 67(2)2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33616334

RESUMO

BACKGROUND: COVID-19 has recently been declared an epidemic by the WHO, and there is an urgent need for affected countries and laboratories to assess and treat people at risk of COVID-19. A heat procedure has been suggested for specimen inactivation. This study was designed to evaluate the effect of serum heating on biochemical indexes, and providing a basis for accurate detection results of the COVID-19 patients. METHODS: We collected 29 normal cases of two tubes of 5 mL whole blood. One tube was analyzed directly, and the other was analyzed after heating at 56°C 30 minutes. RESULTS: A total of 34 serum biochemical index quantitative results were obtained, 28/34 indexes were not significantly affected by the heat inactivation and remained clinically interpretable. As the thermal inactivation for these indexes showed good correlation, ALB (p = 0.04, Pearson R = 0.91, 2.6% mean increase), CysC (p = 0.03, Pearson R = 0.98, 9.9% mean increase), CO2CP (p < 0.001, Pearson R = 0.96, 13% mean decrease), they were still inter-pretable. Four biochemical indexes ALP, CK, CK-MB, and insulin were inactivated and showed significant statistical differences (p < 0.001). CONCLUSIONS: Our study showed CK, CK-MB, ALP, and insulin were sensitive to heat and will be inhibited or degrade after heating, indicating that the rapid decrease of this indexes in the COVID-19 patients may be caused by sample heat inactivation. For safety and diagnostic accuracy, we recommend the use of a point-of-care device for blood gases, electrolytes, troponin, and liver and renal function tests within a ISL 2 or above biosafety cabinet with level 3 or above biosafety laboratory practice.

2.
Int J Med Sci ; 18(1): 176-186, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33390786

RESUMO

Objective: The aim of this study was to observe the liver function recovery of COVID-19 patients after discharge. Patients and Methods: A total of 253 discharged COVID-19 patients in Shenzhen city, China were selected. The clinical characteristics of these patients were assessed. A 2-month follow-up and laboratory hematology test were performed to examine the status of patients' liver function. Results: Patients combined with liver diseases, especially fatty liver, are more likely to progress to severe condition (P<0.05). Patients in severe condition and those with liver diseases have higher rates of liver injuries during hospitalization, characterized by a significant increase in alanine aminotransferase (ALT) and aspartate aminotransferase (AST, P<0.01). The ALT, AST/ALT, gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), total protein (TP), albumin (ALB), and A/G levels showed significant differences in comparison with the control group (P<0.05, and P<0.001); and the outlier ratio of A/G, ALT, GGT and ALP of patients remained abnormal higher within 14 days after discharge (P<0.001). Liver injuries of COVID-19 patients may be related to the epidemiological characteristics, clinical indexes, basic diseases, symptoms, drug treatment during hospitalization and the complications. Indicators of liver function were correlated with cardiac function, renal function, thyroid function, lipid metabolism, glucose metabolism, immune index, leukocyte, erythrocyte, hemoglobin and platelet related indexes. The outlier ratio of TP, ALB and GLB remained extremely low throughout the follow-up period; the outlier ratio of ALT, AST and GGT decreased below 10% from a high level at 40 days after discharged. However, the outlier ratio of A/G, AST/ALT and ALP remained high during the follow-up period. Conclusions: Abnormal liver function might indicate worse recovery of COVID-19 patients. Changes in liver function should be emphasized during long-term follow-up of COVID-19 patients after hospital discharge; the necessity of employing appropriate interventions for liver function repair should be emphasized.


Assuntos
/complicações , Insuficiência Hepática/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Seguimentos , Humanos , Lactente , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica , Adulto Jovem
3.
Int J Med Sci ; 18(2): 347-355, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33390803

RESUMO

Objectives: Research on recovering COVID-19 patients could be helpful for containing the pandemic and developing vaccines, but we still do not know much about the clinical features, recovery process, and antibody reactions during the recovery period. Methods: We retrospectively analysed the epidemiological information, discharge summaries, and laboratory results of 324 patients. Results: In all, 15 (8.62%) patients experienced chest distress/breath shortness, where 8 of the 15 were severely ill. This means severely ill patients need an extended amount of time to recover after discharge; next, 20 (11.49%) patients experienced anxiety and 21 (12.07%) had headache/insomnia and a small fraction of them complained of anosmia/ageusia, indicating that these patients need treatment for mental and psychological health issues. Regarding the re-positive patients, their CT and laboratory test results showed no obvious evidence of illness progress or infectivity but a high anti-SARS-CoV-2 antibody expression. Conclusion: Recovered COVID-19 patients need psychological and physiological care and treatment, re-positivity can occur in any person, but juveniles, females, and patients with mild/moderate existing symptoms have higher rates of re-positivity, While there is no evidence that turning re-positive has an impact on their infectivity, but it still alerted us that we need differentiate them in the following managements.


