Early Synthesis of Budded Virus Envelope Fusion Protein GP64 Enhances Autographa californica Multicapsid Nucleopolyhedrovirus Virulence in Orally Infected Heliothis virescens
AUTOR(ES)
Washburn, Jan O.
FONTE
American Society for Microbiology
RESUMO
Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV), the type species of the Nucleopolyhedrovirus genus (Baculoviridae family), has two highly unusual traits shared by several baculovirus species. First, the occlusion-derived virus (ODV) that establishes primary infection in the midgut following its ingestion by host larvae contains multiple nucleocapsids, all of which enter the same midgut cell. Second, GP64, the envelope fusion protein of the budded virus (BV) that spreads infection beyond the midgut, is synthesized both early and late during infection. We tested the hypothesis that, together, these two traits enable parental ODV nucleocapsids to bud from infected midgut cells, essentially as BV, to establish secondary infections prior to completion of viral replication within the midgut. This “pass-through” strategy would enable the virus to counter the host's principal defense, sloughing of infected midgut cells, by accelerating the onset of systemic infections. To test this hypothesis, we created an AcMNPV recombinant, AcLate21/20-64HB, that can express gp64 only during the late phase of infection (coincident with the other structural proteins). We then compared the virulence of this virus to that of a control recombinant virus that expresses gp64 in a wild-type manner. We found that when administered orally, the control virus was far more virulent and established secondary infection earlier than AcLate21/20-64HB, but when administered intrahemocoelically, infectivity and virulence of the two recombinants were identical. Our results demonstrate that early gp64 expression is a key component of a unique and highly adaptive baculovirus infection strategy.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=140599Documentos Relacionados
- The Pre-Transmembrane Domain of the Autographa californica Multicapsid Nucleopolyhedrovirus GP64 Protein Is Critical for Membrane Fusion and Virus Infectivity▿ †
- Palmitoylation of the Autographa californica Multicapsid Nucleopolyhedrovirus Envelope Glycoprotein GP64: Mapping, Functional Studies, and Lipid Rafts
- Mutational Analysis of the N-Linked Glycans on Autographa californica Nucleopolyhedrovirus gp64
- Pseudotyping Autographa californica Multicapsid Nucleopolyhedrovirus (AcMNPV): F Proteins from Group II NPVs Are Functionally Analogous to AcMNPV GP64
- Ac23, an Envelope Fusion Protein Homolog in the Baculovirus Autographa californica Multicapsid Nucleopolyhedrovirus, Is a Viral Pathogenicity Factor