Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1999 Dec;73(12):9891-8.
doi: 10.1128/JVI.73.12.9891-9898.1999.

Ability of foot-and-mouth disease virus to form plaques in cell culture is associated with suppression of alpha/beta interferon

J Chinsangaram  1 , M E Piccone, M J Grubman
Affiliations

Ability of foot-and-mouth disease virus to form plaques in cell culture is associated with suppression of alpha/beta interferon

J Chinsangaram et al. J Virol. 1999 Dec.

Abstract

A genetic variant of foot-and-mouth disease virus lacking the leader proteinase coding region (A12-LLV2) is attenuated in both cattle and swine and, in contrast to wild-type virus (A12-IC), does not spread from the initial site of infection after aerosol exposure of bovines. We have identified secondary cells from susceptible animals, i.e., bovine, ovine, and porcine animals, in which infection with A12-LLV2, in contrast to A12-IC infection, does not produce plaques; this result indicates that this virus cannot spread from the site of initial infection to neighboring cells. Nevertheless, A12-LLV2 can infect these cells, but cytopathic effects and virus yields are significantly reduced compared to those seen with A12-IC infection. Reverse transcription-PCR analysis demonstrates that both A12-LLV2 and A12-IC induce the production of alpha/beta interferon (IFN-alpha/beta) mRNA in host cells. However, only supernatants from A12-LLV2-infected cells have significant antiviral activity. The antiviral activity in supernatants from A12-LLV2-infected embryonic bovine kidney cells is IFN-alpha/beta specific, as assayed with mouse embryonic fibroblast cells with or without IFN-alpha/beta receptors. The results obtained with cell cultures demonstrate that the ability of A12-IC to form plaques is associated with the suppression of IFN-alpha/beta expression and suggest a role for this host factor in the inability of A12-LLV2 to spread and cause disease in susceptible animals.

PubMed Disclaimer

Figures

FIG. 1
FIG. 1
Titers of A12-IC and A12-LLV2 on different cells. BHK-21, LK, EBK, and PK cells were infected with A12-IC (□) and A12-LLV2 (▨). Cells were overlaid and incubated for 48 h before staining. A12-LLV2 did not form plaques on LK, EBK, and PK cells and is reported as having no titer detectable on these cell types in a plaque assay.
FIG. 2
FIG. 2
Plaque titration on EBK cells. EBK cells were infected with A12-LLV2 (A) at MOIs of 10, 1, and 0.1 (from left to right) or A12-IC (B) at MOIs of 0.01, 0.001, and 0.0001 (from left to right) at 37°C for 1 h and then overlaid. Cells were stained at 48 h postinoculation.
FIG. 3
FIG. 3
Single-step growth curve. BHK-21, EBK, LK, and PK cells were infected with A12-LLV2 (○) or A12-IC (●) at an MOI of 10 at 37°C. After 1 h, cells were rinsed with 150 mM NaCl–20 mM MES (pH 6.0) and incubated in MEM at 37°C. Supernatants were collected from the infected cells at 1, 2, 4, 6, 7, and 24 h postinoculation and titrated on BHK-21 cells.
FIG. 4
FIG. 4
CPE in A12-IC- and A12-LLV2-infected EBK cells. EBK cells were infected with A12-IC or A12-LLV2 or mock infected at an MOI of 10 at 37°C for 1 h and then incubated in MEM. Cells were formalin fixed at 3, 4, 6, 8, and 24 h postinoculation (PI).
FIG. 5
FIG. 5
Protein synthesis in A12-IC- and A12-LLV2-infected EBK cells. EBK cells were infected with A12-IC or A12-LLV2 for 1 h and radiolabelled with [35S]methionine at various times postinoculation for 1 h. Cells were lysed, and equal volumes of cytoplasmic extracts were analyzed by sodium dodecyl sulfate–15% PAGE. Lane 1 is a cytoplasmic extract of mock-infected EBK cells (M). Lanes 2 to 6 show proteins from A12-IC-infected EBK cells radiolabelled at 2, 3, 4, 5, and 6 h postinoculation, respectively. Lanes 7 to 11 show proteins from A12-LLV2-infected EBK cells radiolabelled at 2, 3, 4, 5, and 6 h postinoculation, respectively. Host cell proteins revealed in mock-infected and infected cells are indicated by asterisks.
FIG. 6
FIG. 6
Reduction of virus yield in the presence of antiviral activity. PK cells were infected with approximately 100 PFU of A12-IC; at 1, 2, 3, and 4 hpi, the supernatants were replaced with a 1:10 dilution of treated supernatants from A12-LLV2-infected PK cells (■), mock-infected PK cells (▨), or medium alone (▧) for a total of 48 h. The growth of A12-IC was determined in a subsequent plaque titration assay on BHK-21 cells.
FIG. 7
FIG. 7
RT-PCR for IFN-α and IFN-β mRNAs. EBK cells were infected with A12-IC or A12-LLV2 or mock infected for 6 h and used in RT-PCR as described in Materials and Methods. Aliquots from RT reactions were used in three separate PCR assays with IFN-α, IFN-β, and β-actin primers. RT-PCR products from EBK cells infected with A12-IC (IC) or A12-LLV2 (LLV) or mock infected (M) in the presence or absence of reverse transcriptase (RT) are shown. IFN-α (A), IFN-β (B), and β-actin (B) RT-PCR products are 379, 452, and 890 bp, respectively. Lanes MW are 1-kb ladder DNA molecular weight markers.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Bachrach H L. Foot-and-mouth disease: world-wide impact and control measures. In: Kurstak E, Maramorosch K, editors. Viruses and environment. New York, N.Y: Academic Press, Inc.; 1978. pp. 299–310.
    1. Beck E, Strohmaier K. Subtyping of European foot-and-mouth disease virus strains by nucleotide sequence determination. J Virol. 1987;61:1621–1629. - PMC - PubMed
    1. Black T L, Safer B, Hovanessian A, Katze M G. The cellular 68,000-Mr protein kinase is highly autophosphorylated and activated yet significantly degraded during poliovirus infection: implications for translational regulation. J Virol. 1989;63:2244–2251. - PMC - PubMed
    1. Brown C C, Piccone M E, Mason P W, McKenna T S-C, Grubman M J. Pathogenesis of wild-type and leaderless foot-and-mouth disease virus in bovines. J Virol. 1996;70:5638–5641. - PMC - PubMed
    1. Brown F. New approaches to vaccination against foot-and-mouth disease. Vaccine. 1992;10:1022–1026. - PubMed

Publication types

LinkOut - more resources