Assuntos
/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Ageusia , /reabilitação , Criança , Pré-Escolar , China/epidemiologia , Feminino , Seguimentos , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Adulto Jovem
4.
J Nutr Biochem ; 87: 108493, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32920091

RESUMO

Dietary interventions such as fasting have been proved to be effective in the prevention of metabolic and autoimmune diseases as well as aging-related conditions. The complicated interaction between nutrition and immunity has drawn wide attention in recent years. In this study, we investigated the therapeutic effect of intermittent caloric restriction on autoimmune encephalomyelitis (EAE), a model of multiple sclerosis, in mice. EAE was induced by immunization of C57BL/6 mice with myelin oligodendrocyte glycoprotein 35-55 peptide. After the EAE symptoms became obvious at the 4th week post-immunization, the mice were administered with a modified fasting-mimicking diet (FMD) at 1/3 cal of control for 3 days, followed by ad libitum with normal chow for 4 days. A total of two cycles of FMD was applied. Compared with the mice without receiving caloric restriction, the mice using FMD had significant decreases in EAE severity, immune cell infiltration in spinal cord and CNS demyelination. FMD administration also reversed EAE-mediated CNS accumulation of total CD4+ T cells and in particular, IFN-γ-producing CD4+ T cells. Moreover, FMD application elevated the cell proliferation rate in CNS and enhanced expression of brain-derived neurotrophic factor (BDNF) and remyelination markers. In conclusion, our results indicate that intermittent caloric restriction using the modified FMD was effective in the treatment of EAE through ameliorating inflammatory response and promoting recovery of the damaged tissue.

5.
Magn Reson Med ; 85(3): 1669-1680, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32970911

RESUMO

PURPOSE: This paper studies the RF-induced heating for modular external fixation devices applied on the leg regions of the human bodies. Through numerical investigations of RF-induced heating related to different patient orientations, landmark positions, and device positions under 1.5T and 3T MRI systems, simple and practical methods to reduce RF-induced heating are recommended. METHODS: Numerical simulations using a full-wave electromagnetic solver based on the finite-difference time-domain method were performed to characterize the effects of patient orientations (head-first/feet-first), landmark positions (the scanning area of the patient), and device positions (device on left or right leg) on the RF-induced heating of the external fixation devices. The G32 coil design and three anatomical human models (Duke model, Ella model, and Fats model) were adopted to model the MRI RF coil and the patients. RESULTS: The relative positions of the patient, device, and coil can significantly affect the RF-induced heating. With other conditions remaining the same, changing the device position or patient orientation can lead to a peak 1-g averaged spatial absorption ratio variation of a factor around four. By changing the landmark position and the patient orientation, the RF-induced heating can be reduced from 1323.6 W/kg to 217.5 W/kg for the specific scanning situations studied. CONCLUSION: Patient orientations, landmark positions, and device positions influence the RF-induced heating of modular external fixation devices at 1.5 T and 3 T. These features can be used to reduce the RF-induced heating during MRI simply and practically.

6.
ISA Trans ; 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33160617

RESUMO

In this paper, we tackled the robust quantized proximity control problem for spacecraft with uncertain system parameters, external disturbances and safety constraint. As a stepping stone, a nonconvex forbidden zone composed of a cylinder and an ellipsoid is established around the target spacecraft. Then, a novel repulsive potential function is employed to encode the collision-avoidance requirement. Furthermore, an adaptive safety controller is proposed for spacecraft rendezvous and docking by combining the artificial potential function with sliding mode methodology. Within the Lyapunov framework, rigorous stability analysis indicates that the presented controller guarantees the ultimate boundedness of all system signals, whilst providing a real-time safety trajectory for the chaser spacecraft. Finally, simulation results validates the theoretical analysis.

