Our results showed that NDV can tolerate an IGS length of at least 365 nt. The extended lengths of IGSs down-regulated the transcription of the downstream gene and suggested that 31 nt in the F-HN IGS and 47 nt in the HN-L IGS are required for efficient transcription of the downstream gene. The effect of IGS length on pathogenicity of mutant viruses was evaluated in embryonated chicken eggs, 1-day-old chicks, and 6-week-old chickens. Our BAY 80-6946 price results showed

that all IGS mutants were attenuated in chickens. The level of attenuation increased as the length of the IGS increased. Interestingly, decreased IGS length also attenuated the viruses. These findings can have significant applications in NDV vaccine development.”
“Hantavirus

pulmonary syndrome (HPS) is a highly pathogenic disease (40% case fatality rate) carried by rodents chronically Selleck BAY 11-7082 infected with certain viruses within the genus Hantavirus of the family Bunyaviridae. The primary mode of transmission to humans is thought to be inhalation of excreta from infected rodents; however, ingestion of contaminated material and rodent bites are also possible modes of transmission. Person-to-person transmission of HPS caused by one species of hantavirus, Andes virus (ANDV), has been reported. Previously, we reported that ANDV injected intramuscularly causes a disease in Syrian hamsters that closely resembles HPS in humans. Here we tested whether ANDV was lethal in hamsters when it was administered by routes that more accurately model the most common routes of human

infection, i.e., the subcutaneous, intranasal, and intragastric routes. We discovered that ANDV was lethal by all three routes. Remarkably, even at very low doses, ANDV was highly pathogenic when it was introduced by the mucosal routes (50% lethal dose [LD50], similar to 100 PFU). We performed passive transfer experiments to test the capacity of neutralizing antibodies to protect against lethal intranasal Sodium butyrate challenge. The neutralizing antibodies used in these experiments were produced in rabbits vaccinated by electroporation with a previously described ANDV M gene-based DNA vaccine, pWRG/AND-M. Hamsters that were administered immune serum on days -1 and +5 relative to challenge were protected against intranasal challenge (21 LD50). These findings demonstrate the utility of using the ANDV hamster model to study transmission across mucosal barriers and provide evidence that neutralizing antibodies produced by DNA vaccine technology can be used to protect against challenge by the respiratory route.”
“Neutralizing monoclonal antibodies (MAbs) are increasingly being considered for blunting human viral infections. However, whether they can also exert indirect effects on endogenous antiviral immune responses has been essentially overlooked.