Whole genomic features analysis of coxsackievirus B3 strains isolated in Tianjin / 中国热带医学

@#Abstract: Objective　To genotype and analyze whole genomic features of Coxsackievirus B3 (CVB3) isolated in Tianjin, to improve evolution information of CVB3 virus in Tianjin, and to provide basis for surveillance and early warning of related diseases. Methods　Viral RNA was extracted from five CVB3 strains isolated in Tianjin, whole genome sequence of the virus was amplified by RT-PCR and sequenced by next-generation sequencing method, and phylogenetic and recombinant analysis were carried out. Results　The open reading frame 1(ORF) of the five CVB3 strains contained 6 555 nucleotides and encoded 2 185 amino acids, and ORF2 was composed of sequences encoding 68 amino acids. The nucleotide sequence similarity ranged from 78.3%-100%, and the amino acid sequence similarity ranged from 95.7%-100%. Compared with the CVB3 prototype strain, the nucleotide sequence similarity of the five viruses was between 78.2%-79.1%, and the similarity of amino acid sequences was 94.9%-95.3%. All five viruses exhibited a T151A mutation on the VP2 protein. Additionally, the encephalitis isolate showed a K158E mutation on the VP2 protein, while one of the sewage isolates had a C234T mutation in 5' noncoding region. The five strains belonged to two different genotypes, among which the encephalitis isolate in 2016 belonged to the D genotype, while the sewage isolates in 2021 belonged to the E genotype. This is also the first report of E genotype CVB3 in northern China. The CVB3 strain may have recombinant events in non-structural protein regions, in which encephalitis isolate may recombine with a Coxsackievirus B5 (CVB5) strain, while sewage isolates may have recombinant events with a strain of ECHO virus 18 (E18). Conclusions　The CVB3 isolates in Tianjin belong to D and E genotypes, and recombination events may exist in non-structural protein region of the viral genome. The results of CVB3 virus genome analysis in sewage suggests presence of CVB3 infection in the population of Tianjin, and its epidemic dominant genotype may have changed.

Two new ursane triterpenoids from Agastache rugosa (Fisch. et.Mey.) O. Kuntze / 药学学报

Two new ursane triterpenoids along with twelve known compounds were isolated from 80% ethanol extract of Agastache rugosa (Fisch. et. Mey.) O. Kuntze by using silica gel column, MCI column, ODS column and HPLC. The structures of the new compounds were identified as 2α,3α-dihydroxy-24-nor-urs-4(23),12(13)-dien-28-oic acid (1) and 2α,3α-dihydroxy-24-nor-urs-4(23),12(13),20(30) -trien-28-oic acid (2) by HR-ESI-MS, NMR and ECD spectral data, named agasursacid A and agasursacid B. In addition, compounds 3, 4, 6, 8 showed anti-coxsackievirus B3 (CVB3) activities with a IC50 as 4.77, 1.59, 11.11 and 25.87 μmol·L-1, resepectively.

Molecular identification of non-polio enteroviruses in acute flaccid paralysis cases in Henan Province of China in 2021 / 中华微生物学和免疫学杂志

Objective:To investigate the serotypes and epidemic characteristics of non-polio enteroviruses (NPEV) in acute flaccid paralysis (AFP) cases in Henan Province in 2021.Methods:Fecal specimens of 529 AFP cases reported in Henan Province in 2021 were collected for virus isolation. The VP1 regions of NPEV were sequenced. MEGA5.1 software was used for sequence alignment and a phylogenetic tree was constructed as well. The epidemiological data were organized and statistically analyzed using Excel2016 and SPSS26 software.Results:A total of 30 strains of NPEV were isolated from the fecal specimens of 529 AFP cases, with an isolation rate of 5.67% (30/529). They were belonged to group A and group B with 15 strains in each group, and no group C or group D viruses were isolated. Group A contained six serotypes and was dominated by coxsackievirus A2 (CVA2) and CVA6. Group B contained tree serotypes and was dominated by CVB3. In the population distribution, the separation rate of NPEV was the highest among children under 5 years old, which was 76.67% (23/30), and the ratio of male to female was 1.51∶1. In the regional distribution, group A viruses were mainly distributed in the central, southern and southwestern parts of Henan Province with CVA2 and CVA4 being the most widely distributed, while group B viruses were relatively concentrated, mainly distributed in the central, northern and southwestern parts of Henan Province with CVB3 being the predominant. In terms of time distribution, NPEV could be isolated throughout the year except from January to February, showing the epidemic characteristics of high incidence in spring and summer and low incidence in autumn and winter. The peak of group A virus infection was in May and the peak period of group B virus infection was from June to July.Conclusions:CVB3 was the main serotype of NPEV isolated in Henan Province in 2021. The pathogenic spectrum and regional distribution of NPEV had changed significantly compared with those in 2018-2019. In order to provide reference for the diagnosis and surveillance of AFP and maintain the polio-free status in Henan Province, much attention should be paid to the current epidemic trend of NPEV.