7.
Sci Rep ; 10(1): 11887, 2020 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-32681141

RESUMO

Recently, the recurrence of positive SARS-CoV-2 viral RNA in recovered COVID-19 patients is receiving more attention. Herein we report a cohort study on the follow-up of 182 recovered patients under medical isolation observation. Twenty (10.99%) patients out of the 182 were detected to be SARS-CoV-2 RNA positive (re-positives), although none showed any clinical symptomatic recurrence, indicating that COVID-19 responds well to treatment. Patients aged under 18 years had higher re-positive rates than average, and none of the severely ill patients re-tested positive. There were no significant differences in sex between re-positives and non-re-positives. Notably, most of the re-positives turned negative in the following tests, and all of them carried antibodies against SARS-CoV-2. This indicates that they might not be infectious, although it is still important to perform regular SARS-CoV-2 RNA testing and follow-up for assessment of infectivity. The findings of this study provide information for improving the management of recovered patients, and for differentiating the follow-up of recovered patients with different risk levels.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/patologia , Pneumonia Viral/patologia , RNA Viral/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Betacoronavirus/isolamento & purificação , Criança , Pré-Escolar , Estudos de Coortes , Infecções por Coronavirus/genética , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/genética , Recidiva , Risco , Índice de Gravidade de Doença , Adulto Jovem
8.
Theranostics ; 10(13): 5704-5718, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32483413

RESUMO

Rationale: Epstein-Barr virus (EBV) is the causative pathogen for infectious mononucleosis and many kinds of malignancies including several lymphomas such as Hodgkin's lymphoma, Burkitt's lymphoma and NK/T cell lymphoma as well as carcinomas such as nasopharyngeal carcinoma (NPC) and EBV-associated gastric carcinoma (EBV-GC). However, to date no available prophylactic vaccine was launched to the market for clinical use. Methods: To develop a novel vaccine candidate to prevent EBV infection and diseases, we designed chimeric virus-like particles (VLPs) based on the hepatitis B core antigen (HBc149). Various VLPs were engineered to present combinations of three peptides derived from the receptor binding domain of EBV gp350. All the chimeric virus-like particles were injected into Balb/C mice for immunogenicity evaluation. Neutralizing titer of mice sera were detected using an in vitro cell model. Results: All chimeric HBc149 proteins self-assembled into VLPs with gp350 epitopes displayed on the surface of spherical particles. Interestingly, the different orders of the three epitopes in the chimeric proteins induced different immune responses in mice. Two constructs (149-3A and 149-3B) induced high serum titer against the receptor-binding domain of gp350. Most importantly, these two VLPs elicited neutralizing antibodies in immunized mice, which efficiently blocked EBV infection in cell culture. Competition analysis showed that sera from these mice contained antibodies to a major neutralizing epitope recognized by the strong neutralizing mAb 72A1. Conclusion: Our data demonstrate that HBc149 chimeric VLPs provide a valuable platform to present EBV gp350 antigens and offer a robust basis for the development of peptide-based candidate vaccines against EBV.

9.
Nat Commun ; 11(1): 2841, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32503989

RESUMO

The capsid of human papillomavirus (HPV) spontaneously arranges into a T = 7 icosahedral particle with 72 L1 pentameric capsomeres associating via disulfide bonds between Cys175 and Cys428. Here, we design a capsomere-hybrid virus-like particle (chVLP) to accommodate multiple types of L1 pentamers by the reciprocal assembly of single C175A and C428A L1 mutants, either of which alone encumbers L1 pentamer particle self-assembly. We show that co-assembly between any pair of C175A and C428A mutants across at least nine HPV genotypes occurs at a preferred equal molar stoichiometry, irrespective of the type or number of L1 sequences. A nine-valent chVLP vaccine-formed through the structural clustering of HPV epitopes-confers neutralization titers that are comparable with that of Gardasil 9 and elicits minor cross-neutralizing antibodies against some heterologous HPV types. These findings may pave the way for a new vaccine design that targets multiple pathogenic variants or cancer cells bearing diverse neoantigens.


