Project description:Transmissible gastroenteritis virus (TGEV; Coronaviridae family) causes huge economic losses to the swine industry. MicroRNAs (miRNAs) play a regulatory role in viral infection and may be involved in the mammalian immune response. Here, we report a comprehensive analysis of host miRNA expression in TGEV-infected swine testis (ST) cells. Deep sequencing generated 3,704,353 and 2,763,665 reads from uninfected ST cells and infected ST cells, respectively. The reads were aligned to known Sus scrofa pre-miRNAs in miRBase 19, identifying 284 annotated miRNAs. Certain miRNAs were differentially regulated during TGEV infection, which confirmed the hypothesis that specific miRNAs play a regulatory role in virus-host interactions. 59 unique miRNAs displayed significant differentially expression between the normal and TGEV-infected ST cell samples: 15 miRNAs were significantly up-regulated and 44 were significantly down-regulated. Stem-loop RT-PCR was carried out to determine the expression levels of specific miRNAs in the two samples, and the results were consistent with those of sequencing. Gene ontology enrichment analysis of host target genes demonstrated that the differentially expressed miRNAs are involved in regulatory networks, including cellular process, metabolic process, immune system process. This is the first report of the identification of ST cell miRNAs and the comprehensive analysis of the miRNA regulatory mechanism during TGEV infection, which revealed the miRNA molecular regulatory mechanisms for the viral infection, expression of viral genes and the expression of immune-related genes. The results presented here will aid research on the prevention and treatment of viral diseases. 2 ST(Porcine testicular cells) cell samples, ST: normal ST cell sample (contro sample), TGEV: TGEV (Transmissible gastroenteritis virus) infected ST cell samples
Project description:Transmissible gastroenteritis virus (TGEV; Coronaviridae family) causes huge economic losses to the swine industry. MicroRNAs (miRNAs) play a regulatory role in viral infection and may be involved in the mammalian immune response. Here, we report a comprehensive analysis of host miRNA expression in TGEV-infected swine testis (ST) cells. Deep sequencing generated 3,704,353 and 2,763,665 reads from uninfected ST cells and infected ST cells, respectively. The reads were aligned to known Sus scrofa pre-miRNAs in miRBase 19, identifying 284 annotated miRNAs. Certain miRNAs were differentially regulated during TGEV infection, which confirmed the hypothesis that specific miRNAs play a regulatory role in virus-host interactions. 59 unique miRNAs displayed significant differentially expression between the normal and TGEV-infected ST cell samples: 15 miRNAs were significantly up-regulated and 44 were significantly down-regulated. Stem-loop RT-PCR was carried out to determine the expression levels of specific miRNAs in the two samples, and the results were consistent with those of sequencing. Gene ontology enrichment analysis of host target genes demonstrated that the differentially expressed miRNAs are involved in regulatory networks, including cellular process, metabolic process, immune system process. This is the first report of the identification of ST cell miRNAs and the comprehensive analysis of the miRNA regulatory mechanism during TGEV infection, which revealed the miRNA molecular regulatory mechanisms for the viral infection, expression of viral genes and the expression of immune-related genes. The results presented here will aid research on the prevention and treatment of viral diseases.
Project description:Porcine epidemic diarrhea virus (PEDV) is an enteric coronavirus causing high morbidity and mortality in porcine herds worldwide. Although both inactivated and live attenuated vaccines have been extensively used, the emergence of highly virulent strains and the recurrent outbreaks even in vaccinated farms highlight the need of effective vaccines. Engineering of genetically defined live attenuated vaccines is a rational approach for novel vaccine development. In this line, we engineered an attenuated virus based on the transmissible gastroenteritis virus (TGEV) genome, expressing a chimeric spike protein from a virulent United States (US) PEDV strain. This virus (rTGEV-RS-SPEDV) was attenuated in highly-sensitive five-day-old piglets, as infected animals did not lose weight and none of them died. In addition, the virus caused very minor tissue damage compared with a virulent virus. The rTGEV-RS-SPEDV vaccine candidate was also attenuated in three-week-old animals that were used to evaluate the protection conferred by this virus, compared with the protection induced by infection with a virulent PEDV US strain (PEDV-NVSL). The rTGEV-RS-SPEDV virus protected against challenge with a virulent PEDV strain, reducing challenge virus titers in jejunum and leading to undetectable challenge virus RNA levels in feces. The rTGEV-RS-SPEDV virus induced a humoral immune response specific for PEDV, including neutralizing antibodies. Altogether, the data indicated that rTGEV-RS-SPEDV is a promising vaccine candidate against virulent PEDV infection.
