Abstract
Since May 2006, a highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) has emerged and prevailed in mainland China, affecting over 2 million pigs. Commercial PRRSV killed and modified live vaccines cannot provide complete protection against HP-PRRSV due to genetic variation. Development of more effective vaccines against the emerging HP-PRRSV is urgently required. In our previous studies, two formulations of DNA vaccines (pcDNA3.1-PoIFN-λ1-SynORF5 and BPEI/PLGA-SynORF5) based on the HP-PRRSV were constructed and shown to induce enhanced humoral and cellular immune responses in mice. The objective of this study was to evaluate the immune response induced by these novel formulations in piglets. PcDNA3.1-PoIFN-λ1-SynORF5 and BPEI/PLGA-SynORF5 vaccines induced significantly enhanced GP5-specific antibody and PRRSV-specific neutralizing antibody in pigs compared with the pcDNA3.1-SynORF5 parental construct. Though IFN-γ levels and lymphocyte proliferation responses induced by the two DNA vaccine formulations were comparable to that induced by the pcDNA3.1-SynORF5 construct, each of the novel formulations provided efficient protection against challenge with HP-PRRSV. Non-severe clinical signs and rectal temperatures were observed in pigs immunized with BPEI/PLGA-SynORF5 compared with other groups. Thus, these novel DNA constructs may represent promising candidate vaccines against emerging HP-PRRSV.
Highlights
Porcine reproductive and respiratory syndrome (PRRS) is an economically frustrating viral disease of pigs, characterized by severe reproductive failure in pregnant sows, and respiratory disorders in piglets and growing pigs[1]
We evaluated the immune responses in piglets induced by inoculation with one of two formulations of DNA vaccines, pcDNA3.1-PoIFN-λ1 -SynORF5 and BPEI/poly(lactic-co-glycolic acid) (PLGA)-SynORF5, which were prepared during our previous research
There was no significant difference in the level of GP5 antibody between the group immunized with the BPEI/PLGA-SynORF5 construct and JXA1-R
Summary
Porcine reproductive and respiratory syndrome (PRRS) is an economically frustrating viral disease of pigs, characterized by severe reproductive failure in pregnant sows, and respiratory disorders in piglets and growing pigs[1]. We constructed a recombinant plasmid, pcDNA3.1-SynORF5, based on the HP-PRRSV JSKM strain. Data are presented as the mean ±S.E.M. with the molecular adjuvant PoIFN-λ1 or BPEI/PLGA nanoparticles, which were demonstrated to improve the immunogenicity of the pcDNA3.1-SynORF5 DNA construct in mice[1,12]. Poly(D, L-lactide-co-glycolide) (PLGA) nanoparticle-mediated delivery of vaccines has been shown to be effective in eliciting a protective immune response, and these particles can be administered by either the mucosal or the systemic route[14,15]. Polyethylenimine (PEI), as a cationic polymer, has been widely used to modify PLGA particles in order to enhance the efficiency of adsorption of DNA onto PLGA nanoparticles[12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
