VP2-serotyped live-attenuated bluetongue virus without NS3/NS3a expression provides serotype-specific protection and enables DIVA

Femke Feenstra; Mieke Maris-Veldhuis; Franz J Daus; Mirriam G J Tacken; Rob J M Moormann; René G P van Gennip; Piet A van Rijn

doi:10.1016/j.vaccine.2014.10.033

VP2-serotyped live-attenuated bluetongue virus without NS3/NS3a expression provides serotype-specific protection and enables DIVA

Vaccine. 2014 Dec 12;32(52):7108-14. doi: 10.1016/j.vaccine.2014.10.033. Epub 2014 Oct 31.

Authors

Femke Feenstra¹, Mieke Maris-Veldhuis², Franz J Daus², Mirriam G J Tacken², Rob J M Moormann³, René G P van Gennip², Piet A van Rijn⁴

Affiliations

¹ Central Veterinary Institute of Wageningen UR (CVI), Department of Virology, P.O. Box 65, 8200 AB, Lelystad, The Netherlands; Department of Infectious Diseases & Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. Electronic address: femke2.feenstra@wur.nl.
² Central Veterinary Institute of Wageningen UR (CVI), Department of Virology, P.O. Box 65, 8200 AB, Lelystad, The Netherlands.
³ Central Veterinary Institute of Wageningen UR (CVI), Department of Virology, P.O. Box 65, 8200 AB, Lelystad, The Netherlands; Department of Infectious Diseases & Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
⁴ Central Veterinary Institute of Wageningen UR (CVI), Department of Virology, P.O. Box 65, 8200 AB, Lelystad, The Netherlands; Department of Biochemistry, Centre for Human Metabonomics, North-West University, South Africa.

PMID: 25454873
DOI: 10.1016/j.vaccine.2014.10.033

Abstract

Bluetongue virus (BTV) causes Bluetongue in ruminants and is transmitted by Culicoides biting midges. Vaccination is the most effective measure to control vector borne diseases; however, there are 26 known BTV serotypes showing little cross protection. The BTV serotype is mainly determined by genome segment 2 encoding the VP2 protein. Currently, inactivated and live-attenuated Bluetongue vaccines are available for a limited number of serotypes, but each of these have their specific disadvantages, including the inability to differentiate infected from vaccinated animals (DIVA). BTV non-structural proteins NS3 and NS3a are not essential for virus replication in vitro, but are important for cytopathogenic effect in mammalian cells and for virus release from insect cells in vitro. Recently, we have shown that virulent BTV8 without NS3/NS3a is non-virulent and viremia in sheep is strongly reduced, whereas local in vivo replication leads to seroconversion. Live-attenuated BTV6 without NS3/NS3a expression protected sheep against BTV challenge. Altogether, NS3/NS3a knockout BTV6 is a promising vaccine candidate and has been named Disabled Infectious Single Animal (DISA) vaccine. Here, we show serotype-specific protection in sheep by DISA vaccine in which only genome segment 2 of serotype 8 was exchanged. Similarly, DISA vaccines against other serotypes could be developed, by exchange of only segment 2, and could therefore safely be combined in multi-serotype cocktail vaccines with respect to reassortment between vaccine viruses. Additionally, NS3 antibody responses are raised after natural BTV infection and NS3-based ELISAs are therefore appropriate tools for DIVA testing accompanying the DISA vaccine. To enable DIVA, we developed an experimental NS3 ELISA. Indeed, vaccinated sheep remained negative for NS3 antibodies, whereas seroconversion for NS3 antibodies was associated with viremia after heterologous BTV challenge.

Keywords: Bluetongue virus; DISA vaccine; DIVA; NS3; Reverse genetics; Serotype.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Antibodies, Viral / blood
Bluetongue virus / genetics
Bluetongue virus / immunology*
Capsid Proteins / genetics
Capsid Proteins / immunology*
Enzyme-Linked Immunosorbent Assay
Gene Knockout Techniques*
Reverse Genetics
Serogroup
Sheep
Vaccines, Attenuated / administration & dosage
Vaccines, Attenuated / genetics
Vaccines, Attenuated / immunology
Vaccines, Marker / administration & dosage
Vaccines, Marker / immunology
Viral Nonstructural Proteins / genetics*
Viral Nonstructural Proteins / immunology
Viral Vaccines / administration & dosage
Viral Vaccines / genetics
Viral Vaccines / immunology*

Substances

Antibodies, Viral
Capsid Proteins
S10 protein, Bluetongue virus
VP2 protein, Bluetongue virus
Vaccines, Attenuated
Vaccines, Marker
Viral Nonstructural Proteins
Viral Vaccines