Poster (Painel)
| MH-001 |
Quasispecies detection in human respiratory syncytial virus (HRSV) samples in absence and presence of polyclonal serum
| | Autores: | Claudia Trigo Pedroso de Moraes (IB - Instituto ButantanICB - USP - Universidade de São Paulo - Instituto de Ciências Biomédicas) ; Viviane Fongaro Botosso (IB - Instituto Butantan) ; Danielle Bruna Leal Oliveira (ICB - USP - Universidade de São Paulo - Instituto de Ciências Biomédicas) ; Angélica Cristine de Almeida Campos (ICB - USP - Universidade de São Paulo - Instituto de Ciências Biomédicas) ; Patricia Alves Bosso (ICB - USP - Universidade de São Paulo - Instituto de Ciências Biomédicas) ; Hildêner Lima (ICB - USP - Universidade de São Paulo - Instituto de Ciências Biomédicas) ; Klaus Eberhard Stewien (ICB - USP - Universidade de São Paulo - Instituto de Ciências Biomédicas) ; Edison Luiz Durigon (ICB - USP - Universidade de São Paulo - Instituto de Ciências Biomédicas) |
Resumo
Human respiratory syncytial virus (HRSV) is one of the most important clinical respiratory pathogens, once 64 million children between 0 and 5 years old are infected by this agent every year and can develop bronquiolits and pneumonia and eventually can cause dead. Nowadays prevention is possible through immunotherapy, however an effective vaccine is not yet available. Host immunity and viral genetic variability are important factors to develop a vaccine. Besides, viral quasispecies is another factor that complicates the vaccine production. Quasispecies are formed by dynamic between master and minority sequences distributed in an organized form inside viral population, which can work as a viral memory. Non-frequent sequences can become dominant in the presence of selective pressure. In this research HRSV quasispecies were detected in clinical samples in absence and presence of human polyclonal serum collected from children in the convalescent phase and from their mothers. HRSV samples and respective sera were firstly identified by immunofluorescence tests. Viral clones were selected by plaque assay in the absence and presence of sera. G and F genes variable region sequences of clones were compared using bioinformatics programs. A non-synonymy variation was found in the F gene in neutralization antibodies absence. Two variations were synonymous and two were non-synonymous, the last in the same nucleotide. A non-synonymy mutation was found in the G gene in presence of polyclonal serum collected from a child in convalescent phase of illness. This alteration was also observed in absence of polyclonal serum. In conclusion it is possible that minority sequences are selected by host antibodies contributing to the HRSV evolution process.
Financial support: FAPESP
Palavras-chave: human respiratory syncytial virus, Quasispecies, G protein, F protein, Human polyclonal serum |