Evaluation of Cell Lines for the Isolation of Foot-and-Mouth Disease Virus and Other Viruses Causing Vesicular Disease

Abstract

The most sensitive cell culture system for the isolation of foot-and-mouth disease virus (FMDV) is primary bovine thyroid (BTY) cells. However, BTY cells are seldom used because of the challenges associated with sourcing thyroids from FMDV-negative calves (particularly in FMD endemic countries), and the costs and time required to regularly prepare batches of cells. Two continuous cell lines, a fetal goat tongue cell line (ZZ-R 127) and a fetal porcine kidney cell line (LFBK-α V β 6), have been shown to be highly sensitive to FMDV. Here, we assessed the sensitivity of ZZ-R 127 and LFBK-α V β 6 cells relative to primary BTY cells by titrating a range of FMDV original samples and isolates. Both the ZZ-R 127 and LFBK-α V β 6 cells were susceptible to FMDV for >100 passages, and there were no significant differences in sensitivity relative to primary BTY cells. Notably, the LFBK-α V β 6 cell line was highly sensitive to the O/CATHAY porcine-adapted FMDV strain. These results support the use of ZZ-R 127 and LFBK-α V β 6 as sensitive alternatives to BTY cells for the isolation of FMDV, and highlight the use of LFBK-α V β 6 cells as an additional tool for the isolation of porcinophilic viruses.

Elimination of Non-cytopathic Bovine Viral Diarrhea Virus From the LFBK-αvβ6 Cell Line

“…The analytical sensitivity of the WRL- LFBK-α v β 6 culture was comparable to the original BVDV-infected LFBK-α v β 6 cell line when titrations of FMDV, SVDV, VSV, VESV, and SVV were tested ( Table 1 ). These data support the use of WRL- LFBK-α v β 6 for FMD and vesicular disease diagnostics, with the findings in agreement to those previously reported in Gray et al ( 4 ).…”

“…The LFBK-α v β 6 cell line [( 1 ), correction ( 2 )], supplied by the Plum Island Animal Disease Center (New York, USA), was maintained as previously described ( 4 ). Briefly, LFBK-α v β 6 cells (passage 19) were grown in a 175 cm 2 cell filter-cap tissue culture flask (Cellstar, Greiner Bio-One) at 37°C in the presence of 5% CO 2 until the monolayer reached 90–100% confluency.…”

“…Representative vesicular disease viruses were selected for testing from the WRLFMD collection. FMDV/O/KUW/4/2016 original suspension was prepared as described in Gray et al ( 4 ) from vesicular epithelium, and is used to routinely monitor primary and continuous cell line batch-to-batch variation. In addition, the following viruses were selected for testing: swine vesicular disease virus (SVDV) UKG/77/1980 RS1, vesicular stomatitis virus (VSV) IND-1 BHK5, vesicular exanthema of swine virus (VESV) D53 PK5 RS3, and Seneca Valley virus (SVV) MN-88-36695 SK?…”

“…We previously validated the use of LFBK-α V β 6 cells for diagnostic purposes within the World Reference Laboratory for FMD (WRLFMD) ( 4 ). Our results demonstrated that LFBK-α V β 6 cells had similar analytical sensitivity to FMDV epithelium suspensions as primary bovine thyroid cells (BTY), which had previously been identified as the most sensitive cell system for FMDV isolation ( 5 ).…”

“…Our results demonstrated that LFBK-α V β 6 cells had similar analytical sensitivity to FMDV epithelium suspensions as primary bovine thyroid cells (BTY), which had previously been identified as the most sensitive cell system for FMDV isolation ( 5 ). Additionally, the LFBK-α V β 6 cells had enhanced susceptibility to porcine-adapted FMDVs compared to IB-RS-2 cells ( 4 ). Unfortunately, the LFBK-α V β 6 cell line is persistently infected with a non-cytopathic bovine diarrhea virus (BVDV; family Flaviviridae , genus Pestivirus ) (Rodriguez, personal communication), which complicates the use of these cells due to concerns about cross-contamination of other cell lines and downstream applications, including vaccine production and preparation of challenge viruses for in vivo studies.…”