Protective effect of puerarin on viral myocarditis and the underlying mechanism / 国际儿科学杂志

Objective To detect the expression of Nrf2 in mice with viral myocarditis and to investigate the changes and effects of Nrf2 after puerarin (Pue) treatment.Methods A total of 130 BALB/C male mice aged 4 weeks were randomly divided into control group,VMC group,Nrf2 activator group and Pue group (20 mice in each group) with different concentrations.The models were made with Coxsackie B3 virus (CVB3).The mice were sacrificed on day 0,4,7,14 and 28 respectively,and blood and myocardial samples were harvested.Cardiomyocyte apoptosis was detected by flow cytometry.The expression changes of Nrf2,HO-1,Fas,TGF-beta 1 mRNA were detected by real-time PCR and Western blot respectively.Statistical software SPSS19.0 was used to analyze the results.The measurement data was expressed mean ± standard deviation.The paired samples were tested with mean t test.The group data were analyzed with two-way ANOVA.A P value of less than 0.05 was considered to indicate statistical significance.Correlation analysis was performed with Spearman's correlation test.Results Nrf2 mRNA and Nrf2 protein were expressed in all groups.The correlations between Nrf2 and HO-1,Fas and TGF-beta-1 were analyzed according to CPDT or Pue,and the results were consistent with each other.It showed that the relationship between Nrf2 and HO-1,Fas and TGF-beta-1 did not change with intervention measures.The transcription and protein expression of HO1 in CPDT and Pue groups were significantly increased,and were positively correlated with Nrf2 (r =0.969,P ＜0.01).At a certain dose gradient (＜ 45 mg/kg),the transcription and protein expression of HO-1 were dose-dependent;the decreased cardiomyocyte apoptosis was observed in both CPDT and Pue group,while Nrf2 and Fas were negatively correlated (r =-0.968,P ＜ 0.01);at a certain dose gradient,the expression of TGF-beta 1 in CPDT and Pue group decreased with the increase of dose,and Nrf2 and TGF-beta 1 were negatively correlated (r =-0.753,P ＜ 0.01).Conclusion The increased expression of Nrf2 in VMC is involved in the occurrence and development of VMC.Nrf2 has antioxidant effect in VMC by up-regulating the antioxidant enzyme HO-1,has the anti-myocardial APO effect by inhibiting the Fas/FasL signaling pathway,and inhibits myocardial fibrosis by suppressing the expression of TGF-beta 1 protein and transcription.The therapeutic effect of Pue on VMC is to activate Nrf2 to produce antioxidant,anti-apoptotic and anti-fibrotic effects.

Coxsackievirus B3 Infection Triggers Autophagy through 3 Pathways of Endoplasmic Reticulum Stress / 生物医学与环境科学（英文）

OBJECTIVE@#Autophagy is a highly conserved intracellular degradation pathway. Many picornaviruses induce autophagy to benefit viral replication, but an understanding of how autophagy occurs remains incomplete. In this study, we explored whether coxsackievirus B3 (CVB3) infection induced autophagy through endoplasmic reticulum (ER) stress.@*METHODS@#In CVB3-infected HeLa cells, the specific molecules of ER stress and autophagy were detected using Western blotting, reverse transcription polymerase chain reaction (RT-PCR), and confocal microscopy. Then PKR-like ER protein kinase (PERK) inhibitor, inositol-requiring protein-1 (IRE1) inhibitor, or activating transcription factor-6 (ATF6) inhibitor worked on CVB3-infected cells, their effect on autophagy was assessed by Western blotting for detecting microtubule-associated protein light chain 3 (LC3).@*RESULTS@#CVB3 infection induced ER stress, and ER stress sensors PERK/eIF2α, IRE1/XBP1, and ATF6 were activated. CVB3 infection increased the accumulation of green fluorescent protein (GFP)-LC3 punctuation and induced the conversion from LC3-I to phosphatidylethanolamine-conjugated LC3-1 (LC3-II). CVB3 infection still decreased the expression of mammalian target of rapamycin (mTOR) and p-mTOR. Inhibition of PERK, IRE1, or ATF6 significantly decreased the ratio of LC3-II to LC3-I in CVB3-infected HeLa cells.@*CONCLUSION@#CVB3 infection induced autophagy through ER stress in HeLa cells, and PERK, IRE1, and ATF6a pathways participated in the regulation of autophagy. Our data suggested that ER stress may inhibit mTOR signaling pathway to induce autophagy during CVB3 infection.

