Mechanism of Learning and Memory Impairment in Rats Exposed to Arsenic and/or Fluoride Based on Microbiome and Metabolome / 生物医学与环境科学（英文）

OBJECTIVE@#Arsenic (As) and fluoride (F) are two of the most common elements contaminating groundwater resources. A growing number of studies have found that As and F can cause neurotoxicity in infants and children, leading to cognitive, learning, and memory impairments. However, early biomarkers of learning and memory impairment induced by As and/or F remain unclear. In the present study, the mechanisms by which As and/or F cause learning memory impairment are explored at the multi-omics level (microbiome and metabolome).@*METHODS@#We stablished an SD rats model exposed to arsenic and/or fluoride from intrauterine to adult period.@*RESULTS@#Arsenic and/fluoride exposed groups showed reduced neurobehavioral performance and lesions in the hippocampal CA1 region. 16S rRNA gene sequencing revealed that As and/or F exposure significantly altered the composition and diversity of the gut microbiome，featuring the Lachnospiraceae_NK4A136_group, Ruminococcus_1, Prevotellaceae_NK3B31_group, [Eubacterium]_xylanophilum_group. Metabolome analysis showed that As and/or F-induced learning and memory impairment may be related to tryptophan, lipoic acid, glutamate, gamma-aminobutyric acidergic (GABAergic) synapse, and arachidonic acid (AA) metabolism. The gut microbiota, metabolites, and learning memory indicators were significantly correlated.@*CONCLUSION@#Learning memory impairment triggered by As and/or F exposure may be mediated by different gut microbes and their associated metabolites.

[Effect of glucose analogs on bofilm and expressions of related genes in Staphylococcus epidermidis].

Staphylococcus epidermidis, an opportunistic human pathogen, has become the most important cause of nosocomial infections in recent years. Its infection is mainly due to the ability to form biofilm on indwelling medical devices. To investigate the response mechanism of S. epidermidis to environment in biofilm formation and find efficient anti-biofilm methods, we investigated effects of two glucose analogs, 2-Deoxy-D-glucose (2DG) and Methyl-D-glucoside (MG), on biofilm formation, expression of related gene and changes of surface protein in S. epidermidis 97-337 with high biofilm formation capability and pathogenicity. The effect of MG on biofilm formation was more complex than that of 2-DG which is a strong inhibitor in S. epidermidis 97-337 growth. MG can induce biofilm formation of S. epidermidi 97-337 in low concentration and exhibited strong inhibition only in high concentration, and distinctly inhibited the primary attachment to poly-material. In S. epidermidi 97-337 cultured in media with MG, expressions of ica and AtlE were not be changed obviously in mRNA level, but mRNA expression of agr gene increased distinctly, and MG disturbed component of surface proteins of S. epidermidi 97-337. Glucose analogies MG can inhibit S. epidermidi 97-337 biofilm formation, and MG inhibition in initiating attachment dramatically contributes to it. MG inhibition effects result not from regulating the expression of ica and AtlE genes but from changing the protein components on surface by regulating agr gene expression, and it can be presumed that MG's competitive character in bacteria glycose metabolism is crucial factor for these effects.

Pneumoperitoneum simulation based on mass-spring-damper models for laparoscopic surgical planning.

