PASSIVE IMMUNITY TO WHITE SPOT SYNDROME VIRUS (WSSV) IN PENAEUS MONODON TREATED WITH MONOCLONAL ANTIBODIES OF THE HETEROLOGOUSLY PRODUCED VP28 VIRAL ENVELOPE PROTEIN

ABSTRACT Our aim was to isolate and characterize white spot syndrome virus (WSSV)-binding proteins from shrimp. After a blot of shrimp hemocyte membrane proteins was overlaid with a recombinant WSSV envelope protein (rVP28), the reactive bands on the blot were detected using anti-VP28 antibody. Among three membrane-associated molecules identified by liquid chromatography-tandem mass spectrometry, there was a 25-kDa protein that bound to both rVP28 and WSSV. Since it had a primary structure with high homology to the small GTP-binding protein Rab7, we named it Penaeus monodon Rab7 (PmRab7). The full-length PmRab7 cDNA was obtained, and results from a glutathione S-transferase pull-down assay confirmed specific binding to rVP28. Reverse transcriptase PCR analysis revealed PmRab7 expression in many tissues, and real-time PCR analysis revealed that expression was constitutive. Binding of PmRab7 to rVP28 or WSSV occurred in a dose-dependent manner and was inhibited by anti-Rab7 antibody. In an in vivo neutralization assay, the number of dead shrimp after challenge with WSSV plus PmRab7 (15%) or WSSV plus anti-Rab7 antibody (5%) was significantly lower than after challenge with WSSV alone (95%). In contrast to the WSSV-injected group, shrimp injected with WSSV plus PmRab7 or WSSV plus anti-Rab7 showed no WSSV-type histopathology. We conclude that PmRab7 is involved in WSSV infection in shrimp. This is the first study to identify a shrimp protein that binds directly to a major viral envelope protein of WSSV.

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VP26 of White Spot Syndrome Virus Functions as a Linker Protein between the Envelope and Nucleocapsid of Virions by Binding with VP51

Journal of Virology ◽

10.1128/jvi.01732-08 ◽

2008 ◽

Vol 82 (24) ◽

pp. 12598-12601 ◽

Cited By ~ 29

Author(s):

Qiang Wan ◽

Limei Xu ◽

Feng Yang

Keyword(s):

Envelope Protein ◽

White Spot Syndrome Virus ◽

Direct Interaction ◽

Viral Envelope ◽

White Spot ◽

Viral Capsid ◽

Key Factor ◽

White Spot Syndrome ◽

Viral Nucleocapsid ◽

Biotin Label

ABSTRACT The envelopment of the nucleocapsid is an important step in white spot syndrome virus (WSSV) assembly. Previous studies showed that VP26, a major envelope protein of WSSV, can interact with viral nucleocapsid. In this study, using the biotin label transfer technique, we found that the biotin label was transferred from Bio-rVP26 to the viral capsid protein VP51 or from Bio-MBP-VP51 to VP26. Far-Western analyses provided further evidence for direct interaction between VP26 and VP51. Therefore, we conclude that VP26 functions as a matrix-like linker protein between the viral envelope and nucleocapsid, which suggests that VP26 is a key factor in the envelopment of WSSV virion.

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VP24 Is a Chitin-Binding Protein Involved in White Spot Syndrome Virus Infection

Journal of Virology ◽

10.1128/jvi.02357-15 ◽

2015 ◽

Vol 90 (2) ◽

pp. 842-850 ◽

Cited By ~ 17

Author(s):

Zaipeng Li ◽

Fang Li ◽

Yali Han ◽

Limei Xu ◽

Feng Yang

Keyword(s):

Amino Acids ◽

Digestive Tract ◽

Envelope Protein ◽

White Spot Syndrome Virus ◽

Viral Envelope ◽

White Spot ◽

Viral Envelope Protein ◽

Virus Particles ◽

C Terminus ◽

Shrimp Farms

ABSTRACTOral ingestion is the major route of infection for the white spot syndrome virus (WSSV). However, the mechanism by which virus particles in the digestive tract invade host cells is unknown. In the present study, we demonstrate that WSSV virions can bind to chitin through one of the major envelope proteins (VP24). Mutagenesis analysis indicated that amino acids (aa) 186 to 200 in the C terminus of VP24 were required for chitin binding. Moreover, the P-VP24186–200peptide derived from the VP24 chitin binding region significantly inhibited the VP24-chitin interaction and the WSSV-chitin interaction, implying that VP24 participates in WSSV binding to chitin. Oral inoculation experiments showed that P-VP24186–200treatment reduced the number of virus particles remaining in the digestive tract during the early stage of infection and greatly hindered WSSV proliferation in shrimp. These data indicate that binding of WSSV to chitin through the viral envelope protein VP24 is essential for WSSVper osinfection and provide new ideas for preventing WSSV infection in shrimp farms.IMPORTANCEIn this study, we show that WSSV can bind to chitin through the envelope protein VP24. The chitin-binding domain of VP24 maps to amino acids 186 to 200 in the C terminus. Binding of WSSV to chitin through the viral envelope protein VP24 is essential for WSSVper osinfection. These findings not only extend our knowledge of WSSV infection but also provide new insights into strategies to prevent WSSV infection in shrimp farms.

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