title: Construction of a bivalent DNA vaccine co-expressing S genes of transmissible gastroenteritis virus and porcine epidemic diarrhea virus delivered by attenuated Salmonella typhimurium.
abstract: Porcine transmissible gastroenteritis virus (TGEV) and porcine epidemic diarrhea virus (PEDV) can cause severe diarrhea in newborn piglets and led to significant economic losses. The S proteins are the main structural proteins of PEDV and TGEV capable of inducing neutralizing antibodies in vivo. In this study, a DNA vaccine SL7207 (pVAXD-PS1-TS) co-expressing S proteins of TGEV and PEDV delivered by attenuated Salmonella typhimurium was constructed and its immunogenicity in piglets was investigated. Twenty-day-old piglets were orally immunized with SL7207 (pVAXD-PS1-TS) at a dosage of 1.6 × 10(11) CFU per piglet and then booster immunized with 2.0 × 10(11) CFU after 2 weeks. Humoral immune responses, as reflected by virus neutralizing antibodies and specific IgG and sIgA, and cellular immune responses, as reflected by IFN-γ, IL-4, and lymphocyte proliferation, were evaluated. SL7207 (pVAXD-PS1-TS) simultaneously elicited immune responses against TGEV and PEDV after oral immunization. The immune levels started to increase at 2 weeks after immunization and increased to levels statistically significantly different than controls at 4 weeks post-immunization, peaking at 6 weeks and declined at 8 weeks. The humoral, mucosal, and cellular immune responses induced by SL7207 (pAXD-PS1-TS) were significantly higher than those of the PBS and SL7207 (pVAXD) (p < 0.01). In particular, the levels of IFN-γ and IL-4 were higher than those induced by the single-gene vaccine SL7207 (pVAXD-PS1) (p < 0.05). These results demonstrated that SL7207 (pVAXD-PS1-TS) possess the immunological functions of the two S proteins of TGEV and PEDV, indicating that SL7207 (pVAXD-PS1-TS) is a candidate oral vaccine for TGE and PED.
authors.affiliation: Research Center of Swine Disease and Laboratory of Animal Infectious Disease and Microarray, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.
authors.forename: Yudi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Research Center of Swine Disease and Laboratory of Animal Infectious Disease and Microarray, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Research Center of Swine Disease and Laboratory of Animal Infectious Disease and Microarray, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Liao
authors.affiliation: Research Center of Swine Disease and Laboratory of Animal Infectious Disease and Microarray, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China. rsghb110@126.com.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Huang
authors.affiliation: Research Center of Swine Disease and Laboratory of Animal Infectious Disease and Microarray, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.
authors.forename: Sanjie
authors.initials: S
authors.lastname: Cao
authors.affiliation: Research Center of Swine Disease and Laboratory of Animal Infectious Disease and Microarray, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.
authors.forename: Xintian
authors.initials: X
authors.lastname: Wen
authors.affiliation: Research Center of Swine Disease and Laboratory of Animal Infectious Disease and Microarray, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Research Center of Swine Disease and Laboratory of Animal Infectious Disease and Microarray, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wu
authors.affiliation: College of Environmental Sciences, Sichuan Agricultural University, Chengdu, 611130, China.
authors.forename: Wumei
authors.initials: W
authors.lastname: Liu
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D019556:COS Cells; D004274:DNA, Recombinant / Q000235:genetics / Q000276:immunology; D004279:DNA, Viral / Q000235:genetics / Q000276:immunology; D005761:Gastroenteritis, Transmissible, of Swine / Q000276:immunology / Q000517:prevention & control; D005814:Genes, Viral; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D053485:Porcine epidemic diarrhea virus / Q000235:genetics / Q000276:immunology*; D012486:Salmonella typhimurium / Q000235:genetics* / Q000276:immunology*; D013552:Swine; D005760:Transmissible gastroenteritis virus / Q000235:genetics / Q000276:immunology*; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D004274:DNA, Recombinant; D004279:DNA, Viral; D007074:Immunoglobulin G; D014613:Vaccines, Attenuated; D019444:Vaccines, DNA; D014764:Viral Proteins; D014765:Viral Vaccines; C064484:spike protein S, Transmissible gastroenteritis virus; D015847:Interleukin-4; D007371:Interferon-gamma
keywords: Attenuated Salmonella typhimurium; Oral immunogenicity; Piglets; Porcine epidemic diarrhea; S protein; Transmissible gastroenteritis