Phenoloxidase Activity Acts as a Mosquito Innate Immune Response against Infection with Semliki Forest Virus
Autor(es): Rodriguez-Andres, Julio; Rani, Seema; Varjak, Margus; Chase-Topping, Margo E.; Beck, Markus H.; Ferguson, Mhairi C.; Schnettler, Esther; Fragkoudis, Rennos; Barry, Gerald; Merits, Andres; Fazakerley, John K.; Strand, Michael R.; Kohl, Alain
Resumo: Several components of the mosquito immune system including the RNA interference (RNAi), JAK/STAT, Toll and IMD pathways have previously been implicated in controlling arbovirus infections. In contrast, the role of the phenoloxidase (PO) cascade in mosquito antiviral immunity is unknown. Here we show that conditioned medium from the Aedes albopictus-derived U4.4 cell line contains a functional PO cascade, which is activated by the bacterium Escherichia coli and the arbovirus Semliki Forest virus (SFV) (Togaviridae; Alphavirus). Production of recombinant SFV expressing the PO cascade inhibitor Egf1.0 blocked PO activity in U4.4 cell-conditioned medium, which resulted in enhanced spread of SFV. Infection of adult female Aedes aegypti by feeding mosquitoes a bloodmeal containing Egf1.0-expressing SFV increased virus replication and mosquito mortality. Collectively, these results suggest the PO cascade of mosquitoes plays an important role in immune defence against arboviruses.
Palavras-Chave: Disease vector mosquitos; Aedes aegypti; RNA interference; Sindbis virus; Manduca sexta; Culex quinquefasciatus; Anopheles gambiae; Alphavirus replication; Melanization reaction; Arbovirus infection
Imprenta: Plos Pathogens, v. 8, n. 11, 2012
Identificador do objeto digital: 10.1371/journal.ppat.1002977
Descritores: Aedes aegypti - Arbovirus ; Aedes aegypti - Biochemistry ; Aedes aegypti - Cell ; Aedes aegypti - Immune response ; Aedes aegypti - Molecular structure ; Aedes aegypti - RNA ; Aedes aegypti - Immunology ; Aedes aegypti - Viral infections ; Aedes aegypti - Virus
Data de publicação: 2012