Laparoscopic surgery, which is one minimally invasive surgical technique that is now widely performed, is done by making a working space (pneumoperitoneum) by infusing carbon dioxide ([Formula: see text]) gas into the abdominal cavity. A virtual pneumoperitoneum method that simulates the abdominal wall and viscera motion by the pneumoperitoneum based on mass-spring-damper models (MSDMs) with mechanical properties is proposed. Our proposed method simulates the pneumoperitoneum based on MSDMs and Newton's equations of motion. The parameters of MSDMs are determined by the anatomical knowledge of the mechanical properties of human tissues. Virtual [Formula: see text] gas pressure is applied to the boundary surface of the abdominal cavity. The abdominal shapes after creation of the pneumoperitoneum are computed by solving the equations of motion. The mean position errors of our proposed method using 10 mmHg virtual gas pressure were [Formula: see text], and the position error of the previous method proposed by Kitasaka et al. was 35.6 mm. The differences in the errors were statistically significant ([Formula: see text], Student's [Formula: see text]-test). The position error of the proposed method was reduced from [Formula: see text] to [Formula: see text] using 30 mmHg virtual gas pressure. The proposed method simulated abdominal wall motion by infused gas pressure and generated deformed volumetric images from a preoperative volumetric image. Our method predicted abdominal wall deformation by just giving the [Formula: see text] gas pressure and the tissue properties. Measurement of the visceral displacement will be required to validate the visceral motion.

Advances in two-component signal transduction system VraSR of Staphylococcus / 中华微生物学和免疫学杂志

Staphylococcus utilizes vancomycin-resistance associated sensor/regulator ( VraSR) , a two-component signal transduction system ( TCS) , to sense and respond to cell wall damage and to adapt to environmental changes through regulating transcriptions of downstream genes. It has been indicated that VraSR can regulate the transcription of a series of genes involved in the synthesis of peptidoglycan, drug re-sistance, and virulence in Staphylococcus aureus ( S. aureus) . A similar two-component system, VraSR, is also present in Staphylococcus epidermidis ( S. epidermidis ) , sharing a high homology with the VraSR of S. aureus. Little is known about the functions of VraSR in S. epidermidis and it is not yet clear what the simi-larities and differences in resistance and pathogenicity are. Based on the previous work of our group, a brief review on the regulation mechanism of staphylococcal VraSR was performed.

Filamentation initiated by Cas2 and its association with the acquisition process in cells / 国际口腔科学杂志·英文版

Cas1-and-Cas2-mediated new spacer acquisition is an essential process for bacterial adaptive immunity. The process is critical for the ecology of the oral microflora and oral health. Although molecular mechanisms for spacer acquisition are known, it has never been established if this process is associated with the morphological changes of bacteria. In this study, we demonstrated a novel Cas2-induced filamentation phenotype in E. coli that was regulated by co-expression of the Cas1 protein. A 30 amino acid motif at the carboxyl terminus of Cas2 is necessary for this function. By imaging analysis, we provided evidence to argue that Cas-induced filamentation is a step coupled with new spacer acquisition during which filaments are characterised by polyploidy with asymmetric cell division. This work may open new opportunities to investigate the adaptive immune response and microbial balance for oral health.

Effects of ginseng neutral polysaccharide on gut microbiota in antibiotic-associated diarrhea mice / 中国中药杂志

To investigate the effect of ginseng neutral polysaccharide on gut microbiota composition and diversity as well as the therapeutic effect for antibiotic associated diarrhea( AAD) in mice. The water-soluble ginseng neutral polysaccharide( WGPN) was purified from water-soluble ginseng polysaccharides( WGP) by DEAE-sepharose fast flow column,which was obtained from the roots of Panax ginseng. AAD mice were induced by gastric gavage with lincomycin hydrochloride,followed by administration of normal saline( natural recovery group,NR) or WGPN( WGPN group) for one week. Body weight changes,psychosis and diarrhea status were observed and assessed. 12 h after the last administration,histological observation of ileum and 16 S rRNA high throughput sequencing analysis of intestinal contents were conducted to identify the effects of WGPN on AAD mice. The results showed that WGPN could alleviate the symptoms of diarrhea in mice,decrease the inflammation and edema of ileum,and increase the length of intestinal villi. As compared to NR mice,WGPN could increase the relative abundance of Lactobacillus,and significantly decrease the relative abundance of Bacteroides,Streptococcus,Ochrobactrum and Pseudomonas at the genus level. In conclusion,WGPN could improve the gut microecology by recovering the ileum structure and improving the diversity and composition of the gut microbiota in AAD mice.

