| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 3428669 | Virus Research | 2013 | 10 Pages |
The objective of this study was to compare the mRNA expression of host genes involved in type-I interferon-induced antiviral state (IFN-α, IFN-β, Mx-1, PKR, OAS-1 and ISG-15), and apoptosis (caspase-3, -8, and -9), after experimental infection of beef calves with low or high virulence noncytopathic (ncp) bovine viral diarrhea virus (BVDV) strains. Thirty BVDV-naïve, clinically normal calves were randomly assigned to three groups. Calves were intranasally inoculated with low (LV; n = 10, strain SD-1) or high (HV; n = 10, strain 1373) virulence ncp BVDV or BVDV-free cell culture medium (Control, n = 10). Quantitative RT-PCR was used to determine the target gene expression in tracheo-bronchial lymph nodes and spleen 5 days after infection. Interferon-α and -β mRNA levels were up-regulated in tracheo-bronchial lymph nodes (P < 0.05) in the HV group, but not in the LV group, compared with the control group. There was an up-regulation of type I interferon-induced genes in spleen and tracheo-bronchial lymph nodes of HV and LV groups, compared with the control group (P < 0.01). mRNA levels of OAS-1 and ISG-15 were significantly higher in LV than HV calves (P < 0.05). A significant up-regulation of caspase-8 and -9 was observed in tracheo-bronchial lymph nodes in the LV group (P = 0.01), but not in the HV group. In conclusion, experimental infection with either high or low virulence BVDV strains induced a significant expression of the type I interferon-induced genes in beef calves. There was a differential expression of some interferon-induced genes (OAS-1 and ISG-15) and pro-apoptosis markers based on BVDV virulence and genotype.
► IFN-α and -β were upregulated 5 days post infection with BVDV-2 but not with BVDV-1. ► BVDV infection (high or low virulence) upregulated type I interferon-induced genes. ► BVDV-1 infection induced higher expression of OAS-1 and ISG-15 than BVDV-2 infection. ► Upregulation of caspase-8 and -9 was only observed in calves infected with BVDV-1.
