Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/10/23 17:09:23」(JST)

wiki en

Transmissible Gastroenteritis Coronavirus (TGEV) is a virus belonging to the family Coronaviridae, genus Alphacoronavirus, species Alphacoronavirus 1.^[1] TGEV are enveloped viruses with a positive-sense single-stranded RNA genome and a helical symmetry. The genomic size of coronaviruses ranges from approximately 28.6 kilobases.^[2]

Proteins that contribute to the overall structure of TGEV includes the spike (S), envelope (E), membrane (M) and nucleocapsid (N). Other coronaviruses belonging to Alphacoronavirus 1 species include Feline coronavirus, Canine coronavirus and Feline infectious peritonitis virus.

TGEV Biology

TGEV belongs to the coronaviridae family, genus Alphacoronavirus, species Alphacoronavirus 1. It is an enveloped virus with a positive single stranded RNA genome. TGEV has three major structural proteins, which are phosphoprotein (N), integral membrane protein (E1), and large glycoprotein (E2). The N protein encapsulates the genomic RNA, and the S protein forms viral projections.

The 3' segment of about 8000 nucleotides encodes subgenomic RNAs. The remaining part of the genome encodes viral replicase. The three largest gene sequence from 5' to 3' is in the order of E2 to E1 to N. There are about seven other open reading frames that are not structurally related. There are very little overlaps among the genes, and is densely packed. A negative strand is synthesized to serve as a template for transcribing RNAs of one genome size and several subgenome sized RNAs.

The E2 protein forms a petal-shaped 20 nm long projection from the virus's surface. The E2 protein is thought to be involved in pathogenesis by helping the virus enter the host cytoplasm. The E2 protein initially has 1447residues, and then a short hydrophobic sequence is cleaved. After glycosylation of the protein in the golgi, the protein is then incorporated into the new virus. There are several functional domains within the E2 protein. A 20 residue hydrophobic segment at the C-terminus anchors the protein in the lipid membrane. The rest of the protein is divided into two parts, a hydrophilic stretch that is inside the virus and a cysteine rich stretch that are possibly fatty acylation sites. The E1 protein is mostly embedded in the lipid envelop and hence plays an essential role in virus architecture. The E1 protein is postulated to interact with the lymphocyte membrane, which leads to the induction of IFN-coding genes.

TGEV Morphology

The morphology of TGEV was mostly determined by electron microscopy techniques. The morphology is similar to myxovirus and oncogenic virus in that they have surface projections and an envelop. The viruses are mainly circular in shape with a diameter ranging from 100 to 150 nm including the surface projections. The projections were mainly petal-shaped attached by a very narrow stalk. The projections seemed to be very easily detached from the virus and were only found on select areas.

TGEV pathology

TGEV infects both pigs and humans. However, in young pigs, the mortality rate is close to 100%. The pathology of TGEV is similar to that of other coronaviruses. Coronaviruses enter the host by first attaching to the host cell using the spike glycoprotein. The S protein interacts with the porcine aminopeptidase N (pAPN), a cellular receptor, to aide in its entry. The same cell receptor is also a point of contact for Human Coronaviruses. A domain in the S spike protein is recognized by pAPN, and transfection of pAPN occurs to nonpermissive cells and infects them with TGEV. Once the virus infects the host, it multiplies in the cell lining of the small intestine resulting in the loss of absorptive cells that in turn leads to shortening of villi. The infected swine then has reduced capability for digesting food and die from dehydration.

Engineering TGEV coronavirus

The Transmissible Gastroenteritis Virus has been engineered as an expression vector. The vector was constructed by replacing the nonessential 3a and 3b ORF, which is driven by the transcription-regulating sequences (TRS) with green fluorescent protein. The resulting construct was still enteropathogenic, but with reduced growth. The infection of cells with this altered virus elicits a specific lactogenic immune response against the heterologous protein. The application of this vector is in the development of a vaccine or even gene therapy. The motivation for engineering the TGEV genome is that coronaviruses have large genomes, so they have room for insertion of foreign genes. Coronaviruses also infect the respiratory tract, and they can be used to target antigens to that area and generate some immune response.

References

^ "ICTV Taxonomy History for Alphacoronavirus 1". ICTV. Retrieved 5 July 2014.
^ Thiel V, ed. (2007). Coronaviruses: Molecular and Cellular Biology (1st ed.). Caister Academic Press. ISBN 978-1-904455-16-5. ^{[page needed]}

External links

Laude H, Rasschaert D, Delmas B, Godet M, Gelfi J, Charley B (June 1990). "Molecular biology of transmissible gastroenteritis virus". Veterinary Microbiology 23 (1–4): 147–54. doi:10.1016/0378-1135(90)90144-K. PMID 2169670.
Sola I, Alonso S, Zúñiga S, Balasch M, Plana-Durán J, Enjuanes L (April 2003). "Engineering the Transmissible Gastroenteritis Virus Genome as an Expression Vector Inducing Lactogenic Immunity". Journal of Virology 77 (7): 4357–69. doi:10.1128/JVI.77.7.4357-4369.2003. PMC 150661. PMID 12634392.
Tajima M (March 1970). "Morphology of transmissible gastroenteritis virus of pigs". Archives of Virology 29 (1): 105–8. doi:10.1007/BF01253886. PMID 4195092.