Investigation on the status of 3-14 years old children with cerebral palsy in Liaoning / 中国医师进修杂志

Objective To investigate the status on children of 3-14 years old who suffered from cerebral palsy in Liaoning province. Methods One thousand three hundred and twenty-three cases of children with cerebral palsy of 3-14 years old who received rehabilitation in city hospital, county hospital and community hospital were investigated from January 2013 to October 2016 in 14 cities in Liaoning Province. The proportion of cerebral palsy children in 3-4 years old, 4-5 years old, 8-9 years old, 5-6 years old , 6-7 years old and 7-8 years old was about 10%, and in the other age the proportion was about 7%. The proportion of men and women generally was 4:1;neonatal convulsion (252 cases, 19%), premature delivery (230 cases , 17.3%) and low birth weight infant (187 cases, 14.1%) were main risk factors and accounted for more than 10%. Spastic type cerebral palsy accounted for the highest proportion (54.35%, 719 cases)and ataxia cerebral palsy accounted for the lowest proportion (2.95%). In complications , lower intelligence accounted for the highest proportion (50.34%, 666 cases), followed by the language barrier (43.99% , 582 cases), and the other complications accounted for less than 10%.;gross motor function classification in most studied children was stageⅡ(35%) and stageⅢ(32.50%); 6.95% patients could go to school, and 84.96% patients had health insurance. Patients coming from city accounted for 69.01%, and patients coming from rural area accounted for 30.99%. Mothers′ education below primary school was 4.16% . 36.05% children received rehabilitation in comprehensive hospital, 60.09%in children′s hospital and 3.85%in maternal and child health hospital. Conclusions Spastic cerebral palsy is the main type of children with cerebral palsy in Liaoning.High risk factors include neonatal convulsions, premature birth and low birth weight infants. Most patients complicate with low intelligence and language barriers.This paper can be used as the basis of further research on prevention and treatment

Effect of bevacizumab on proliferation and invasion of human lung cancer A549 cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the effect and mechanism of bevacizumab on proliferation and invasion of human lung cancer A549 cells.</p><p><b>METHODS</b>A549 cells were treated with bevacizumab. Proliferation and invasion of the bevacizumab-treated A549 cells were detected using cell counting kit CCK-8 and Transwell assay, respectively. The expression of the mRNA and protein of MMP-2, MMP-9 and c-Met were detected by real-time PCR and Western blotting, respectively.</p><p><b>RESULTS</b>Proliferation activity was inhibited at the concentration of 10 µg/ml and promoted at the concentration of 100 µg/ml bevacizumab. Bevacizumab in the concentration of 50 µg/ml had a stronger inhibitory effect on the invasion of A549 cells (16 406.19 ± 5 674.23 penetrated cells) than that of control group (36 108.68 6 263.83, P<0.05). The real-time PCR showed that bevacizumab had a stronger inhibitory effect on the expression of MMP-2 and MMP-9 mRNA at the concentration of 50 µg/ml and on the expression c-Met mRNA at the concentration of 10 µg/ml bevacizumabin the A549 cells. However bevacizumab at the concentration of 100 µg/ml showed a promoting effect on the expression of MMP-2, MMP-9 and c-Met mRNA (1.82 ± 0.31, 1.60 ± 0.25, 2.63 ± 0.48), significantly higher than that of the control group (1.00 ± 0.19, 1.00 ± 0.23, 1.00 ± 0.22, P<0.05). The expression of MMP-2, MMP-9 and c-Met mRNA and protein was inhibited by 10 µg/ml bevacizumab in a time-dependent manner. The Western blot assay showed that bevacizumab had a bi-directional effect on the expression of MMP-2 and c-Met proteins in the A549 cells: a promoting effect at 100 µg/ml and inhibitory effect on the expression of MMP-2 at 50 µg/ml bevacizumab, and inhibitory effect on the expression of c-Met protein at 10 µg/ml bevacizumab.</p><p><b>CONCLUSIONS</b>Our findings indicate that in a certain range of concentrations, bevacizumab has prominent inhibitory effect on the proliferation and invasion of A549 cells. However,over the concentration of 100 µg/ml, bevacizumab shows a weakening anti-invasion effect, even has a promoting effect on cell proliferation. This phenomenon may be related to the inhibiting effect on the expression of MMP-2 and c-Met proteins in a non-concentration-dependent manner by bevacizumab.</p>