Cinnamaldehyde Derivatives Inhibit Coxsackievirus B3-Induced Viral Myocarditis

The chemical property of cinnamaldehyde is unstable in vivo, although early experiments have shown its obvious therapeutic effects on viral myocarditis (VMC). To overcome this problem, we used cinnamaldehyde as a leading compound to synthesize derivatives. Five derivatives of cinnamaldehyde were synthesized: 4-methylcinnamaldehyde (1), 4-chlorocinnamaldehyde (2), 4-methoxycinnamaldehyde (3), α-bromo-4-methylcinnamaldehyde (4), and α-bromo-4-chlorocinnamaldehyde (5). Neonatal rat cardiomyocytes and HeLa cells infected by coxsackievirus B3 (CVB3) were used to evaluate their antiviral and cytotoxic effects. In vivo BALB/c mice were infected with CVB3 for establishing VMC models. Among the derivatives, compound 4 and 5 inhibited the CVB3 in HeLa cells with the half-maximal inhibitory concentrations values of 11.38 ± 2.22 μM and 2.12 ± 0.37 μM, respectively. The 50% toxic concentrations of compound 4 and 5-treated cells were 39-fold and 87-fold higher than in the cinnamaldehyde group. Compound 4 and 5 effectively reduced the viral titers and cardiac pathological changes in a dose-dependent manner. In addition, compound 4 and 5 significantly inhibited the secretion, mRNA and protein expressions of inflammatory cytokines TNF-α, IL-1β and IL-6 in CVB3-infected cardiomyocytes, indicating that brominated cinnamaldehyde not only improved the anti-vital activities for VMC, but also had potent anti-inflammatory effects in cardiomyocytes induced by CVB3.

Synthesis and biological evaluation of 12-N-benzenesulfonyl matrinic ether derivatives as anti-coxsackievirus B3 agents / 药学学报

12-N-m-Cyanobenzenesulfonyl matrinic butyl methyl ether is a potent anti-coxsackievirus B3(CVB3) agent bearing a novel structure skeleton. Taking this compound as a lead, totally 15 novel target compounds have been synthesized and evaluated for the anti-CVB3 activities using CPE method. Structureactivity relationship (SAR) demonstrated that the shorten-length of 11-side chain was not helpful for keeping the good anti-virus activity. Among the newly synthesized compounds, compound c1 displayed a good anti-CVB3 activity with the IC50 of 7.1 μmol·L-1 and SI of 35.5, similar to that of the lead. The SAR results provided useful information for further optimization of these compounds in the molecular structure.

Antiviral and myocyte protective effects of IL-28A in coxsackievirus B3-induced myocarditis

Objective: This study aimed to investigate whether interleukin-28A (IL-28A) plays a role in murine myocarditis induced by coxsackievirus B3 (CVB3), and to explore its possible mechanism involved. Methods: Male BALB/c mice both infected and not infected by CVB3 were randomly divided into four groups (n = 40), untreated or treated with different doses of IL-28A for 4 days, and then sacrificed on days 4 and 7 post-infection. The heart samples were collected for histopathologic examination. Cardiac viral load was determined by a plaque assay. Additionally, immunoblot analysis, TUNEL assay, and immunohistochemistry were performed to examine the expression of signal transducer, activator of transcription 1 and 2 (STAT1 and STAT2), CVB3-induced apoptosis and the expression of Bcl-2, BAX and Caspase-3. Results: Compared to uninfected mice, the CVB3 infected mice exhibited higher mortality rate (p < 0.001), apparent inflammation and myocardial lesion (p < 0.01), and higher cardiac viral load (p < 0.01). After CVB3 infection, IL-28A treated mice presented no death (p < 0.001), reduced inflammation and myocardial lesion (p < 0.01), and lower viral load (p < 0.01) compared to untreated mice. Besides, treatment with IL-28A markedly increased the expressions of STAT1 and STAT2, and inhibited CVB3-induced apoptosis in myocardial cells with increased ratio of Bcl-2/BAX. Conclusion: The antiviral and myocyte protective effects of IL-28A in CVB3-inducedmyocarditis are regulated by STAT1 and STAT2. .