Assuntos
Proteínas do Capsídeo/imunologia , Neoplasias/terapia , Papillomaviridae/imunologia , Infecções por Papillomavirus/terapia , Vacinas contra Papillomavirus/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Proteínas do Capsídeo/administração & dosagem , Proteínas do Capsídeo/genética , Desenho de Fármacos , Epitopos/genética , Epitopos/imunologia , Feminino , Humanos , Imunogenicidade da Vacina , Camundongos , Modelos Animais , Mutação , Neoplasias/virologia , Testes de Neutralização , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Vacinas contra Papillomavirus/administração & dosagem , Vacinas contra Papillomavirus/genética , Multimerização Proteica/genética , Multimerização Proteica/imunologia , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/genética , Vacinas de Partículas Semelhantes a Vírus/imunologia
10.
Brain Behav Immun ; 88: 39-43, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32464158

RESUMO

Self-reported depression has been observed in coronavirus disease-2019 (COVID-19) patients, infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), during discharge from the hospital. However, the cause of this self-reported depression during the convalescent period remains unclear. Here, we report the mental health status of 96 convalescent COVID-19 patients who were surveyed using an online questionnaire at the Shenzhen Samii Medical Center from March 2 to March 12, 2020 in Shenzhen, China. After obtaining their informed consent, we retrospectively analyzed the clinical characteristics of patients, including routine blood and biochemical data. The results suggested that patients with self-reported depression exhibited increased immune response, as indicated by increased white blood cell and neutrophil counts, as well as neutrophil-to-lymphocyte ratio. However, the mechanism linking self-reported depression to these cellular changes needs further study. In conclusion, self-reported depression occurred at an early stage in convalescent COVID-19 patients, and changes in immune function were apparent during short-term follow-up of these patients after discharge. Appropriate psychological interventions are necessary, and changes in immune function should be emphasized during long-term follow up of these patients.


Assuntos
Convalescença/psicologia , Infecções por Coronavirus/psicologia , Depressão/psicologia , Transtorno Depressivo/psicologia , Pneumonia Viral/psicologia , Adulto , Basófilos , Betacoronavirus , Proteína C-Reativa/imunologia , China , Infecções por Coronavirus/imunologia , Depressão/imunologia , Transtorno Depressivo/imunologia , Eosinófilos , Feminino , Humanos , Interleucina-6/imunologia , Tempo de Internação , Contagem de Leucócitos , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Monócitos , Neutrófilos , Pandemias , Pneumonia Viral/imunologia , Autorrelato , Índice de Gravidade de Doença , Adulto Jovem
11.
Nature ; 584(7819): 115-119, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32454513

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presents a global health emergency that is in urgent need of intervention1-3. The entry of SARS-CoV-2 into its target cells depends on binding between the receptor-binding domain (RBD) of the viral spike protein and its cellular receptor, angiotensin-converting enzyme 2 (ACE2)2,4-6. Here we report the isolation and characterization of 206 RBD-specific monoclonal antibodies derived from single B cells from 8 individuals infected with SARS-CoV-2. We identified antibodies that potently neutralize SARS-CoV-2; this activity correlates with competition with ACE2 for binding to RBD. Unexpectedly, the anti-SARS-CoV-2 antibodies and the infected plasma did not cross-react with the RBDs of SARS-CoV or Middle East respiratory syndrome-related coronavirus (MERS-CoV), although there was substantial plasma cross-reactivity to their trimeric spike proteins. Analysis of the crystal structure of RBD-bound antibody revealed that steric hindrance inhibits viral engagement with ACE2, thereby blocking viral entry. These findings suggest that anti-RBD antibodies are largely viral-species-specific inhibitors. The antibodies identified here may be candidates for development of clinical interventions against SARS-CoV-2.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Anticorpos Neutralizantes/química , Anticorpos Antivirais/química , Linfócitos B/citologia , Linfócitos B/imunologia , Betacoronavirus/química , Criança , Células Clonais/citologia , Células Clonais/imunologia , Reações Cruzadas , Cristalização , Cristalografia por Raios X , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Testes de Neutralização , Pandemias , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/metabolismo , Plasma/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo
12.
Med Sci Monit ; 26: e920520, 2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32188838