Analysis on job stress assessment in BSL-3 laboratories / 中国比较医学杂志

Objective The staffs of biosafety level 3 laboratories (BSL-3) face with the stress of handling highly pathogenic microbs and special laboratory environment.The job stress may result in accidents in the laboratory as negative factor for the risk control.The research may provide support for the control of risk in biosafety laboratories.Methods In order to assess the job stress in the staff in BSL-3 laboratory, we modified “the Chinese simple job stress questionnaire”based on the theory of the JDC mode and ERI mode, and an investigation was carried out.The present study included the staffs (87 employees) from six BSL-3 laboratories located in five provinces ( Shanghai, Zhejiang, Jiangsu, Fujian and Wuhan) .Results Analysis of the data indicates that variables of age, working years, job duties, manipulating of animals, type of microorganisms and transmission route have a significant influence on the level of job stress in BSL-3 laboratory.Conclusion The BSL-3 laboratory staff in higher stress level have the characteristicses:20-39 years old, short work years, regular staff, operating on air-borne microbiology, manipulating of animals and operating on one more microbiology.

Expression profiles of IL-10, TNF-a, and SOCS3 in placenta of pregnant women with intrahepatic cholestasis / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To detect the expression profiles of suppressor of cytokine signaling 3 (SOCS3), interleukin (IL)-10, and tumor necrosis factor-alpha (TNF-a) in the placenta of women with intrahepatic cholestasis of pregnancy (ICP) and determine the clinical significance of the differential expressions.</p><p><b>METHODS</b>Placentas were collected from 37 ICP gravidas who delivered through cesarean section at the First Teaching Hospital of Xingjiang Medical University from October 2010 to May 2011 and from 35 healthy pregnant women (controls). SOCS3, TNF-a, and IL-10 protein levels were detected by immunoblotting and the Envision immunohistochemical method.</p><p><b>RESULTS</b>TNF-a and IL-10 expression was detected in placentas of both groups, and was present mainly in the cytoplasm of trophoeytes. IL-10 expression was obviously lower in the ICP placentas than in the control placentas; meanwhile, TNF-a expression was obviously higher than in the control placentas (Z=-2.63, P less than 0.01). SOCS3 protein was significantly more abundant in the control placentas than in the ICP placentas. Furthermore, SOCS3 and IL-10 placental expressions were positively correlated (r=0.494, P less than 0.01), but there was a negative correlation between SOCS3 and TNF-a placental expressions (r=-0.472, P less than 0.01).</p><p><b>CONCLUSION</b>In ICP, an increase of the type 1 cytokine, TNF-a, is associated with decreases of the type 2 cytokine, IL-10, and of SOCS3, which may reduce the secretion of IL-10. Furthermore, SOCS3 may contribute to ICP pathogenesis by modulating the Th1/Th2 cytokine balance.</p>

The molecular characteristics and virulence factor of Methicillin-resistant Staphylococcus aureus isolatedfrom pediatric patients / 中华传染病杂志