English Journal

Construction of an oral vaccine for transmissible gastroenteritis virus based on the TGEV N gene expressed in an attenuated Salmonella typhimurium vector.

Zhang D1, Huang X2, Zhang X1, Cao S3, Wen X3, Wen Y3, Wu R3, Liang E1.
Journal of virological methods.J Virol Methods.2016 Jan;227:6-13. doi: 10.1016/j.jviromet.2015.08.011. Epub 2015 Aug 20.
This research aimed to develop an oral vaccine for transmissible gastroenteritis virus (TGEV) based on the TGEV N gene expressed in an attenuated Salmonella typhimurium vector and aimed to evaluate the vaccine's immune response in piglets. Recombinant plasmid pVAX-N was transformed into competent ce
PMID 26297958

(+)-Catechin inhibition of transmissible gastroenteritis coronavirus in swine testicular cells is involved its antioxidation.

Liang W1, He L2, Ning P1, Lin J1, Li H1, Lin Z1, Kang K1, Zhang Y3.
Research in veterinary science.Res Vet Sci.2015 Dec;103:28-33. doi: 10.1016/j.rvsc.2015.09.009. Epub 2015 Sep 12.
Transmissible gastroenteritis virus (TGEV) causes transmissible gastroenteritis (TGE), especially in newborn piglets, which severely threatens the worldwide pig industry. In this study, (+)-catechin was evaluated for its antiviral effect against TGEV in vitro. Viability assays revealed that (+)-cate
PMID 26679792

Development of an indirect ELISA, blocking ELISA, fluorescent microsphere immunoassay and fluorescent focus neutralization assay for serologic evaluation of exposure to North American strains of Porcine Epidemic Diarrhea Virus.

Okda F1,2, Liu X3, Singrey A4, Clement T5, Nelson J6, Christopher-Hennings J7, Nelson EA8, Lawson S9.
BMC veterinary research.BMC Vet Res.2015 Aug 1;11:180. doi: 10.1186/s12917-015-0500-z.
BACKGROUND: Recent, severe outbreaks of porcine epidemic diarrhea virus (PEDV) in Asia and North America highlight the need for well-validated diagnostic tests for the identification of PEDV infected animals and evaluation of their immune status to this virus. PEDV was first detected in the U.S. in
PMID 26232106

Japanese Journal

Prevalence of Antibodies against Transmissible Gastroenteritis Virus and Porcine Respiratory Coronavirus among Pigs in Six Regions in Japan

MIYAZAKI Ayako,FUKUDA Masaharu,KUGA Kazufumi,TAKAGI Michihiro,TSUNEMITSU Hiroshi
Journal of Veterinary Medical Science advpub(0), 1002250171, 2010
… A total of 2,703 pig sera from 171 farms in six regions in Japan were screened for virus neutralizing (VN) antibody against transmissible gastroenteritis virus (TGEV). … Although none of the farms had clinical signs of transmissible gastroenteritis (TGE) or vaccination against TGEV, VN antibody was detected in 14.4% of sera at 30 farms (17.5%) across all six regions. …
NAID 130000264266

北海道に生息するアライグマにおけるコロナウイルス感染

石原涼子,畠間真一,内田郁夫,的場洋平,浅川満彦,菅野徹
Japanese journal of zoo and wildlife medicine 14(2), 107-109, 2009-09
… 血清379検体中,1型の伝染性胃腸炎ウイルス(TGEV)および犬コロナウイルス(CCoV)に対してそれぞれ11および5検体が中和抗体陽性を示した。 …
NAID 110007465854

Related Pictures

★リンクテーブル★

リンク元	「伝染性胃腸炎ウイルス」「transmissible gastroenteritis virus」
関連記事	「TG」

「伝染性胃腸炎ウイルス」

Transmissible Gastroenteritis Coronavirus
	Canine coronavirus (the same species as TGEV) antigen in canine lung tissue
Virus classification
Group:	Group IV ((+)ssRNA)
Order:	Nidovirales
Family:	Coronaviridae
Subfamily:	Coronavirinae
Genus:	Alphacoronavirus
Species:	Alphacoronavirus 1
Subspecies:	Transmissible Gastroenteritis Coronavirus