RESUMO

BACKGROUND Freshly isolated mouse embryonic fibroblasts (MEFs) have great proliferation capacity but quickly enter senescent state after several rounds of cell cycle, a process called premature senescence. Cellular senescence can be induced by various stresses such as telomere erosion, DNA damage, and oncogenic signaling. But the contribution of other molecules, such as growth factors, to cellular senescence is incompletely understood. This study aimed to compare the gene expression difference between non-senescent and senescent MEFs to identify the key molecule(s) involved in the spontaneous senescence of MEFs. MATERIAL AND METHODS Primary MEFs were isolated from E12.5 pregnant C57/BL6 mice. The cells were continuously cultured in Dulbecco's Modified Eagle Medium for 9 passages. SA-ß-Gal staining was used as an indicator of cell senescence. The supernatant from primary MEFs (P1 medium) or Passage 6 MEFs (P6 medium) were used to culture freshly isolated MEFs to observe the effects on cell senescence state. Gene expression profiles of primary and senescent MEFs were investigated by RNA-Seq to find the key genes involved in cell senescence. Adipocyte differentiation assay was used to evaluate the stemness of MEFs cultured in FGF2-stimulated medium. RESULTS The senescence of MEFs cultured in the P1 medium was alleviated when compared to the P6 medium. Downregulation of FGF2 expression was revealed by RNA-Seq and further confirmed by real-time quantitative polymerase chain reaction and western blot. FGF2-stimulated medium also had anti-senescence function and could maintain the differentiation ability of MEFs. CONCLUSIONS The premature senescence of MEFs was at least partially caused by FGF2 deficiency. Exogenous FGF2 could alleviate the senescent phenotype.


Assuntos
Senescência Celular/fisiologia , Fator 2 de Crescimento de Fibroblastos/metabolismo , Fibroblastos/metabolismo , Animais , Diferenciação Celular , Proliferação de Células , Dano ao DNA , Embrião de Mamíferos/metabolismo , Feminino , Perfilação da Expressão Gênica , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais
13.
Artigo em Inglês | MEDLINE | ID: mdl-31818956

RESUMO

In adaptive immunity, organisms produce neutralizing antibodies (nAbs) to eliminate invading pathogens. Here, we explored whether viral neutralization could be attained through the physical disruption of a virus upon nAb binding. We report the neutralization mechanism of a potent nAb 8C11 against the hepatitis E virus (HEV), a nonenveloped positive-sense single-stranded RNA virus associated with abundant acute hepatitis. The 8C11 binding flanks the protrusion spike of the HEV viruslike particles (VLPs) and leads to tremendous physical collision between the antibody and the capsid, dissociating the VLPs into homodimer species within 2 h. Cryo-electron microscopy reconstruction of the dissociation intermediates at an earlier (15-min) stage revealed smeared protrusion spikes and a loss of icosahedral symmetry with the capsid core remaining unchanged. This structural disruption leads to the presence of only a few native HEV virions in the ultracentrifugation pellet and exposes the viral genome. Conceptually, we propose a strategy to raise collision-inducing nAbs against single spike moieties that feature in the context of the entire pathogen at positions where the neighboring space cannot afford to accommodate an antibody. This rationale may facilitate unique vaccine development and antimicrobial antibody design.

14.
Emerg Microbes Infect ; 8(1): 1721-1733, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31769733

RESUMO

Human papillomavirus type 6 (HPV6) is the major etiologic agent of genital warts and recurrent respiratory papillomatosis. Although the commercial HPV vaccines cover HPV6, the neutralization sites and mode for HPV6 are poorly understood. Here, we identify the HPV6 neutralization sites and discriminate the inhibition of virus attachment and entry by three potent neutralizing antibodies (nAbs), 5D3, 17D5, and 15F7. Mutagenesis assays showed that these nAbs predominantly target surface loops BC, DE, and FG of HPV6 L1. Cryo-EM structures of the HPV6 pseudovirus (PsV) and its immune complexes revealed three distinct binding modalities - full-occupation-bound to capsid, top-center-bound-, and top-rim-bound to pentamers - and illustrated a structural atlas for three classes of antibody-bound footprints that are located at center-distal ring, center, and center-proximal ring of pentamer surface for 5D3, 17D5, and 15F7, respectively. Two modes of neutralization were identified: mAb 5D3 and 17D5 block HPV PsV from attaching to the extracellular matrix (ECM) and the cell surface, whereas 15F7 allows PsV attachment but prohibits PsV from entering the cell. These findings highlight three neutralization sites of HPV6 L1 and outline two antibody-mediated neutralization mechanisms against HPV6, which will be relevant for HPV virology and antiviral inhibitor design. HighlightsMajor neutralization sites of HPV6 were mapped on the pseudovirus cryo-EM structuremAb 15F7 binds HPV6 capsid with a novel top-rim binding modality and confers a post-attachment neutralizationmAb 17D5 binds capsid in top-centre manner but unexpectedly prevents virus from attachment to cell surface.