Antiviral Activity of Chrysin Derivatives against Coxsackievirus B3 in vitro and in vivo

Chrysin is a 5,7-dihydroxyflavone and was recently shown to potently inhibit enterovirus 71 (EV71) by suppressing viral 3C protease (3Cpro) activity. In the current study, we investigated whether chrysin also shows antiviral activity against coxsackievirus B3 (CVB3), which belongs to the same genus (Enterovirus) as EV71, and assessed its ability to prevent the resulting acute pancreatitis and myocarditis. We found that chrysin showed antiviral activity against CVB3 at 10 muM, but exhibited mild cellular cytotoxicity at 50 muM, prompting us to synthesize derivatives of chrysin to increase the antiviral activity and reduce its cytotoxicity. Among four 4-substituted benzyl derivatives derived from C(5) benzyl-protected derivatives 7, 9-11 had significant antiviral activity and showed the most potent activity against CVB3 with low cytotoxicity in Vero cells. Intraperitoneal injection of CVB3 in BALB/c mice with 1x106 TCID50 (50% tissue culture infective dose) of CVB3 induced acute pancreatitis with ablation of acinar cells and increased serum CXCL1 levels, whereas the daily administration of 9 for 5 days significantly alleviated the pancreatic inflammation and reduced the elevation in serum CXCL1 levels. Collectively, we assessed the anti-CVB3 activities of chrysin and its derivatives, and found that among 4-substituted benzyl derivatives, 9 exhibited the highest activity against CVB3 in vivo, and protected mice from CVB3-induced pancreatic damage, simultaneously lowering serum CXCL1 levels.

Effect of Ginsenoside Re and Rb3 on mice with viral myocarditis / 中国小儿急救医学

Objective To study the role of Ginsenoside Re and Rb3 on mice with viral myocarditis (VMC) and explore the mechanisms. Methods BALB/C mice were infected by coxsackievirus B3 ( CVB3) to establish VMC model. The mice were divided into control group,virus group and Ginsenoside Re and Rb3 treatment group(treatment group). On day 5,day 10,day 20 after infection,the level of serum crea-tine phosphokinase-MB( CK-MB) was detected. Then myocardial sections stained with Masson′s trichrome were used to observe the distribution of mice myocardial collagen fibers, quantify collagen volume fraction (CVF),and detect the levels of superoxide dismutase(SOD). Results (1)The level of CK-MB peaked on day 5,and decreased afterwards[day 5:(463. 68 ± 47. 62) U/L; day 10:(588. 81 ± 56. 09) U/L; day 20:(340. 48 ± 58. 22) U/L,respectively]. While the levels of CK-MB in treatment group were lower than those in virus group[day 5:(378. 69 ± 56. 02) U/L;day 10:(452. 56 ± 67. 78) U/L; day 20:(327. 13 ± 47. 20) U/L,respectively] in the same point. There were significant differences between groups on day 5 and day 10 (P<0. 01). (2) In viral group,the blue staining degree gradually increased with time in myocardial sections stained with Masson′s trichrome,especially in myocardial necrosis area. Compared with treatment group,CVF increased significantly in virus group on day 10 and day 20 ( day 10:6. 52% ± 2. 34% vs. 8. 94% ± 1. 67%;day 20:7. 00% ± 1. 53% vs. 10. 46% ± 1. 74%,P<0. 01). The levels of SOD in myocardial sections in virus group were lower than those of control group[day 5:(48. 83 ± 17. 74) U/L;day 10:(61. 41 ± 14. 58) U/L;day 20:(66. 26 ± 18. 97) U/L,respectively,P<0. 05],but in treatment group,the level of SOD could beimprovedsignificantly[day5:(72. 07 ±24. 85)U/L;day10:(83. 22 ±19. 52)U/L;day20:(92. 00 ± 20. 46) U/L, respectively, P < 0. 05]. Conclusion Because of the inhibition of oxygen radicals and oxidative stress, Ginsenoside Re and Rb3 can protect myocardial tissue. Ginsenoside Re and Rb3 can effectively reduce the extent of myocardial fibrosis. The mechanism may be related with the reduced peroxide level in vivo.

