Optimal transfection methods and comparison of PK-15 and Dulac cells for rescue of chimeric porcine circovirus type 1-2

- Electrotransfection and lipofection parameters were optimized of Dulac cells for elevating the efficiency of rescuing infectious PCV1-2.
- Electrotransfection and lipofection methods were effective at delivering the pBSK(+)-dPCV1-2 plasmid to Dulac cells.
- Dulac cells were more permissive to PCV1-2 than PK-15 cells regardless of transfection technique.
- PCV1-2 viral particles were observed using an electron microscopy, and icosahedral rescued virus particles with uniform shape were observed, with an approximate diameter of 17 nm.

A chimeric porcine circovirus type 1-2 (PCV1-2) infectious DNA clone has low transfection efficiency and exhibits low levels of proliferation. Electroporation and lipofection parameters were optimized for PK-15 and Dulac cells with the purpose of increasing the efficiency for rescuing infectious PCV1-2. Titers of PCV1-2 in Dulac cells were 100-fold higher than those in PK-15 cells following transfection. The electroporation efficiency into Dulac cells was high when three 400 μs pulses at 250 V with 6 μg of plasmid DNA was used, lipofection efficiency was high when the ratio of DNA to transfection reagent was 1:3. The proportion of infected cells was 55.6% compared with 44.2%, for the electroporation and lipofection techniques respectively. Virus titers were higher in Dulac cells, from 104.44 to 105.32 TCID50/mL compared with 101.90-103.38 TCID50/mL for PK-15 cells. Dulac cells were more permissive to PCV1-2 than PK-15 cells regardless of the transfection technique.