Autographa californica multiple nucleopolyhedrovirus ODV-E56 is a per os infectivity factor, but is not essential for binding and fusion of occlusion-derived virus to the host midgut

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• 作者：Wendy O. Sparks ; Robert L. Harrison ; Bryony C. Bonning
• 关键词：Occlusion-derived virus ; Per os infectivity factor ; Baculovirus ; Heliothis virescens ; ODV-e56 ; Pif-5 ; Autographa californica multiple nucleopolyhedrovirus
• 刊名：Virology
• 出版年：2011
• 出版时间：5 January 2011
• 年：2011
• 卷：409
• 期：1
• 页码：69-76
• 全文大小：913 K

文摘

The Autographa californica multiple nucleopolyhedrovirus (AcMNPV) occlusion-derived virus (ODV) envelope protein ODV-E56 is essential for oral infection of larvae of Heliothis virescens. Bioassays with recombinant clones of AcMNPV lacking a functional odv-e56 gene showed that ODV-E56 was required for infectivity of both polyhedra and to a lesser extent, purified ODV. However, binding and fusion assays showed that ODV lacking ODV-E56 bound and fused to midgut cells at levels similar to ODV of wild-type virus. Fluorescence microscopy of midguts from larvae inoculated with ODV-E56-positive and -negative viruses that express GFP indicated that ODV-E56 was required for infection of the midgut epithelium. Purified ODV-E56 bound to several proteins in midgut-derived brush border membrane vesicles, but failed to rescue infectivity of ODV-E56-negative viruses in trans. These results indicate that ODV-E56 is a per os infectivity factor (pif-5) required for primary midgut infection at a point before or after virion binding and fusion.