RESUMO
Adult C57BL/6J mice have been used to study Foot-and-mouth disease virus (FMDV) biology. In this work, two variants of an FMDV A/Arg/01 strain exhibiting differential pathogenicity in adult mice were identified and characterized: a non-lethal virus (A01NL) caused mild signs of disease, whereas a lethal virus (A01L) caused death within 24-48h independently of the dose used. Both viruses caused a systemic infection with pathological changes in the exocrine pancreas. Virus A01L reached higher viral loads in plasma and organs of inoculated mice as well as increased replication in an ovine kidney cell line. Complete consensus sequences revealed 6 non-synonymous changes between A01L and A10NL genomes that might be linked to replication differences, as suggested by in silico prediction studies. Our results highlight the biological significance of discrete genomic variations and reinforce the usefulness of this animal model to study viral determinants of lethality.
Assuntos
Vírus da Febre Aftosa/patogenicidade , Febre Aftosa/patologia , Febre Aftosa/virologia , Interações Hospedeiro-Patógeno , Replicação Viral , Estruturas Animais/virologia , Animais , Linhagem Celular , Modelos Animais de Doenças , Vírus da Febre Aftosa/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Mutação de Sentido Incorreto , Pâncreas/patologia , Plasma/virologia , Análise de Sequência de DNA , Análise de Sobrevida , Carga ViralRESUMO
Foot and mouth disease is caused by a non-enveloped virus (FMDV), which disposes several antigenic sites at the surface of their capsid proteins. The most relevant and immunodominant antigenic site of FMDV (site A or AnSA) includes a key virus-cell interaction element (RGD motif) located in the Viral Protein 1 (VP1), more precisely at the GH loop. AnSA includes a set of overlapped and mainly linear epitopes, which are the main targets of the humoral immune response. Taking advantage over specific structural features of the GH loop, we have evaluated the influence of every amino acid residue at AnSA in the interaction with 2 neutralizing antibodies by molecular modeling techniques. Additionally, we constructed diverse interaction complexes with multiple site A mutants and discussed about the structural influence of amino acidic insertions in such relevant antigenic site of FMDV. Our approach is in agreement with previous ELISA experiments and allows the understanding of how FMDV mutations may alter the interaction with different antibodies, as we can estimate the contribution of each amino acid to the interaction. Overall, our work contributes to the development of specific vaccination strategies for FMD control.