Assuntos
Papillomavirus Humano 6/fisiologia , Infecções por Papillomavirus/virologia , Ligação Viral , Internalização do Vírus , Animais , Anticorpos Neutralizantes/análise , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/análise , Anticorpos Antivirais/imunologia , Epitopos/genética , Epitopos/imunologia , Papillomavirus Humano 6/genética , Papillomavirus Humano 6/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Infecções por Papillomavirus/imunologia
15.
Int J Syst Evol Microbiol ; 69(3): 816-820, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30694172

RESUMO

A Gram-stain-negative, rod-shaped (0.2-0.4 µm×1.2-1.7 µm), endophytic bacterium, designated HBUM179779T, was isolated from the stem of a medicinal plant,Gynura bicolor, collected from Pixian county in Sichuan province, China. The strain did not produce endospores and its cells could secrete mucus. The predominant menaquinone was MK-7. The polar lipids were phosphatidylethanolamine, phosphatidylinositolmannosides, two unknown aminolipids, two unknown glycolipids and an unknown phospholipid. Branched fatty acids (iso-) and hydroxy fatty acids were the main fatty acids, which mainly included iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HBUM179779T fell within the family Chitinophagaceae, and its closest neighbour was Pseudoflavitalea rhizosphaerae T16R-265T (94.46 %). However, strain HBUM179779T did not make a coherent clade with members of the recognized organisms. The average nucleotide identity value between strain HBUM179779T and Pseudoflavitalea rhizosphaerae T16R-265T was 67.1 %. On the basis of the phylogenetic and phenotypic characteristics of this bacterium, a novel genus and species, Gynurincola endophyticus gen. nov., sp. nov., is proposed. The type strain is HBUM179779T (=CGMCC 1.15525T=NBRC 112424T).


Assuntos
Asteraceae/microbiologia , Bacteroidetes/classificação , Filogenia , Caules de Planta/microbiologia , Técnicas de Tipagem Bacteriana , Bacteroidetes/isolamento & purificação , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , Plantas Medicinais/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
16.
FASEB J ; 33(4): 4883-4892, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30592645

RESUMO

Clostridium difficile is associated with antibiotic-associated diarrhea and pseudomembranous colitis in humans. Its 2 major toxins, toxins A and B, enter host cells and inactivate GTPases of the Ras homologue/rat sarcoma family by glucosylation. Pore formation of the toxins in the endosomal membrane enables the translocation of their glucosyltransferase domain into the cytosol, and membrane cholesterol is crucial for this process. Here, we asked whether the activity of the sterol regulatory element-binding protein 2 (SREBP-2) pathway, which regulates the cholesterol content in membranes, affects the susceptibility of target cells toward toxins A and B. We show that the SREBP-2 pathway is crucial for the intoxication process of toxins A and B by using pharmacological inhibitors (PF-429242, 25-hydroxycholesterol) and cells that are specifically deficient in SREBP-2 pathway signaling. SREBP-2 pathway inhibition disturbed the cholesterol-dependent pore formation of toxin B in cellular membranes. Preincubation with the cholesterol-lowering drug simvastatin protected cells from toxin B intoxication. Inhibition of the SREBP-2 pathway was without effect when the enzyme portion of toxin B was introduced into target cells via the cell delivery property of anthrax protective antigen. Taken together, these findings allowed us to identify the SREBP-2 pathway as a suitable target for the development of antitoxin therapeutics against C. difficile toxins A and B.-Papatheodorou, P., Song, S., López-Ureña, D., Witte, A., Marques, F., Ost, G. S., Schorch, B., Chaves-Olarte, E., Aktories, K. Cytotoxicity of Clostridium difficile toxins A and B requires an active and functional SREBP-2 pathway.