Genomic characteristics of a coxsackievirus B3 strain KM06/2009 isolated in Kunming,Yunnan,Chi-na / 中华微生物学和免疫学杂志

Objective To analyze the complete genome sequence of a coxsackievirus B 3 (CVB3) strain KM06/2009 and its genetic variation , evolution and cardiovirulence .Methods Eight clones with overlapped gene fragments covering the complete viral genome ( excluding the poly-A tail) were obtained by RT-PCR and sequenced .The nucleotide ( nt ) and amino acid ( aa ) sequences of the eight clones were aligned with sequences of other known CVB 3 clinical strains .Phylogenetic and pairwise alignment analyses based on the genome and complete VP 1 regions were conducted by using Mega 4.1,RDP3 and SimPlot3.5.1 softwares.The RNA secondary structure of CVB3 stem loopⅡ (SLⅡ) was determined by using Mfold web server.Results The complete genome of CVB3 strain KM06/2009 was 7401 nt in length, consisting of 743 nt and 100 nt on 5′untranslated region (UTR) and 3′UTR,respectively.The entire open reading frame contained 6558 nt, encoding a 2185 aa polyprotein.There was no nucleotide deletion or insertion in the coding region,but some changes of amino acid were unique .KM06/2009 strain showed 81.4%and 95.7%identities in nucleotide and amino acid sequences respectively as compared with CVB 3 prototype Nancy strain.It shared 88.4%-98.1%nucleotide and 98.1%-99.4%amino acid homology with the other Chinese clinical strains isolated at the same period .KM06/2009 strain and CVB3 GA strain without cardiovirulence shared 80.7%homology in nucleotide and 96.4% in amino acid.The phylogenetic analysis indicated that the significant spatial and temporal clustering was detected in CVB 3 isolate.CVB3 KM06/2009 strain showed a strong cardiovirulence tendency as indicated by the RNA secondary structure of CVB 3 SL Ⅱ. Conclusion CVB3 KM06/2009 isolate showed a strong cardiovirulence tendency in comparison with other CVB3 clinical isolates based on the bioinformatics analysis .

Expression and significance of myocardial interleukin-17A in mice with viral myocarditis / 中华实用儿科临床杂志

Objective To explore the expression of interleukin-17A(IL-17A) in the myocardium of mice with experimental viral myocarditis (VM) and its clinical significance.Methods Fifty-five mice were randomly divided into myocarditis group(n =45) and control group(n =10).Mice in the myocarditis group were inoculated intraperitoneally with 0.1 mL Eagle's solution containing coxsackievirus B3 (CVB3) to establish VM models.However,mice in the control mice were treated with 0.1 mL Eagle's solution.Ten infected mice were sacrificed on day 7,14 and 28 after inoculation,and the control mice were killed on day 28 postinoculation.Myocardial histopathology was determined with hematoxylin and eosin stain.The levels of myocardial IL-17A mRNA and protein expressions were detected by real time quantitative polymerase chain reaction(RQ-PCR) and immunohistochemistry.Serum IL-17A concentration was examined using enzyme linked immunosorbent assay(ELISA).In addition,the relationship between myocardial IL-17A protein levels as well as serum IL-17A concentration and myocardial histopathological scores were analyzed statistically in myocarditis group.Results The levels of myocardial IL-17A mRNA and protein and serum IL-17A concentration on day 7 and 14 after inoculation in myocarditis group increased significantly compared with those in control group(all P ＜ 0.01).Myocardial IL-17A protein levels and serum IL-17A concentration showed significantly positive correlation with the myocardial histopathologic scores in VM group,respectively (r =0.67,0.74,all P ＜ 0.05).Conclusions IL-17A may play a pivotal role in the pathogenesis of VM and is associated with the severity of VM.It can serve as a novel indicator for VM.

