RESUMO
The Chinese equine infectious anemia virus (EIAV) donkey-leukocyte attenuated vaccine (DLV) provides a unique natural model system to study the attenuation mechanism and immunological control of lentivirus replication. Critical consensus mutations were identified between virulent Chinese EIAV strains and vaccine strains. Based on a full-length infectious clone of EIAV vaccine strain pLGFD3, two molecular clones, mFD5-4-7 and mFD7-2-11, were successfully constructed, in which 4 and 6 critical consensus mutations in the env gene of the vaccine strain were point-mutated to the wild-type sequence, respectively by an overlap PCR mutagenesis strategy. The infectivity, virulence, and pathogenesis of the constructed clones were investigated in vitro using a reverse transcriptase assay, an indirect immunofluorescence assay, observation of cytopathogenic effect, and virion observation as well as in vivo by inoculation of animals with the resulting infectious clones. The pathogenic symptoms in horses inoculated with mFD7-2-11 were more severe than those inoculated with mFD5-4-7, whereas no pathogenic symptoms were detected in animals inoculated with their parental clone pLGFD3 strain. The results indicate that the consensus mutation residues of the env region involved in this study play significant roles in the virulence and pathogenicity of EIAV. This will contribute to the elucidation of the attenuating and protective mechanisms of the Chinese EIAV vaccine.
Assuntos
Substituição de Aminoácidos , Genes env , Vírus da Anemia Infecciosa Equina/genética , Vírus da Anemia Infecciosa Equina/patogenicidade , Mutação Puntual , Sequência de Aminoácidos , Animais , Temperatura Corporal , Linhagem Celular , Efeito Citopatogênico Viral , Modelos Animais de Doenças , Equidae , Anemia Infecciosa Equina/fisiopatologia , Anemia Infecciosa Equina/virologia , Técnica Direta de Fluorescência para Anticorpo , Produtos do Gene env/química , Produtos do Gene env/genética , Cavalos , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Contagem de Plaquetas , Alinhamento de Sequência , Vacinas Atenuadas/genética , Vacinas Virais/genética , Virulência/genéticaRESUMO
In this study, goats were experimentally infected with caprine arthritis-encephalitis virus (CAEV). Anti-CAEV antibodies were detected in vivo using indirect enzyme-linked immunosorbent assay (ELISA) and Western blot assays. The results showed that the sensitivity of detection of anti-CAEV antibodies using indirect ELISA was relatively high, whereas Western blotting was very sensitive for detection of P28 anti-CAEV antibody as 4 days postinfection. Apparently, because of high immunogenicity of P28 antigen, the detection of antibodies specific for this viral protein may represent a valuable assay to detect early infection. CAEV related to other lentiviruses may be useful in studies of human immunodeficiency virus (HIV) and related viruses in animal models.
