title: Induction of immune responses in mice and pigs by oral administration of classical swine fever virus E2 protein expressed in rice calli.
abstract: Classical swine fever (CSF), caused by the CSF virus (CSFV), is a highly contagious disease in pigs. In Korea, vaccination using a live-attenuated strain (LOM strain) has been used to control the disease. However, parenteral vaccination using a live-attenuated strain still faces a number of problems related to storage, cost, injection stress, and differentiation of CSFV infected and vaccinated pigs. Therefore, two kinds of new candidates for oral vaccination have been developed based on the translation of the E2 gene of the SW03 strain, which was isolated from an outbreak of CSF in 2002 in Korea, in transgenic rice calli (TRCs) from Oriza sativa L. cv. Dongjin to express a recombinant E2 protein (rE2-TRCs). The expression of the recombinant E2 protein (rE2) in rE2-TRCs was confirmed using Northern blot, SDS-PAGE, and Western blot analysis. Immune responses to the rE2-TRC in mice and pigs were investigated after oral administration. The administration of rE2-TRCs increased E2-specific antibodies titers and antibody-secreting cells when compared to animals receiving the vector alone (p < 0.05 and p < 0.01). In addition, mice receiving rE2-TRCs had a higher level of CD8+ lymphocytes and Th1 cytokine immune responses to purified rE2 (prE2) in vitro than the controls (p < 0.05 and p < 0.01). Pigs receiving rE2-TRCs also showed an increase in IL-8, CCL2, and the CD8+ subpopulation in response to stimulation with prE2. These results suggest that oral administration of rE2-TRCs can induce E2-specific immune responses.
authors.affiliation: Department of Infectious diseases, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Korea.
authors.forename: Myunghwan
authors.initials: M
authors.lastname: Jung
authors.forename: Yun Ji
authors.initials: YJ
authors.lastname: Shin
authors.forename: Ju
authors.initials: J
authors.lastname: Kim
authors.forename: Seung-Bin
authors.initials: SB
authors.lastname: Cha
authors.forename: Won-Jung
authors.initials: WJ
authors.lastname: Lee
authors.forename: Min-Kyoung
authors.initials: MK
authors.lastname: Shin
authors.forename: Seung Won
authors.initials: SW
authors.lastname: Shin
authors.forename: Moon-Sik
authors.initials: MS
authors.lastname: Yang
authors.forename: Yong-Suk
authors.initials: YS
authors.lastname: Jang
authors.forename: Tae-Ho
authors.initials: TH
authors.lastname: Kwon
authors.forename: Han Sang
authors.initials: HS
authors.lastname: Yoo
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000921:Antibody-Producing Cells / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D018932:Chemokine CCL2 / Q000378:metabolism; D006692:Classical Swine Fever Virus / Q000235:genetics / Q000276:immunology*; D016209:Interleukin-8 / Q000378:metabolism; D007723:Korea; D051379:Mice; D012275:Oryza / Q000235:genetics*; D030821:Plants, Genetically Modified; D013552:Swine; D016176:T-Lymphocyte Subsets / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D000914:Antibodies, Viral; D018932:Chemokine CCL2; D016209:Interleukin-8; D014614:Vaccines, Synthetic; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C087086:glycoprotein E2, classical swine fever virus