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Zhang X.,Jiangsu Academy of Agricultural Sciences | Zhang X.,Key Laboratory of Engineering Research of Veterinary Bio products | Zhang X.,National Center for Engineering Research of Veterinary Bio products | Zhang X.,Jiangsu Electric Power Company | And 9 more authors.
PLoS ONE | Year: 2014

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is the causative agent of hemorrhagic colitis and hemolytic uremic syndrome in humans. However, the bacterium can colonize the intestines of ruminants without causing clinical signs. EHEC O157:H7 needs flagella (H7) and hemorrhagic coli pili (HCP) to adhere to epithelial cells. Then the bacterium uses the translocated intimin receptor (Tir) and an outer membrane adhesion (Intimin) protein to colonize hosts. This leads to the attachment and effacement of (A/E) lesions. A tetravalent recombinant vaccine (H7-HCP-Tir-Intimin) composed of immunologically important portions of H7, HCP, Tir and Intimin proteins was constructed and its efficacy was evaluated using a caprine model. The results showed that the recombinant vaccine induced strong humoral and mucosal immune responses and protected the subjects from live challenges with EHEC O157:H7 86-24 stain. After a second immunization, the average IgG titer peaked at 7.2×10 5. Five days after challenge, E. coli O157:H7 was no longer detectable in the feces of vaccinated goats, but naïve goats shed the bacterium throughout the course of the challenge. Cultures of intestinal tissues showed that vaccination of goats with H7-HCP-Tir-Intimin reduced the amount of intestinal colonization by EHEC O157:H7 effectively. Recombinant H7-HCP-Tir-Intimin protein is an excellent vaccine candidate. Data from the present study warrant further efficacy studies aimed at reducing EHEC O157:H7 load on farms and the contamination of carcasses by this zoonotic pathogen. © 2014 Zhang et al. Source

Li W.,Jiangsu Academy of Agricultural Sciences | Li W.,Key Laboratory of Veterinary Biological Engineering and Technology | Li W.,National Center for Engineering Research of Veterinary Bio products | Mao L.,Jiangsu Academy of Agricultural Sciences | And 15 more authors.
Vaccine | Year: 2015

Classical swine fever (CSF) is a highly contagious and economically important viral disease that affects the pig industry worldwide. The glycoprotein E2 of CSFV can induce neutralizing antibodies and protective immunity, and is widely used for novel vaccine development. The objective of this study was to explore whether a tetraspanin molecule CD81 could improve the immune responses of an E2-based DNA vaccine. Plasmids pVAX-CD81, pVAX-E2 and pVAX-CD81-E2 were constructed and the expression of target proteins was confirmed in BHK-21 cells by indirect immunofluorescence assay. BALB/c mice were divided into 5 groups and immunized with different plasmids (pVAX-E2, pVAX-CD81-E2, pVAX-E2. +. pVAX-CD81, pVAX-CD81 and PBS) three times with two weeks interval. The results showed that the introduction of CD81 promoted higher humoral and cellular immune responses than E2 expression alone (. P<. 0.05). In addition, immunization with pVAX-CD81-E2 induced stronger immune responses than pVAX-E2. +. pVAX-CD81. Furthermore, four groups of pigs were immunized with pVAX-E2, pVAX-CD81-E2, pVAX-CD81 and PBS, respectively. Humoral and cellular immune responses detection showed similar results with those in mice. Compared to pVAX-E2, pVAX-CD81-E2 induced higher titers of neutralizing antibodies after viral challenge and conferred stronger protection. These results confirmed the capacity of swine CD81 enhancing the humoral and cellular responses with an adjuvant effect on CSFV DNA vaccine. This is the first report demonstrating the adjuvant effect of CD81 to enhance the DNA vaccination for swine pathogen. © 2015 Elsevier Ltd. Source

Du L.,Nanjing Agricultural University | Du L.,Jiangsu Academy of Agricultural Sciences | Du L.,Key Laboratory of Animal Diseases | Du L.,National Center for Engineering Research of Veterinary Bio products | And 11 more authors.
BioMed Research International | Year: 2013

Porcine reproductive and respiratory syndrome virus (PRRSV) has been mainly responsible for the catastrophic economic losses in pig industry worldwide. The commercial vaccines only provide a limited protection against PRRSV infection. Thus, the focus and direction is to develop safer and more effective vaccines in the research field of PRRS. The immune modulators are being considered to enhance the effectiveness of PRRSV vaccines. IFN-λ1 belongs to type III interferon, a new interferon family. IFN-λ1 is an important cytokine with multiple functions in innate and acquired immunity. In this study, porcine IFN-λ1 (PoIFN-λ1) was evaluated for its adjuvant effects on the immunity of a DNA vaccine carrying the GP5 gene of PRRSV. Groups of mice were immunized twice at 2-week interval with 100 μg of the plasmid DNA vaccine pcDNA3.1-SynORF5, pcDNA3.1-PoIFN-λ1-SynORF5, and the blank vector pcDNA3.1, respectively. The results showed that pcDNA3.1-PoIFN-λ1-SynORF5 can significantly enhance GP5-specific ELISA antibody, PRRSV-specific neutralizing antibody, IFN-γ level, and lymphocyte proliferation ratherthan the responses induced by pcDNA3.1-SynORF5. Therefore, type III interferon PoIFN-λ1 could enhance the immune responses of DNA vaccine of PRRSV, highlighting the potential value of PoIFN-λ1 as a molecular adjuvant in the prevention of PRRSV infection. © 2013 Luping Du et al. Source

Bi Z.,Jiangsu Academy of Agricultural Sciences | Bi Z.,Key Laboratory of Veterinary Biological Engineering and Technology | Bi Z.,National Center for Engineering Research of Veterinary Bio products | Bi Z.,Jiangsu Electric Power Company | And 12 more authors.
Archives of Virology | Year: 2014

Canine distemper virus (CDV) infects a broad range of carnivores, including wild and domestic Canidae. The hemagglutinin gene, which encodes the attachment protein that determines viral tropism, has been widely used to determine the relationship between CDV strains of different lineages circulating worldwide. We determined the full-length H gene sequences of seven CDV field strains detected in domestic dogs in Nanjing, China. A phylogenetic analysis of the H gene sequences of CDV strains from different geographic regions and vaccine strains was performed. Four of the seven CDV strains were grouped in the same cluster of the Asia-1 lineage to which the vast majority of Chinese CDV strains belong, whereas the other three were clustered within the Asia-4 lineage, which has never been detected in China. This represents the first record of detection of strains of the Asia-4 lineage in China since this lineage was reported in Thailand in 2013. © 2014, Springer-Verlag Wien. Source

Wen L.,Jiangsu Academy of Agricultural Sciences | Wen L.,Key Laboratory of Veterinary Biological Engineering and Technology | Wen L.,National Center for Engineering Research of Veterinary Bio products | Wang F.,Jiangsu Academy of Agricultural Sciences | And 17 more authors.
Archives of Virology | Year: 2015

Porcine circovirus type 2 (PCV2) is the causal agent of a serious disease found in pigs. Here, we report the first detection of truncated genome sequences of PCV2 strain ZJ-R, with the genomic region encoding part of Rep and Cap with a nonviral insertion. To our knowledge, the genome of ZJ-R represents the first PCV2 DNA with a coding insertion. The PCV2 ZJ-R genome is 694 nucleotides long and has two main open reading frames. The whole genome sequence of ZJ-R may facilitate further study of the origin and evolution of PCV2. © 2014, Springer-Verlag Wien. Source

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