Objective To investigate the molecular characteristic,the virulence factors and antimicrobial resistance of Methicillin-resistant Staphylococcus aureus (MRSA) isolated from pediatric patients.Methods Ninety-eight non-duplicate strains of and 49 non-duplicate strains of Methicillinsusceptible Staphylococcus aureus (MSSA) isolated from the three children's hospitals in Shanghai in 2008 were investigated.Panton-valentine leukocidin (PVL) gene was detected by polymerase chain reaction (PCR).The genotypes of staphylococcal cassette chromosome mec (SCCmec) of the MRSA isolates were confirmed by multiplex PCR.The sequence type (ST) of each strain was determined by multilocus sequence typing (MLST),and the algorithm eBURST was used to identify groups of clonal complex (CC).The minimal inhibitory concentrations (MIC) of fourteen antibiotics for all isolates were determined by agar dilution method.Results Among 98 isolates of MRSA,the positive rate of PVL genes was 6.1％ (6/98).In contrast,the positive rate of PVL genes was 4.1％ (2/48) of the MSSA strains.Among 98 isolates of MRSA,4.1％ (4/98),23.5％ (23/98),53.0％ (52/98) and 15.3％ (15/98) of the strains harboured SCCmec types Ⅱ,Ⅲ,Ⅳ and Ⅴ,respectively. The remaining four isolates (4.1 ％) presented a unique SCCmec pattern that could not be classified to any known types by the employed typing assays.Combining the ST and SCCmec type,the predominant clones were ST59-SCCmec Ⅳ (30 strains) and ST239-SCCmec Ⅲ (23 strains),followed by ST5-SCCmecⅣ and ST1-SCCmecⅣ (8 strains for each clone),ST239-SCCmec Ⅴ (6 strains),ST88-SCCmecⅤ (5 strains),ST5 SCCmecⅡ (4 strains),ST59-SCCmec Ⅴ (3 strains),ST8-SCCmecⅣ and ST88-SCCmecⅣ (2 strains for each clone),ST22-SCCmecⅣ,ST910-SCCmecⅣ and S45-SCCmec Ⅴ (1 strain for each clone),eBURST analysis distributed the MRSA isolates into several CC.ST8 and ST239 belonged to ST8 CC,ST1 belonged to ST15 CC,ST910 belonged to ST 30 CC,ST59,ST5,ST88,ST45,ST22,ST9 and ST7 were the origin of their own CC.The results of MIC showed that the 67 strains of MRSA harboring SCCmec type Ⅳ or SCCmec type Ⅴ were more susceptible to various non-β-lactam antibiotics than 27 strains of MRSA harboring SCCmec type Ⅱ or SCCmec type Ⅲ,and no vancomycin-resistant strain was found.Conclusions In three children's hospitals in Shanghai,the PVL gene-positive rate of MRSA isolates is relatively low,SCCmec type Ⅳ and SCCmec type Ⅴ could spread among hospitals to cause a small scale epidemic and have a variety of ST.

β-lactamase genotyping of multi-drug resistant Acinetobacter baumannii in a neonatal intensive care unit / 中华围产医学杂志

Objective To investigate the correlation between drug resistance and β-actamase genes of multi-drug resistance Acinetobacter baumannii (MDR-AB) in neonatal intensive care unit to provide evidence for rational antibiotics administration and nosocomial infection control.Methods Twenty-six MDR-AB strains were separated and collected from clinical specimens.The minimum inhibitory concentrations of 13 antimicrobial agents were determined by agar dilution method.Genotypes of β-lactamase were detected by polymerase chain reaction.Results The resistant rates of the 26 strains to Ceftazidime,Cefoxitin,Piperacillin-tazobactam and Ciprofloxacin were 100.0%.About 80.8% to 96.2% of these strains were resistant to the other antimicrobial drugs.Among the 26 MDR-AB strains,100% (26/26) strains possessed oxa-51,77% (20/26) possessed oxa-23 gene,54% (14/26) carried arnpC gene,both oxa-23 and ampC were identified in 42% (11/26) strains,while oxa-24,oxa-58,imp-1,imp-4 and vim-2 gene were not identified.Conclusions The drug resistance of Acinetobacter baumannii is serious,oxa-23 and ampC are the major plactamase genes carried by MDR-AB in neonatal intensive care unit.