Expression of osteopontin and collagen type Ⅰ in rat myocardial fibroblasts infected by coxsackievirus B3 / 中国综合临床

Objective To study the expression of osteopontin (OPN) and collagen type Ⅰ in the rat myocardial fibroblasts infected by coxsackievirus B3 (CVB3) and to explore the possible pathogenesis of OPN on viral myocarditis.Methods Cardiac fibroblasts were isolated from neonatal rat and cultured with an traditional method.The primary cultured rat myocardial fibroblasts were infected by CVB3 which multiplicity of infection (MOI) was 0.5 PFU/cell.The myocardial fibroblasts were divided into control group 12 h and CVB3 groups (infected after 12 h,1 d,2 d,3 d).The expression of OPN and collagen type Ⅰ were detected by RT-PCR,Western Blotting and immunohistochemistry.And the linear correlation between the expression of OPN and the expression of collagen type Ⅰ was analyzed.Results ( 1 ) The gray scale values of the OPN/β-actin in control group(12 h)and viral groups (12 h,1 d,2 d,3 d) were 0.38 ± 0.06,0.56 ± 0.06,0.72 ± 0.05,0.98 ± 0.06,0.86 ± 0.02 respectively with RT-PCR,and were 0.26 ± 0.03,0.36 ± 0.03,0.52 ± 0.04,0.76 ± 0.05,0.62 ± 0.02 respectively with Western Blotting.The expression of OPN was found to be increased after 12 h infection,reached to the maximum after 2 d infection and displayed a decreased tendency after 3 d infection.There was significant difference on the gray scale values of the OPN/β3-actin ( F=74.965,53.004,respectively,P ＜ 0.05 ).(2) The gray scale values of the collagen type Ⅰ/β-actin in control group (12 h)and viral groups (12 h,1 d,2d,3 d) were 1.12 ± 0.03,1.18 ± 0.01,1.22 ± 0.02,1.33 ± 0.02,1.28 ± 0.03,respectively with RTPCR.These results suggested that the collagen type Ⅰ expression started to increase at 12 h when infected by CVB3,reached to the maximum at 2 d,and then decreased after 3 d infection,the difference was significant ( F =38.241,P ＜ 0.05).(3) The expression of OPN was positively correlated with the expression of collagen type Ⅰ ( r=0.948,P ＜ 0.001 ).Conclusion CVB3 can induce the expression of OPN and collagen type Ⅰ in the rat myocardial fibroblasts and the expression of OPN and collagen type Ⅰ displays positive correlation.It suggests that OPN can promote the expression of collagen type Ⅰ in myocardial fibroblasts,and may play an important role in the pathogenesis of viral myocarditis.

Development of a Gene Therapy Method for Cervical Cancer Using Attenuated Coxsackievirus B3 as a Vector System

We previously reported the development of an attenuated coxsackievirus B3, known as YYFF, which functioned as a viral vector system for foreign gene expression. In this study, we demonstrated the potential use of YYFF as a gene therapy vector. Recombinant YYFF was constructed to express the human papillomavirus 16 (HPV16) E7 gene, referred to as YYFF-HPV16-E7. Growth of YYFF-HPV16-E7 resembled the wild type, YYFF, and it expressed HPV16-E7 in cell culture. When YYFF-HPV16-E7 was directly injected into TC-1-transplanted C57/BL6 mice, there was no reduction in tumor size, because of the non-growth of YYFF in C57/BL6 mice. However, when YYFF-HPV16-E7-induced immune cells/serum that originated from BALB/c mice was passively delivered into BALB/c background TC-1-transplanted nude mice, it reduced the size of cervical tumors in the nude mice. This study indicates the potential use of YYFF-HPV16-E7 as a gene therapy agent for treating HPV-induced cervical cancer.

Effects of atorvastatin on the improvement of heart function in mice with viral myocarditis / 中华急诊医学杂志

Objective To investigate the effects of atorvastatin on the improvement of cardiac function of mice with myocarditis.Methods A total of 146 Balb/c mice were divided into four groups randomly(random number).The viral myocarditis(VMC)model was made by Coxsakie virus B3(CVB)injected intra-abdominally.Four groups were normal group(n =18),VMC group(n =60),Control group (n=18)and VMCtreatment group(n =50).The mice of control group were treated with atorvastatin without VMC,and the mice of VMC treatment group were with VMC and were given atorvastatin for 2 weeks.Echocardiograms were used 3,7,10,14,21,and 30 days after virus inoculation.Blood samples were collected for cardiac troponin-Ⅰ detection at the same time.Myocardial inflammation was examined by using histochemistry staining.The changes of myocardial collagen fiber,myocardial cells and various organelles were examined by electron microscope.Results Compared with VMC group,the cumulative survival rate of VMC group treatment group was higher(87.0％ vs 59.2％)after treatment with atorvastatin for 30 days (P =0.008),and the improvement of pathological features after treatment with atorvastatin was found 10,14,21 and 30 days after the inoculation.Compared with control group,the cardiac function was decreased in the CVB infected mice 7 days after virus challenge[(69.82 ±5.12)vs(89.23 ±2.01),P ＜0.01]and compared with VMC group,the EF values of VMC treatment group were significantly higher 7,14,21and 30 days after virus inoculation.The differences in cTnI values between VMC group and CVB treatment group were statistically significant 7,10,14 and 21 days after virus challenge.Conclusions These results demonstrate that atorvastatin improves survival rates and the histological features in CVB3m-induced myocarditis.It can improve the heart function of CVB infected mice.Atorvastatin could be a treatment of choice for VMC.

