ABSTRACT
The hemagglutinin (HA) gene of A/Swine/Inner Mogolian/547/2001 (H3N2) swine influenza virus (SIV) was recombined into the genome of pseudorabies virus (PRV) Bartha-K61 vaccine strain, generating a recombinant PRV expressing the HA gene, designated as rPRV-HA. One group of 15 mice was inoculated intranasally (i.n.) with 10(5.0) PFU of rPRV-HA, and another two control groups of mice (15 mice per group) were mock-inoculated or inoculated with Bartha-K61. Mice inoculated with rPRV-HA developed hemagglutination inhibition antibodies 3 weeks post-inoculation. Twenty-eight days post-inoculation, all mice were challenged i.n. with 10(5.0) TCID50 of A/Swine/Heilongjiang/74/2000 (H3N2). No challenge virus was isolated from vaccinated mice, and mild pathological lesions were observed only in lungs following challenge. The results demonstrate that the recombinant rPRV-HA expressing the HA gene from H3N2 SIV can protect mice from heterologous virulent challenge, and may represent a candidate vaccine against SIV.
Subject(s)
Hemagglutinins/immunology , Influenza A Virus, H3N2 Subtype/immunology , Influenza Vaccines/immunology , Lung Diseases/veterinary , Orthomyxoviridae Infections/prevention & control , Orthomyxoviridae Infections/veterinary , Swine Diseases/prevention & control , Swine Diseases/virology , Animals , Antibodies, Viral/blood , Base Sequence , Chick Embryo , Chlorocebus aethiops , Hemagglutination Inhibition Tests/veterinary , Hemagglutinins/genetics , Herpesvirus 1, Suid/genetics , Histocytochemistry/veterinary , Influenza A Virus, H3N2 Subtype/genetics , Influenza Vaccines/genetics , Influenza Vaccines/pharmacology , Lung Diseases/immunology , Lung Diseases/prevention & control , Lung Diseases/virology , Mice , Molecular Sequence Data , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/virology , Random Allocation , Swine , Swine Diseases/immunology , Vaccination/veterinary , Vero CellsABSTRACT
To screen small animals susceptible to SARS-CoV, five species of animals, including guinea pig, hamster, albino hamster, chicken and rat, were experimentally infected with SARS-CoV strain BJ-01 by different routes. On the basis of this, further cynomolgus and rhesus macaques were selected and experimentally inoculated SARS-CoV, the quality they serve as animal model for SARS was evaluated. The results showed that, all five species of small animals chosed were not susceptible to SARS-CoV, no characterized changes in clinical sign and histopathology were observed after infection, but from the lung samples of large rat and pig guinea, the genomic RNA of SARS-CoV could be detected by RT-PCR at day 14 post infection, this suggested that SARS-CoV could replicate in these animals. After inoculated with SARS-CoV, all inoculated cynomolgus and rhesus macaques had developed interstitial pneumonia of differing severity. These changes on histopathology were similar to that seen in SARS patients, but the pathological lesions were less severe than that of human. Except interstitial pneumonia, no other characterized pathological changes were observed. This suggested cynomolgus and rhesus macaques were not the ideal animal model for SARS in fact, but they could serve as animal model for SARS when a more ideal animal model is absent.