The immunoregulation of andrographolide on peripheral blood mononuclear cells from patients with chronic hepatitis B / 中华传染病杂志

Objective To investigate the effects of andrographolide on the expressions of Th1 cytokine [interferon (IFN)-γ] mRNA and Th2 cytokines [interleukin (ID-4, IL-10] mRNA of peripheral blood mononuclear cells (PBMCs) from patients with chronic hepatitis B (CHB) and its anti-hepatitis B virus (HBV) activity. Methods PBMCs from CHB patients were cultured with 10 mg/L andrographolide (experimental group) or 0.1% DMSO (control group). HepG2. 2. 15 cells were stimulated with andrographolide of different concentrations (experimental group) or adefovir (control group). The expressions of IFN-γ mRNA, IL-4 mRNA and IL-10 mRNA of PBMCs and the replication of HBV DNA in HepG2. 2. 15 cell line were detected by fluorescence quantitative PCR. Results The expression of IFN-γ mRNA in PBMCs cultured with 10 mg/L andrographolide for 16 h was higher than that in control group (Z=-2. 78, P=0. 05), and the expressions of IL-4 and IL-10mRNA in experimental group were lower than control group (Z= -3. 82, P<0. 01), while the ratio of IFN-γ/IL-4 mRNA was higher than control group (Z= - 3. 82, P<0. 01). Andrographolide with different concentrations had no effect on the replication of HBV DNA in HepG2. 2.15 cells ((=11. 88, P>0.05). However, adefovir had inhibitory effect on the replication of HBV DNA (t =15. 95,P< 0. 05). Conclusion Andrographolide can regulate the expressions of IFN-γ mRNA, IL-4 mRNA and IL-10 mRNA in PBMCs from CHB patients and improve Thl/Th2 balance, while it has no effect on the replication of HBV DNA.

Effects of andrographolide on the expression of IL-18 related cytokines in human PBMC/PBM / 中国免疫学杂志

Objective:To study the effects of andrographolide on the expression of IL-18 related cytokines by peripheral blood monocytes.Methods:After treatment of andrographolide in different concentrations on LPS stimulated human peripheral blood mononuclear cells (PBMC) and LPS+IFN-γ/IL-4 activated magnetic bead-sorted monocytes (PBM),the transcription level of IL-18,IL-18BP,IL-18Rα and IL-18Rβ was detected by real-time RT-PCR;and secreted IL-18,IL-18BP and IL-1β,IL-1Rα by PBM was detected with ELISA.Results:Andrographolide regulated the transcription of IL-18 and IL-18BP in a dose-and time-dependent effect.Andrographolide up-regulated the transcription of IL-18BP in LPS stimulated PBMC,and increased the ratio of IL-18BP/IL-18.The ratio of IL-18BP/IL-18 rose from 9.60 to 214 in LPS+IFNγ activated PBM,and IL-1Rα/IL-1β declined from 9 200 to 6 520 in IL-4 activated PBM by andrographolide treatment.Conclusion:Andrographolide can regulate IL-18 related gene transcription and expression in activated peripheral blood monocytes,and inhibit the excessive expression of IL-18 during inflammation.

Molecular epidemiology and detection of clinical isolates of Klebsiella pneumoniae producing plasmid-mediated 16S rRNA methylases / 中华检验医学杂志