Comparison of the immune effects of Coxsackievirus B3 VP1 protein, rAd/VP1 and pcDNA3/VP1 in mice / 中华微生物学和免疫学杂志

Objective To compare the immune effects of Coxsackievirus B3 (CVB3) capsid protein VP1 expressed bacterially, recombinant adenovirus rAd/VP1 and recombinant plasmid pcDNA3/VP1which express VP1 protein in mice. Methods After expressed in prokaryotic cells, VP1 protein was purified. Recombinant adenovirus rAd/VP1 and recombinant plasmid pcDNA3/VP1 were amplified and extracted. Six to 8-week-old, male BALB/c mice were divided into four groups randomly. Each group contained 18 mice. The mice of pcDNA3/VP1 group or VP1 protein group were immunized intramuscularly with three injections at three weeks apart, of recombinant plasmid pcDNA3/VP1 at a dose of 100 μg/mouse or recombinant protein VP1 at a dose of 50 μg/mouse. The mice of rAd/VP1 group were immunized intramuscularly twice at two weeks interval with rAd/VP1 at a dose of 1.2 × 107 PFU. The control group was mock-immunized with 100 μl of PBS intramuscularly. Mice were bled from the retroorbital sinus plexus every two weeks after each immunization. ELISA and micro-neutralization test were used to detect levels of CVB3-specific IgG antibody and neutralizing antibody titers in the sera of immunized mice. Three weeks after the last immunization, the cytotoxic T lymphocyte(CTL) killing activity of spleen lymphocytes was detected with CCK-8 assay. Subsequently, virus titers in the sera of immunized mice were determined by the 50% cell culture infective dose( CCID50 ) assay on HeLa cell monolayers and percentage of animals surviving were observed after lethal CVB3 attack over a period of 21 days. Results The titers of specific IgG antibody and neutralizing antibody in sera of VP1 protein immunized mice were higher than other groups( P ＜0.05 ). While CTL killing activity of spleen lymphocytes of VP1 protein immunized mice was lower than mice in rAd/VP1 group( P ＜0. 05). Virus titers in sera of VP1 protein immunized mice were lower than the mice in pcDNA3/VP1 or rAd/VP1 groups ( P ＜ 0.05 ), while survival rate was significantly higher than these two groups ( P ＜ 0.05 ).Conclusion VP1 protein induced higher level of humoral immune response and acquired obvious immune protection effects in mice. The immunizing potency of VP1 protein vaccine surpassed plasmid pcDNA3/VP1or recombinant adenovirus rAd/VP1. It appeared to be a promising candidate among the three different vaccines.

The immunological effect of Ad/MDC-VP1 combined with DNA vaccine against Coxsackievirus infection / 中华微生物学和免疫学杂志

Objective To construct recombinant adenovirus Ad/MDC-VP1 and investigate its im-muno-boosting effect of the mice primed with the experimental DNA vaccine against Coxsackievirus infection. Methods The recombinant adenovirus Ad/MDC-VP1 was constructed and packaged. The Western blot analysis was used to verify the target protein. BALB/c mice were divided into four groups: Ad/MDC-VP1 group, pcDNA3/MDC-VP1 group, pcDNA3/MDC-VP1 prime-Ad/MDC-VP1 boost group and PBS group. The mice in each group were immunized intramuscularly. The titers of serum IgG and neutralizing antibody were tested by ELISA and trace neutralization assay, respectively. The lymphocytes proliferation activity and specific CTL cytotoxic activity were tested by CCK-8 assay. The mice in each group were challenged with le-thal dose of Coxsackievirus, and the assay of the serum virus titers and the observation of protection efficacy against Coxsackievirus infection were carried out. Results The recombinant adenovirus Ad/MDC-VP1 was successfully constructed and the target protein was expressed. It was observed that the titers of CVB3 VP1 specific antibody, lymphocyte stimulation index, CTL cytotoxicity activities and protection rate of the pcDNA3/MDC-VP1 prime-Ad/MDC-VP1 boost group were much higher than those of the rest groups( P < 0.05), and the titer of serum virus was lower after CVB3 challenged ( P < 0.05 ). Conclusion Both the cellular and humoral immune responses in mice could been significantly enhanced by the pcDNA3/MDC-VP1 prime-Ad/MDC-VP1 boost strategy.

