“…The PCV2-ORF3 polyclonal antibody (PAb) was a kind gift from Jimmy Kwang of the Animal Health Biotechnology Group, Temasek Life Sciences Laboratory, National University of Singapore (25). Eukaryotic expression plasmids pCI-neo-PCV2-ORF1, -ORF2, -ORF3 (23,26), and -ORF4, as well as the plasmids pEGFP-PCV2-ORF1, -ORF2, -ORF3, -ORF4, and pEGFP-PCV1-ORF4 (our unpublished constructs), were maintained in our laboratory. Seven-week-old specificpathogen-free (SPF) BALB/c mice were purchased from the Shanghai Laboratory Animal Center, Chinese Academy of Sciences, Shanghai, China.…”