Objective To investigate the prevalence and molecular epidemiology of clinical isolates of plasmid-mediated 16S rRNA methylases-producing Klebsiella pneumoniae. Methods From January 2006 and September 2007, 337 non-replicate clinical isolates of Klebsiella pneumoniae were consecutively collected from inpatients in a teaching hospital in Wenzhou, China. All of the isolates were identified by the automated microbiology systems. MICs of amikacin, gentamicin and tobramycin were determined by agar dilution method. The isolates were investigated for the presence of ESBLs by the CLSI-recommended confirmatory tests. PCR was used to detect 16S rRNA methylase genes, ESBL genes and class Ⅰ integrase gene. The homology of these isolates was analyzed by pulse-field gel electrophoresis (PFGE). Results Sixty-four ( 19. 0% ), 28 ( 8. 3% ) and 55 ( 16. 3% ) of 337 isolates were resistant to gentamicin, amikacin and tobramycin, respectively. Twenty-one (6. 2% ) isolates carried 16S rRNA methylase genes (3 for armA, 13 for rmtB, 5 for both armA and rmtB) and high-level resistant to gentamicin, amikacin and tobramycin ( MICs ≥256 mg/L). Nineteen of 21 isolates with 16S rRNA methylase genes were ESBL producers, blaCTX-M-14-like, blaCTX-M-like and blaSHV-12-like were predominant genotypes of ESBLs. The plasmids of 13 isolates were transferred into the recipients E. co/iJ53. PCR and sequence analysis revealed that blaCTX-M-14-like,blaCTX-M-15-like and blaSHV-12-like were co-transferred with the armA or the rmtB to the recipients. All transconjugants harbored intll and blaTEN-1. Of the 21 isolates, 14 patterns were obtained by PFGE. Conclusion Both horizontal gene transfer and clonal spread were responsible for the dissemination of the rmtB or the armA gene in Klebsiella pneumoniae.

Preliminary study on DNA immunization with hantavirus envelope glycoprotein genes G1 and G2 / 中华传染病杂志

Objective To examine whether hantavirus Z37 envelope glycoprotein genes G1 and G2 recombinants could elicit humoral immune responses in mice. Methods We vaccinated BALB/C mice with plasmid pcDNA3.1 G1 and pcDNA3.1 G2 respectively by intramuscular and gene gun inoculation. Serum anti hantavirus antibodies were detected by IFA and neutralizing antibodies (NAb) were detected by plaque reduction neutralization test with immunoperoxidase staining. The mice given intramuscular inoculation were divided into 3 groups, each group containing 5 mice: groupⅠas control inoculated with 100 ?g pcDNA3.1 ; groupⅡ with 100 ?g pcDNA3.1 G1; group Ⅲ with 100 ?g pcDNA3.1 G2. Each mouse was immunized three times. 4 weeks after primary vaccination, 2 boosts were given at 3 week intervals. The mice given gene gun inoculation were divided into 3 groups, each group containing 3 mice: groupⅠ as control with 1.5 ?g pcDNA3.1; group Ⅱ with 1.5 ?g pcDNA3.1 G1; group Ⅲ with 1.5 ?g pcDNA3.1 G2.Each mouse was immunized two times. 4 weeks after primary vaccination, 1 boost was given. Results 1. In mice given intramuscular inoculation, serum anti hantavirus antibodies were detected 3 of 5 in group Ⅱ, 2 of 5 in group Ⅲ.IFA titers 1∶20～1∶80. NAb were detected 1 of 5 in group Ⅱ, 2 of 5 in group Ⅲ. NAb titers 1∶10～1∶20. 2.In mice given gene gun inoculation, serum anti hantavirus antibodies and NAb were detected in all experimental group mice, IFA titers 1∶20～1∶320, NAb titers≥1∶10. Conclusions Genetic immunization with HV Z37envelope glycoprotein genes G1 and G2 recombinants could elicit effective humoral immune response in mice.

Cloning of two different IL-15 genes and their effect on the humoral immune response elicited by HBV vaccine / 中国免疫学杂志

Objective:To study the effect of IL-15 eukaryotic expression plasmid on the humoral immune responses to HBV surface antigen protein vaccine.Methods:Had constructed two of IL-15 eukaryotic expression plasmides.One is the eukaryotic expression plasmid of the IL-15 whole sequence,the other is the chimeric eukaryotic expression plasmid of the IL-2 signal peptide and IL-15 mature peptide sequence(IL-2s-15).The bioactivities of the expression products of the two plasmids were identified by CTLL-2 proliferation assay.Results:After IL-15 plasmid co-immunized with HBsAg,the titer of anti-HBsIgG was much higher than that of control( P 0.05),however,the anti-HBsIgG2a/IgG1 ratio was higher than that of control.Conclusion:IL-15 expression plasmids effect differently on the immune responses induced by protein vaccine.