Assuntos
Proteínas de Bactérias/farmacologia , Toxinas Bacterianas/farmacologia , Enterotoxinas/farmacologia , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo , Animais , Células CHO , Linhagem Celular , Cricetulus , Células HeLa , Humanos , Hidroxicolesteróis/farmacologia , Camundongos , Pirrolidinas/farmacologia , Transdução de Sinais/efeitos dos fármacos
17.
Nat Commun ; 9(1): 5360, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30560935

RESUMO

Sequence variability in surface-antigenic sites of pathogenic proteins is an important obstacle in vaccine development. Over 200 distinct genomic sequences have been identified for human papillomavirus (HPV), of which more than 18 are associated with cervical cancer. Here, based on the high structural similarity of L1 surface loops within a group of phylogenetically close HPV types, we design a triple-type chimera of HPV33/58/52 using loop swapping. The chimeric VLPs elicit neutralization titers comparable with a mix of the three wild-type VLPs both in mice and non-human primates. This engineered region of the chimeric protein recapitulates the conformational contours of the antigenic surfaces of the parental-type proteins, offering a basis for this high immunity. Our stratagem is equally successful in developing other triplet-type chimeras (HPV16/35/31, HPV56/66/53, HPV39/68/70, HPV18/45/59), paving the way for the development of an improved HPV prophylactic vaccine against all carcinogenic HPV strains. This technique may also be extrapolated to other microbes.


Assuntos
Desenho de Fármacos , Papillomaviridae/imunologia , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/imunologia , Neoplasias do Colo do Útero/prevenção & controle , Animais , Anticorpos Antivirais/genética , Anticorpos Antivirais/imunologia , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Avaliação Pré-Clínica de Medicamentos , Epitopos/genética , Epitopos/imunologia , Feminino , Engenharia Genética/métodos , Imunogenicidade da Vacina , Macaca fascicularis , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais , Testes de Neutralização , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/imunologia , Papillomaviridae/genética , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/virologia , Vacinas contra Papillomavirus/genética , Filogenia , Organismos Livres de Patógenos Específicos , Neoplasias do Colo do Útero/imunologia , Neoplasias do Colo do Útero/virologia
18.
Emerg Microbes Infect ; 7(1): 160, 2018 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-30254257

RESUMO

Human papillomavirus (HPV) is the causative agent in genital warts and nearly all cervical, anogenital, and oropharyngeal cancers. Nine HPV types (6, 11, 16, 18, 31, 33, 45, 52, and 58) are associated with about 90% of cervical cancers and 90% of genital warts. HPV neutralization by vaccine-elicited neutralizing antibodies can block viral infection and prevent HPV-associated diseases. However, there is only one commercially available HPV vaccine, Gardasil 9, produced from Saccharomyces cerevisiae that covers all nine types, raising the need for microbial production of broad-spectrum HPV vaccines. Here, we investigated whether N-terminal truncations of the major HPV capsid proteins L1, improve their soluble expression in Escherichia coli. We found that N-terminal truncations promoted the soluble expression of HPV 33 (truncated by 10 amino acids [aa]), 52 (15 aa), and 58 (10 aa). The resultant HPV L1 proteins were purified in pentamer form and extensively characterized with biochemical, biophysical, and immunochemical methods. The pentamers self-assembled into virus-like particles (VLPs) in vitro, and 3D cryo-EM reconstructions revealed that all formed T = 7 icosahedral particles having 50-60-nm diameters. Moreover, we formulated a nine-valent HPV vaccine candidate with aluminum adjuvant and L1 VLPs from four genotypes used in this study and five from previous work. Immunogenicity assays in mice and non-human primates indicated that this HPV nine-valent vaccine candidate elicits neutralizing antibody titers comparable to those induced by Gardasil 9. Our study provides a method for producing a nine-valent HPV vaccine in E. coli and may inform strategies for the soluble expression of other vaccine candidates.


