title: Production of classical swine fever virus envelope glycoprotein E2 as recombinant polyhedra in baculovirus-infected silkworm larvae.
abstract: Although, classical swine fever virus (CSFV) envelope glycoprotein E2 subunit vaccine has been developed using the baculovirus expression system, the expression of viral antigens in baculovirus-infected insect cells is often ineffective. Therefore, an alternative strategy to the traditional baculovirus expression system is needed that is more productive and effective. Here, we report a novel strategy for the large-scale production of a CSFV E2 in the larvae of a baculovirus-infected silkworm, Bombyx mori. We constructed a recombinant B. mori nucleopolyhedrovirus (BmNPV) that expressed recombinant polyhedra together with the N-terminal 179 amino acids of CSFV E2 (E2ΔC). BmNPV-E2ΔC-infected silkworm larvae expressed native polyhedrin and approximately 44-kDa fusion protein that was detected using both anti-polyhedrin and anti-CSFV E2 antibodies. Electron and confocal microscopy both demonstrated that the recombinant polyhedra contained both the fusion protein and native polyhedrin were morphologically normal and contained CSFV E2ΔC. The CSFV E2ΔC antigen produced in BmNPV-E2ΔC-infected silkworm larvae reached 0.68 mg/ml of hemolymph and 0.53 mg/larva at 6-days post-infection. Six-week-old female BALB/c mice that were immunized with the E2ΔC protein purified from solubilized recombinant polyhedra elicited CSFV E2 antibodies, which indicated that the CSFV E2ΔC protein from recombinant polyhedra was immunogenic. The virus neutralization test showed that the serum from mice that were treated with E2ΔC protein from recombinant polyhedra contained significant levels of virus neutralization activity. These results demonstrate that this strategy can be used for the large-scale production of CSFV E2 antigen.
authors.affiliation: College of Natural Resources and Life Science, Dong-A University, Busan 604-714, Republic of Korea.
authors.forename: Kwang Sik
authors.initials: KS
authors.lastname: Lee
authors.forename: Mi Ri
authors.initials: MR
authors.lastname: Sohn
authors.forename: Bo Yeon
authors.initials: BY
authors.lastname: Kim
authors.forename: Young Moo
authors.initials: YM
authors.lastname: Choo
authors.forename: Soo Dong
authors.initials: SD
authors.lastname: Woo
authors.forename: Sung Sik
authors.initials: SS
authors.lastname: Yoo
authors.forename: Yeon Ho
authors.initials: YH
authors.lastname: Je
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Jong Yul
authors.initials: JY
authors.lastname: Roh
authors.forename: Hyun Na
authors.initials: HN
authors.lastname: Koo
authors.forename: Byung Rae
authors.initials: BR
authors.lastname: Jin
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000276:immunology / Q000378:metabolism; D016367:Baculoviridae / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D012831:Bombyx / Q000378:metabolism* / Q000821:virology; D005260:Female; D015967:Gene Expression Regulation, Viral; D007114:Immunization; D007814:Larva / Q000378:metabolism / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D009500:Neutralization Tests; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D014759:Viral Envelope Proteins / Q000096:biosynthesis* / Q000235:genetics; D014765:Viral Vaccines / Q000378:metabolism
chemical_list: D000956:Antigens, Viral; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C087086:glycoprotein E2, classical swine fever virus