Potent virucidal activity in larval Heliothis virescens plasma against Helicoverpa zea single capsid nucleopolyhedrovirus

Lepidopteran larvae resist baculovirus infection by selective apoptosis of infected midgut epithelial cells and by sloughing off infected cells from the midgut. Once the infection breaches the midgut epithelial barrier and propagates from infective foci to the haemocoel, however, there are few mecha...

Full description

Saved in:
Bibliographic Details
Published in:Journal of general virology 2004-08, Vol.85 (8), p.2255-2261
Main Authors: Popham, H.J.R, Shelby, K.S, Brandt, S.L, Coudron, T.A
Format: Article
Language:English
Subjects:
Animals
Baculovirus
Biological and medical sciences
Endopeptidase K - pharmacology
Fundamental and applied biological sciences. Psychology
Helicoverpa zea
Helicoverpa zea single nucleopolyhedrovirus
Heliothis virescens
Larva - immunology
Larva - virology
Microbiology
Miscellaneous
Monophenol Monooxygenase - physiology
Moths - immunology
Moths - virology
Nucleopolyhedroviruses - growth & development
Virology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Lepidopteran larvae resist baculovirus infection by selective apoptosis of infected midgut epithelial cells and by sloughing off infected cells from the midgut. Once the infection breaches the midgut epithelial barrier and propagates from infective foci to the haemocoel, however, there are few mechanisms known to account for the resistance and clearance of infection observed in some virus-host combinations. The hypothesis that factors present in the plasma of infected pest larvae act to limit the spread of virus from initial infective foci within the haemocoel was tested. An in vitro bioassay was developed in which Helicoverpa zea single capsid nucleopolyhedrovirus (HzSNPV) was incubated with plasma collected from uninfected Heliothis virescens larvae. Infectious HzSNPV particles were then titrated on HzAM1 cells. Diluted plasma from larval Heliothis virescens exhibited a virucidal effect against HzSNPV in vitro, reducing the TCID50 ml-1 by more than 64-fold (from 4·3±3·6x10(5) to 6·7±0·6x10(3)). The antiviral activity was heat-labile but was unaffected by freezing. In addition, protease inhibitors and specific chemical inhibitors of phenol oxidase or prophenol oxidase activation added to diluted plasma eliminated the virucidal activity. Thus, in the plasma of larval lepidopterans, the enzyme phenol oxidase may act as a constitutive, humoral innate antiviral immune response.
ISSN:0022-1317
1465-2099
DOI:10.1099/vir.0.79965-0