Assuntos
Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Escherichia coli/genética , Proteínas Oncogênicas Virais/química , Proteínas Oncogênicas Virais/genética , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Motivos de Aminoácidos , Animais , Anticorpos Antivirais/imunologia , Proteínas do Capsídeo/administração & dosagem , Proteínas do Capsídeo/imunologia , Escherichia coli/metabolismo , Feminino , Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Oncogênicas Virais/administração & dosagem , Proteínas Oncogênicas Virais/imunologia , Papillomaviridae/química , Papillomaviridae/imunologia , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/administração & dosagem , Vacinas contra Papillomavirus/química , Vacinas contra Papillomavirus/genética , Vacinas contra Papillomavirus/imunologia , Deleção de Sequência
19.
Front Immunol ; 9: 932, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29765376

RESUMO

Epstein-Barr virus (EBV) was the first human virus proved to be closely associated with tumor development, such as lymphoma, nasopharyngeal carcinoma, and EBV-associated gastric carcinoma. Despite many efforts to develop prophylactic vaccines against EBV infection and diseases, no candidates have succeeded in effectively blocking EBV infection in clinical trials. Previous investigations showed that EBV gp350 plays a pivotal role in the infection of B-lymphocytes. Nevertheless, using monomeric gp350 proteins as antigens has not been effective in preventing infection. Multimeric forms of the antigen are more potently immunogenic than monomers; however, the multimerization elements used in previous constructs are not approved for human clinical trials. To prepare a much-needed EBV prophylactic vaccine that is potent, safe, and applicable, we constructed an Fc-based form of gp350 to serve as a dimeric antigen. Here, we show that the Fc-based gp350 antigen exhibits dramatically enhanced immunogenicity compared with wild-type gp350 protein. The complete or partial gp350 ectodomain was fused with the mouse IgG2a Fc domain. Fusion with the Fc domain did not impair gp350 folding, binding to a conformation-dependent neutralizing antibody (nAb) and binding to its receptor by enzyme-linked immunosorbent assay and surface plasmon resonance. Specific antibody titers against gp350 were notably enhanced by immunization with gp350-Fc dimers compared with gp350 monomers. Furthermore, immunization with gp350-Fc fusion proteins elicited potent nAbs against EBV. Our data strongly suggest that an EBV gp350 vaccine based on Fc fusion proteins may be an efficient candidate to prevent EBV infection in clinical applications.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções por Vírus Epstein-Barr/imunologia , Herpesvirus Humano 4/imunologia , Fragmentos Fc das Imunoglobulinas/imunologia , Proteínas Recombinantes de Fusão , Proteínas Virais/imunologia , Adjuvantes Imunológicos , Animais , Humanos , Imunidade Humoral , Imunização , Imunoglobulina A/imunologia , Fragmentos Fc das Imunoglobulinas/química , Fragmentos Fc das Imunoglobulinas/genética , Imunoglobulina G/imunologia , Cinética , Camundongos , Camundongos Endogâmicos BALB C , Ligação Proteica/imunologia , Multimerização Proteica , Proteínas Virais/química , Proteínas Virais/genética
20.
Sci Adv ; 3(9): e1700555, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28959726

RESUMO

Transforming a laser beam into a mass flow has been a challenge both scientifically and technologically. We report the discovery of a new optofluidic principle and demonstrate the generation of a steady-state water flow by a pulsed laser beam through a glass window. To generate a flow or stream in the same path as the refracted laser beam in pure water from an arbitrary spot on the window, we first fill a glass cuvette with an aqueous solution of Au nanoparticles. A flow will emerge from the focused laser spot on the window after the laser is turned on for a few to tens of minutes; the flow remains after the colloidal solution is completely replaced by pure water. Microscopically, this transformation is made possible by an underlying plasmonic nanoparticle-decorated cavity, which is self-fabricated on the glass by nanoparticle-assisted laser etching and exhibits size and shape uniquely tailored to the incident beam profile. Hydrophone signals indicate that the flow is driven via acoustic streaming by a long-lasting ultrasound wave that is resonantly generated by the laser and the cavity through the photoacoustic effect. The principle of this light-driven flow via ultrasound, that is, photoacoustic streaming by coupling photoacoustics to acoustic streaming, is general and can be applied to any liquid, opening up new research and applications in optofluidics as well as traditional photoacoustics and acoustic streaming.

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