Immunization with the receptor-binding domain of SARS-CoV-2 elicits antibodies cross-neutralizing SARS-CoV-2 and SARS-CoV without antibody-dependent enhancement

Recently emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogen responsible for the ongoing coronavirus disease 2019 (COVID-19) pandemic. Currently, there is no vaccine available for preventing SARS-CoV-2 infection. Like closely related severe acute respiratory syndrome coronavirus (SARS-CoV), SARS-CoV-2 also uses its receptor-binding domain (RBD) on the spike (S) protein to engage the host receptor, human angiotensin-converting enzyme 2 (ACE2), facilitating subsequent viral entry. Here we report the immunogenicity and vaccine potential of SARS-CoV-2 RBD (SARS2-RBD)-based recombinant proteins. Immunization with SARS2-RBD recombinant proteins potently induced a multi-functional antibody response in mice. The resulting antisera could efficiently block the interaction between SARS2-RBD and ACE2, inhibit S-mediated cell-cell fusion, and neutralize both SARS-CoV-2 pseudovirus entry and authentic SARS-CoV-2 infection. In addition, the anti-RBD sera also exhibited cross binding, ACE2-blockade, and neutralization effects towards SARS-CoV. More importantly, we found that the anti-RBD sera did not promote antibody-dependent enhancement of either SARS-CoV-2 pseudovirus entry or authentic virus infection of Fc receptor-bearing cells. These findings provide a solid foundation for developing RBD-based subunit vaccines for SARS-CoV2.

Potent antiviral effect of protoporphyrin IX and verteporfin on SARS-CoV-2 infection

The SARS-CoV-2 infection is spreading rapidly worldwide. Efficacious antiviral therapeutics against SARS-CoV-2 is urgently needed. Here, we discovered that protoporphyrin IX (PpIX) and verteporfin, two FDA-approved drugs, completely inhibited the cytopathic effect produced by SARS-CoV-2 infection at 1.25 M and 0.31 M respectively, and their EC50 values of reduction of viral RNA were at nanomolar concentrations. The selectivity indices of PpIX and verteporfin were 952.74 and 368.93, respectively, suggesting broad margin of safety. Importantly, PpIX and verteporfin prevented SARS-CoV-2 infection in mice adenovirally transduced with human ACE2. The compounds, sharing a porphyrin ring structure, were shown to bind viral receptor ACE2 and interfere with the interaction between ACE2 and the receptor-binding domain of viral S protein. Our study suggests that PpIX and verteporfin are potent antiviral agents against SARS-CoV-2 infection and sheds new light on developing novel chemoprophylaxis and chemotherapy against SARS-CoV-2.

Stability of the COVID-19 virus under wet, dry and acidic conditions

COVID-19 has become a pandemic and is spreading fast worldwide. The COVID-19 virus is transmitted mainly through respiratory droplets and close contact. However, the fecal-oral transmission of the virus has not been ruled out and it is important to ascertain how acidic condition in the stomach affects the infectivity of the virus. Besides, it is unclear how stable the COVID-19 virus is under dry and wet conditions. In the present study, we have shown that the COVID-19 virus is extremely infectious as manifested by the infection of Vero-E6 cells by one PFU (Plaque Forming Unit) of the virus. We then investigated the stability of the COVID-19 virus in wet, dry and acidic (pH2.2) environments at room temperature. Results showed that the COVID-19 virus could survive for three days in wet and dry environments, but the dry condition is less favorable for the survival of the virus. Our study also demonstrated that the COVID-19 virus at a relative high titer (1.2 x 103 PFU) exhibits a certain degree of tolerance to acidic environment at least for 60 minutes. When the virus titer was [≤]1.0 x 103 PFU, acid treatment (pH2.2) for 30 or 60 minute resulted in virus inactivation. It suggests that the virus at a high concentration may survive in the acidic environment of the stomach. The finding of the present study will contribute to the control of the spread of the COVID-19 virus.