Expression of Foot-and-Mouth Disease Virus Capsid Proteins in Silkworm-Baculovirus Expression System and Its Utilization as a Subunit Vaccine

Background: Foot-and-mouth disease (FMD) is a highly contagious disease of livestock that causes severe economic loss in susceptible cloven-hoofed animals. Although the traditional inactivated vaccine has been proved effective, it may lead to a new outbreak of FMD because of either incomplete inactivation of FMDV or the escape of live virus from vaccine production workshop. Thus, it is urgent to develop a novel FMDV vaccine that is safer, more effective and more economical than traditional vaccines. Methodology and Principal Findings: A recombinant silkworm baculovirus Bm-P12A3C which contained the intact P1-2A and 3C protease coding regions of FMDV Asia 1/HNK/CHA/05 was developed. Indirect immunofluorescence test and sandwich-ELISA were used to verify that Bm-P12A3C could express the target cassette. Expression products from silkworm were diluted to 30 folds and used as antigen to immunize cattle. Specific antibody was induced in all vaccinated animals. After challenge with virulent homologous virus, four of the five animals were completely protected, and clinical symptoms were alleviated and delayed in the remaining one. Furthermore, a PD50 (50 % bovine protective dose) test was performed to assess the bovine potency of the subunit vaccine. The result showed the subunit vaccine could achieve 6.34 PD50 per dose

Foot-and-mouth disease:overview of motives of disease spread and efficacy of available vaccines

Control and prevention of foot and mouth disease (FMD) by vaccination remains unsatisfactory in endemic countries. Indeed, consistent and new FMD epidemics in previously disease-free countries have precipitated the need for a worldwide control strategy. Outbreaks in vaccinated animals require that a new and safe vaccine be developed against foot and mouth virus (FMDV). FMDV can be eradicated worldwide based on previous scientific information about its spread using existing and modern control strategies

Wastewater surveillance of enteric viruses in eastern Argentina: High rates of detection and first report of NoV GI.5 and GII.20

Individuals infected with enteric viruses excrete them in their feces for an extended period, whether symptomatic or asymptomatic. This characteristic, combined with the capability of these viruses to persist in the environment, forms the core of our research. The objective of our study was to investigate the presence of viruses associated with diarrhea and hepatitis: Hepatitis A virus (HAV), Hepatitis E virus (HEV), Norovirus GI (NoV GI), Norovirus GII (NoV GII), and Rotavirus (RV) by RT-real time PCR, in untreated wastewater samples (n=100) collected in the period July 2020 to August 2021 from two low-income neighborhoods in the district of La Plata, Buenos Aires, Argentina. Globally, the percentage of positive samples was 25 % for HEV, 27 % for RV, 14 % for NoV GII, 1 % for NoV GI, and no detectable samples were found for HAV. HEV, RV, and NoV GII were detected in most of the studied months, with the highest detection rates of RV and NoV GII during the winter season. Regarding RV positive samples, the gene encoding the VP8* protein of three samples was sequenced and phylogenetic analysis revealed that the detected strains belonged to genotypes P[8] and P[3]. Additionally, four NoV strains were also genetically characterized by amplifying a fragment corresponding to the ORF-1/ORF-2 junction region. The identified strains were NoV GI.5, NoV GII.4, NoV GII.17 and NoV GII.20. Our results provide relevant information and serve as scientific evidence of the importance of considering wastewater analysis as a feasible strategy to determine the circulation of enteric viruses in the population, with the further benefit of predicting emerging strains. Moreover, this study represents the first report of the circulation of NoV GII.20 and GI.5 genotypes in our country

Stable production of peptide antigens in transgenic tobacco chloroplasts by fusion to the p53 tetramerisation domain

7 p., 3 figures and bibliographyThe production of short peptides as single molecules in recombinant systems is often limited by the low stability of the foreign peptide. In the plant expression system this problem has been solved by translational fusions to recombinant proteins that are highly stable or are able to form complex structures. Previously, we demonstrated that the highly immunogenic 21 amino acid peptide 2L21, which is derived from the canine parvovirus (CPV) VP2 protein, did not accumulate in transgenic tobacco chloroplasts. In this report, we translationally fused the 2L21 peptide to the 42 amino acid tetramerisation domain (TD) from the human transcription factor p53. The chimaeric 2L21-TD protein was expressed in tobacco chloroplasts. Leaves accumulated high levels of the recombinant protein (up to 0.4 mg/g fresh weight of leaf material, equivalent to ~6% of total soluble protein; 2% considering only the 2L21 peptide). The 2L21-TD protein was able to form tetramers in the stroma of the chloroplast. Mice immunised intraperitoneally with partially purified leaf extracts containing the 2L21-TD protein developed specific antibodies with titres similar to those elicited by a previously reported fusion between 2L21 and the B subunit of the cholera toxin. Mouse sera were able to detect both the 2L21 synthetic peptide and the CPV VP2 protein, showing that the antigenicity of the 2L21 epitope was preserved in the chimaeric protein. These results demonstrate that the p53 TD can be used as a carrier molecule for the accumulation of short peptides (such as 2L21) in the chloroplast without altering the immunogenic properties of the peptide.This work was partially supported by Grant BIO2005-00155 from the Ministerio de Educación y Ciencia (Spain).Peer reviewe