Inhibition of encephalomyocarditis virus replication by shRNA targeting 1D and 3AB genes in vitro and in vivo

Inhibition of encephalomyocarditis virus replication by shRNA targeting 1C and 2A genes in vitro and in vivo

Encephalomyocarditis virus (EMCV) infects many mammalian species, causing myocarditis, encephalitis and reproductive disorders. The small interference RNA (siRNA) targeting to the virus has not been understood completely. Here, two out of six interference sequences were screened to inhibit significantly EMCV replication by using recombinant plasmids expressing small hairpin RNA (shRNA) targeting to the viral 1C or 2A genes in BHK-21 cells. And two recombinant adenoviruses expressing the shRNAs were constructed and named as rAd-1C-1 and rAd-2A-3. They inhibit EMCV replication in BHK-21 cells in protein levels, as well as the virus yields by approximately 1000 times. Furthermore, they provide high protective efficacy against the challenge with virulent EMCV NJ08 strain in mice. And the EMCV loads in the live mice in rAd-1C-1 and rAd-2A-3 groups decrease by more than 90 % compared with those in the dead mice in the challenge control groups at the same times. It indicates that the adenoviruses medicated shRNA targeting to 1C and 2A genes might provide a potential strategy for combating EMCV infection.

Structure-dependent antiviral activity of catechol derivatives in pyroligneous acid against the encephalomycarditis virus

The pyrolysis product, wood vinegar (WV), from Japanese larch exhibited strong antiviral activity against the encephalomycarditis virus (EMCV). Catechol, 3-methyl-, 4-methyl-, 4-ethyl-, and 3-methoxycatechol, and 2-methyl-1,4-benzenediol were identified as the major antiviral compounds. The viral inhibition ability of these compounds was affected by the structure and position of the substituent group attached to the aromatic skeleton. The IC50 of catechol was 0.67 mg mL-1 and those of its derivatives were <0.40 mg mL-1. Methyl and ethyl substitution in the para position relative to a hydroxyl group obviously increased the antiviral activities. The mode of antiviral action was investigated by adding catechol derivatives at different times of the viral life cycle. It was found that direct inactivations of EMCV by these compounds were the major pathway for the antiviral activity. The effect of catechol derivatives on the host immune system was studied by quantification of Il6 and Ifnb1 expression levels. Increased Il6 expression levels indicate NF-κB activation by reactive oxygen species from auto-oxidations of catechol derivatives, which is also a possible antiviral route. The present research provides indices for production of potent antiviral agents form lignocellulose biomass.

Identification of VP1 peptides diagnostic of encephalomyocarditis virus from swine

Background

Encephalomyocarditis virus (EMCV) can cause myocarditis, respiratory failure, reproductive failure, and sudden death in pre-weaned piglets, which has been isolated in China. EMCV VP1 protein was one of the most important structural proteins and played an important role in the protective immunity. In this study, 10 monoclonal antibodies (McAbs) against EMCV VP1 were screened and identified.

Results

Epitope mapping results indicated that McAbs (6E11, 7A7, 7C9) specifically recognized the linear epitopes V(2)ENAEK(7), McAbs (1D1, 2A2, 5A1, 5A11, 5G1) recognized the epitope F(19)VAQPVY(25), and McAbs 1G8 and 3A9 recognized P(42)IGAFTVK(49). Protein sequence alignment of VP1 with 16 EMCV isolates indicated that the epitope F(19)VAQPVY(25) was conserved in all the reference strains. The epitopes P(42)IGAFTVK(49) and V(2)ENAEK(7) only had 1 or 2 variable amino acid among the reference strains. The 3D model analysis results showed that these epitopes presented as spheres were shown within the context of the complete particle.

Conclusions

In this study, ten McAbs against EMCV VP1 were developed and three B-cells epitopes (2-7aa, 19-25aa and 42-49aa) were defined in VP1. All the results herein will promote the future investigations into the function of VP1 of EMCV and development of diagnostic methods of EMCV.