106 results about "Viremia" patented technology

Previously, we showed that type I interferon (alpha / beta interferon [IFN-α / β]) can inhibit foot-and-mouth disease virus (FMDV) replication in cell culture, and swine inoculated with 109 PFU of human adenovirus type 5 expressing porcine IFN-α (Ad5-pIFN-α) were protected when challenged 1 day later. In this study, we found that type II pIFN (pIFN-γ) also has antiviral activity against FMDV in cell culture and that, in combination with pIFN-α, it has a synergistic antiviral effect. We also observed that while each IFN alone induced a number of IFN-stimulated genes (ISGs), the combination resulted in a synergistic induction of some ISGs. To extend these studies to susceptible animals, we inoculated groups of swine with a control Ad5, 108 PFU of Ad5-pIFN-α, low- or high-dose Ad5-pIFN-γ, or a combination of Ad5-pIFN-α and low- or high-dose Ad5-pIFN-γ and challenged all groups with FMDV 1 day later. The control group and the groups inoculated with either Ad5-pIFN-α or a low dose of Ad5-pIFN-γ developed clinical disease and viremia. However, the group that received the combination of both Ad5-IFNs with the low dose of Ad5-pIFN-γ was completely protected from challenge and had no viremia. Similarly the groups inoculated with the combination of Ad5s with the higher dose of Ad5-pIFN-γ or with only high-dose Ad5-pIFN-γ were protected. The protected animals did not develop antibodies against viral nonstructural (NS) proteins, while all infected animals were NS protein seropositive. No antiviral activity or significant levels of IFNs were detected in the protected groups, but there was an induction of some ISGs. The results indicate that the combination of type I and II IFNs act synergistically to inhibit FMDV replication in vitro and in vivo.

The invention discloses a gene-deleted attenuated African swine fever virus strain, a construction method and application thereof, and belongs to the technical field of biological vaccine products. The gene-deleted attenuated African swine fever virus strain constructed by the homologous recombination method of the present invention is based on the type II African swine fever virus genome and simultaneously deletes CD2v, MGF (12L, 13L, 14L) and I177L gene fragments The gene deletion virus strain is obviously attenuated relative to the parental strain, and will not affect the stable replication and immunogenicity of the gene deletion virus strain. After being inoculated into experimental pigs, there will be no obvious rise in body temperature, joint swelling, disease or death of experimental pigs, and no viremia, showing good safety and good immune challenge protection effect. Therefore, the gene-deleted attenuated African swine fever virus strain provided by the present invention can be used as a candidate vaccine strain with good safety and immune protection effect.