Expression of Plus- and Minus-strand Viral RNA in Coxsackievirus B3-Infected A/J Mice

In order to investigate the implication of viral replication in acute, subacute, and chronic infections of coxsackievirus B3 (CVB3), we examined the histopathological changes and plus- and minus-strand viral RNA dynamics in heart, pancreas, brain, and liver of CVB3-infected A/J mice. Mice were inoculated intraperitoneally with CVB3 and sacrificed on 1, 2, 3, 4, 7, 10, 14, 21, 30, 60, and 90 days post infection (p.i.). Plus- and minus-strand viral RNAs in the organs were quantitated and the organs were additionally evaluated histopathologically for inflammation. No inflammatory infiltrates were observed in the liver, brain, and heart. In contrast, massive lymphocyte infiltration and fat replacement were shown in the pancreas with loss of acinar cells. Both plus- and minus-strand viral RNA levels were detected by 21 days p.i. in heart, 90 days p.i. in pancreas, 4 days p.i. in liver, and 10 days p.i. in brain. The plus-strand RNA was found at least fifty fold higher than the minus-strand RNA by 4 days p.i. in heart and pancreas and by 3 days p.i. in liver. The plus- to minus-strand RNA ratio in brain was found less than 1:20. Our data indicate that viral replication was actively occurred in heart, pancreas, and liver during acute CVB3 infection, whereas viral replication was limited in brain. Furthermore, chronic persistent viral RNA was observed in pancreas. In conclusion, CVB3 at low dose of virus induces severe pancreatitis but marginal or no inflammatory changes in the heart, liver, and brain.

Host Gene Profiling of Coxsackievirus B3 H3- and 10A1-infected Mouse Heart

Coxsackievirus B3 (CVB3) is a non-enveloped virus that has a single-stranded RNA genome. CVB3 induces myocarditis, and ultimately, dilated cardiomyopathy. A myocarditis variant of CVB3 (CVB3 H3) and its antibody-escape mutant (CVB3 10A1) were studied previously; H3 was found to induce myocarditis and 10A1 was found to be attenuated in infected mice. Although amino acid residue 165, located in a puff region of VP2, was found to be altered (i.e., the H3 asparagine was altered to aspartate in 10A1), the detailed mechanism of attenuation was not clearly elucidated. Here, DNA microarray technology was used to monitor changes in mRNA levels of infected mouse hearts after CVB3 H3 and 10A1 infection. This tool was used to elucidate the pathogenic mechanisms of viral infection by understanding virus-host interactions. We identified several genes, including protein tyrosine kinases, Ddr2 and Ptk2, as well as Clqb and Crry, involved in complement reactions, which may be involved in these viral processes. Thus, gene profiling can provide an opportunity to understand host immune responses to viral infection for gene therapy and may contribute to the identification of the target gene that is modified during treatment of viral myocarditis.

Development of Peptide Antibody against Coxsackievirus B3 VP2

Coxsackievirus B3 (CVB3) is the nonenveloped virus containing a single-stranded positive-sense RNA as a genome. CVB3 infection can induce acute myocarditis and dilated cardiomypathy. CVB3 of icosahedral symmetry has four capsid proteins called VP1, VP2, VP3, and VP4. Although VP1 is a major antigenic determinant, VP2 is also an important protein for viral physiology, such as maturation cleavage and attenuation. However, VP2 study has been hampered, partly because VP2 antibody is not available. In this study, we developed peptide-based polyclonal VP2 antibody and analyzed its potency by Western blotting analysis and immunofluorescent assay. Purified B3-1 antibody (VP2 peptide antibody developed in here) showed the sensitivity and specificity, similar to VP1 monoclonal antibody which is commercially available. Moreover, this peptide antibody may be useful for double-staining with other antibodies derived from mouse. Therefore, the VP2 antibody may allow us to study CVB assembly and understand VP2 function in depth.