Phenanthridine Derivative Host Heat Shock Cognate 70 Down-Regulators as Porcine Epidemic Diarrhea Virus Inhibitors.

Porcine epidemic diarrhea virus (PEDV) has become increasingly problematic around the world, not only for its hazards to livestock but also due to the possibility that it is a zoonotic disease. Although vaccine therapy has made some progress toward PEDV control, additional effective therapeutic strategies against PEDV are needed, such as the development of chemotherapeutic agents. The aim of this work was to identify novel anti-PEDV agents by designing and synthesizing a series of phenanthridine derivatives. Among them, three compounds (compounds 1, 2, and 4) were identified as potent anti-PEDV agents exhibiting suppression of host cell heat shock cognate 70 (Hsc70) expression. Mechanism studies revealed that host Hsc70 is involved in the replication of PEDV, and its expression can be suppressed by destabilization of the mRNA, resulting in inhibition of PEDV replication. Activity against PEDV in vivo in PEDV-infected piglets suggested that phenanthridine derivatives are the first host-acting potential anti-PEDV agents.

Development of an Aeromonas hydrophila recombinant extracellular protease vaccine.

Aeromonas hydrophila (Ah) exists widely in the aquatic environment and infects a variety of animals. Extracellular protease (EPR) is an important protective antigen that induces a specific antibody response to resist Ah infection. In this study, two genes encoding extracellular protease epr2 and epr3 were linked within the expression vector pET32a to construct a recombinant pET-epr2-3 plasmid. The immunogenicity of the fusion protein epr2-3 was investigated as a subunit vaccine in ICR mice. The recombinant epr2-3 protein induced the production of high antibody titers. The survival rate against homogenous Ah J-1 challenge was significantly higher in the epr2-3 vaccinated group (≥80%) compared with the inactivated Ah vaccinated group and the challenge control group (P < 0.01), thus indicating that the recombinant epr2-3 protein provided significant protection against Ah infection. Therefore, the recombinant epr2-3 is a promising candidate for development as a vaccine against Ah infections.

[Progress of research on microRNAs of parasites].

microRNAs (miRNAs) are small molecules of non-coding RNA, a class size of about 21-25 nt widespread in eukaryotes, resulting from single-stranded RNA precursors with the size of 70-90 bases of a hairpin structure generated after dicer enzyme processing. They play an important role in eukaryotic gene regulation, widely involved in cell proliferation, differentiation, development, metabolism, apoptosis and other physiological activities. miRNA extensively involved in the physiological and metabolic processes of the parasite development process, but the key miRNA relevant to parasite invasion of a host still lacks reports. This paper summarizes the miRNA analytical methods and the progress on its researches in parasitology.

[Construction of an infectious clone of pseudorabies virus strain ZJ genome maintained as a bacterial artificial chromosome].

pHA2 plasmid sequence,with Bacterial Artificial Chromosome(BAC) vector and the GFP expression cassette, was introduced into the UL23(TK) gene of Pseudorabies virus(PRV)strain ZJ by homologous recombination,and the recombinant PRV (rPRV-HA2) was confirmed and isolated by plaque purification. The circular genome of rPRV-HA2 was electroporated into Escherichia coli strain DH10B and then the PRV BAC (pPRV) was recovered. The transfection of pPRV into VeroE6 cells resulted in productive infection. The rescued virus isolated following transfection was indistinguishable from rPRV-HA2 in cytopathic effects (CPE) and replication curve in vitro. The growth kinetics of the viruses indicated that partial deletion of TK gene and BAC vector insertion had no effect on the viral titre and plaque size in vitro. The PRV BAC system will enable quick and reliable manipulation of the viral genome for the functional investigation on the PRV genes and the development of PRV vector in vaccine.