Project description:Transmissible gastroenteritis virus (TGEV) is a coronavirus associated with diarrhea and high mortality in piglets. To gain insight into the evolution and adaptation of TGEV, a comprehensive analysis of phylogeny and codon usage bias was performed. The phylogenetic analyses of maximum likelihood and Bayesian inference displayed two distinct genotypes: genotypes I and II, and genotype I was classified into subtypes Ia and Ib. The compositional properties revealed that the coding sequence contained a higher number of A/U nucleotides than G/C nucleotides, and that the synonymous codon third position was A/U-enriched. The principal component analysis based on the values of relative synonymous codon usage (RSCU) showed the genotype-specific codon usage patterns. The effective number of codons (ENC) indicated moderate codon usage bias in the TGEV genome. Dinucleotide analysis showed that CpA and UpG were over-represented and CpG was under-represented in the coding sequence of the TGEV genome. The analyses of Parity Rule 2 plot, ENC-plot, and neutrality plot displayed that natural selection was the dominant evolutionary driving force in shaping codon usage preference in genotypes Ia and II. In addition, natural selection played a major role, while mutation pressure had a minor role in driving the codon usage bias in genotype Ib. The codon adaptation index (CAI), relative codon deoptimization index (RCDI), and similarity index (SiD) analyses suggested that genotype I might be more adaptive to pigs than genotype II. Current findings contribute to understanding the evolution and adaptation of TGEV.
Project description:Transmissible gastroenteritis (TGE) is a highly contagious enteric disease of swine, which became infrequent with the appearance of porcine respiratory coronavirus (PRCV). TGE was last reported in Hungary in 2013 and the virus has not been found since, therefore a serological survey was planned to estimate the level of protection against it. 908 sera of sows from 93 farms were selected together with 174 archive samples from one farm covering a wider age group. All samples were screened with an indirect immunofluorescence (IF) test with a positive result of 15.42% and 17.82%, respectively. All IF-positive samples were examined with a commercial ELISA, revealing seropositivity against PRCV in almost all cases. These findings should serve as a recommendation to not omit TGE from the diagnostics of diarrhoea in swine.
Project description:To analyze the effect of Transmissible gastroenteritis virus (TGEV) infection on expression profile of circular RNAs (circRNAs) in pig renal epithelial cells (PK-15), we decided to sequence the circRNAs transcriptome of control and TGEV-infected PK-15 cells based on the Illumina HiSeq 4000 platform. The source genes of the differentially expressed circRNAs were subjected to GO function and KEGG pathway enrichment analysis. Meanwhile, we built a regulatory network of DE circRNAs and predicted multiple circRNA-miRNA-mRNA regulatory axes about innate immunity and the pathogenesis of TGEV. In this study, transcriptome sequencing results revealed that a total of 1029 novel circRNAs were identified in the control and TGEV- infected PK -15 cells. In TGEV-infected PK-15 cells, the expression levels of 70 circRNAs were significantly up-regulated and 58 circRNAs were significantly down-regulated compared to control PK-15 cells. GO functional analysis of the source genes of differentially expressed circRNAs indicated that the differentially expressed circRNAs source genes in TGEV-infected PK-15 cells were mainly enriched in the intracellular part, intracellular membrane-bounded organelle and nucleus and cellular macromolecule metabolic process, nucleobase-containing compound metabolic process, nitrogen compound metabolic process, and regulation of cellular metabolic process and heterocyclic compound binding, organic cyclic compound binding and nucleic acid binding.The results of KEGG pathway enrichment analysis showed that the significantly differentially expressed circRNAs source genes in the TGEV-infected PK -15 cells were mainly enriched in the regulation of actin cytoskeleton, influenza A, hepatitis C and cAMP signaling pathway. circRNA-miRNA-mRNA interaction networks demonstrated that circRNAs regulated innate immunity and transmembrane ion transport.