Schematic diagram of PCV2 ORF2 chimeras and mutants and their reactivity with PCV2-positive serum and mAb 8E4. (a) PCV2 clones rCL-ORF2 and rYJ-ORF2 contained the complete 233 aa sequence of PCV2a/CL-ORF2 and the 235 aa sequence of PCV2b/YJ-ORF2, respectively. Five chimeras that consisted of aa 47-72 (rCL-YJ-1), 80-94 (rCL-YJ-2), 110-154 (rCL-YJ-3), 190-210 (rCL-YJ-4) and 230-235 (rCL-YJ-5) of the PCV2a/CL capsid protein were replaced with corresponding regions of the PCV2b/YJ capsid protein. (b) For the second set of constructs, four mutants containing single amino acid mutations of PCV2a/CL-ORF2 at positions 51 (rCL-YJ-1-51), 57 (rCL-YJ-1-57), 59 (rCL-YJ-1-59) and 63 (rCL-YJ-1-63) were substituted for the corresponding amino acids of the PCV2b/YJ capsid protein at the same position. (c) PCV2 clones rLG-ORF2 and rJF2-ORF2 contained the complete 233 aa sequences of PCV2a/LG-ORF2 and the 236 aa sequences of PCV2a/JF2-ORF2, respectively. The PCV2 mutants rLG-YJ-1-59 and rJF2-YJ-1-59 contained a single amino acid mutation from alanine to arginine at position 59 (A59R) in the capsid protein of PCV2a/LG and PCV2a/JF2, respectively. The last mutant rYJ-CL-1-59 contained a single amino acid mutation of arginine for alanine at position 59 (R59A) in the capsid protein of PCV2b/YJ. The IPMA reactivity between each antibody and PK-15 cells transfected with each PCV2 construct is indicated next to each construct. The IPMA reactivity of the constructs in transfected PK-15 cells was demonstrated by PCV2-positive serum and mAb 8E4. +: Positive; -: Negative.
Huang et al. BMC Microbiology 2011 11:188 doi:10.1186/1471-2180-11-188