Fibroblast growth factor 11 inhibits foot-and-mouth disease virus gene expression and replication in vitro

Figures

• 

  Fig. 1.. Construction and evaluation of foot-and-mouth disease virus (FMDV) five prime untranslated region (5′ UTR)-luci reporter system. (A) Construction of FMDV 5′ UTR-luci reporter plasmid. The gene fragment of FMDV 5′ UTR region was obtained using Asia1 Shamir (R) strain (JF739177.1) as a template. We got a luciferase gene using pGL3b as a template. FMDV 5′ UTR gene was ligated with pcDNA3. After ligation, we finally prepared pcDNA3/5′ UTR-Luci reporter system. (B) Confirmation of FMDV 5′ UTR-luci expression in cells. 5′ UTR RNA region was determined by RT-PCR after transfection of FMDV 5′ UTR-luci plasmid. (C) Evaluation of FMDV 5′ UTR-derectid luciferase expression. Increased luciferase activities were confirmed in a dose-dependent manner of pcDNA3/5′ UTR-luci plasmid transfection.

• 

  Fig. 2.. Fibroblast growth factor 11 (FGF11) inhibits foot-and-mouth disease virus (FMDV) five prime untranslated region (5′ UTR)-directed translation. (A) Ribavirin increases FMDV 5′ UTR-directed translation. After transfection of 5′ UTR-luci reporter, ribavirin was treated to cells. (B) CoCl2 increases FMDV 5′ UTR-directed translation. Data shown are means ± SD of three independent experiments performed in duplicate. (C) FGF11 decreases FMDV 5′ UTR-directed translation. FGF11 gene was transfected together with 5′ UTR-luci reporter. After 24 hr post-transfection, cells were applied to measure luciferase activity. FGF11 expression was confirmed in a dose-dependent manner. **P<0.01, *P<0.05 compared with mock-transfected cells. (D) Farnesoid X receptor alpha (FXRα) expression do not affect FMDV 5′ UTR-directed translation. FXRα gene was transfected together with 5′ UTR-luci reporter. The experiments were similarly performed as in (C). (E) FGF11 overexpression does not affect cell viability. After increasing amounts of FGF11 transfection, we measured the cell viability by CCK-8.

• 

  Fig. 3.. Fibroblast growth factor 11 (FGF11) inhibits foot-and-mouth disease virus (FMDV) replication in FMDV-infected cells. (A) FGF11 expression decreased FMDV 3D gene expression in FMDV-infected cells. After 24 hr post-transfection of FGF11 gene, FMDV Asia1 Shamir (R) strain was infected to IBRS-2 cells. Within 24 hr post-infection of FMDV, we measured FMDV 3D RNA level by qPCR. (B) Expression level of FGF11 was determined by qPCR and normalized to β-actin.

• 

  Fig. 4.. Fibroblast growth factor 11 (FGF11) inhibits cytopathic effect (CPE) induction in foot-and-mouth disease virus (FMDV)-infected cells. (A) IBRS-2 cells were transfected with pFlag-CMV2/FGF11 plasmid with different amounts. After 24 hr post-transfection, FMDV Asia1 Shamir (R) strain was infected IBRS-2 cells according to 103 TCID50 for 1 hr. After 24 hr post-infection, cytopathic effect was evaluated by microscope and numbered by a represented graph. (B) Expression level of FGF11 was determined by qPCR and normalized to β-actin. (C) Samples were collected every 24 hr postinfection (x axis) and were quantified by TCID50 (y axis) in the presence or absence of FGF11 expression. The experiment was performed in triplicates. TCID50 values were calculated by using Karber method.