RESUMEN
The aim of this work is to identify antigenic regions within the ORF1 protein of Torque teno sus virus 1 (TTSuV1) and Torque teno virus sus 2 (TTSuV2) that could be used as antigens to detect virus-specific antibodies following infection in pigs. Protein sequences of TTSuV ORF1 genes were analysed to predict linear antigenic epitopes. Synthesized peptides were analysed for serological reactivity with swine sera. Such an antigenic region was identified at the C terminus of the ORF1 protein of both viruses and showed serological reactivity with 78 % (TTSuV1) and 88 % (TTSuV2) of swine sera. An ELISA with an immunodominant peptide as antigen was used to examine the sera of piglets, aged 4-20 weeks, and adults. Results indicated that TTSuV1- and TTSuV2-specific antibodies were detectable at 4 weeks. Antibody titres increased from week 10 and peaked at week 20. A relatively high antibody titre persisted to adulthood.
Asunto(s)
Proteínas de la Cápside/química , Proteínas de la Cápside/inmunología , Infecciones por Virus ADN/veterinaria , Enfermedades de los Porcinos/inmunología , Torque teno virus/inmunología , Secuencia de Aminoácidos , Animales , Anticuerpos Antivirales/inmunología , Proteínas de la Cápside/genética , Infecciones por Virus ADN/inmunología , Infecciones por Virus ADN/virología , Mapeo Epitopo , Datos de Secuencia Molecular , Porcinos , Enfermedades de los Porcinos/virología , Torque teno virus/química , Torque teno virus/genéticaRESUMEN
Torque teno virus (TTV) is a nonenveloped virus containing a single-stranded, circular DNA genome of approximately 3.8kb. We completely synthesized the 3 808 nucleotides of the TTV (SANBAN isolate) genome, which contains a hairpin structure and a GC-rich region. More than 100 overlapping oligonucleotides were chemically synthesized and assembled by polymerase chain assembly reaction (PCA), and the synthesis was completed with splicing by overlap extension (SOEing). This study establishes the methodological basis of the chemical synthesis of a viral genome for use as a live attenuated vaccine or gene therapy vector.
Asunto(s)
ADN Viral/síntesis química , Genes Sintéticos , Genoma Viral , Reacción en Cadena de la Polimerasa/métodos , Biología Sintética/métodos , Torque teno virus/química , ADN Viral/genética , Torque teno virus/genéticaRESUMEN
TT virus (TTV) is not only an infectious agent of worldwide distribution but has also been demonstrated in various non-human primates in addition to humans. In the present study, we subjected the sera of 67 gibbons to PCR and nucleotide sequencing, with subsequent phylogenetic analysis to determine the nature of the relationship between TTV found in humans and non-human primates. We discovered the virus in 9/67 (13.4%) of the gibbon sera and subjected 6 of those to direct sequencing. The phylogenetic tree constructed encompassed all TTV species known to date, revealing a close proximity between the gibbon virus and those detected in Thai individuals, whereas the chimpanzee strains were phylogenetically more remote.
Asunto(s)
Infecciones por Virus ADN/veterinaria , Hylobates/virología , Torque teno virus/genética , Animales , Secuencia de Bases , Infecciones por Virus ADN/virología , ADN Viral/química , ADN Viral/genética , ADN Viral/aislamiento & purificación , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa/veterinaria , Alineación de Secuencia , Análisis de Secuencia de ADN , Tailandia , Torque teno virus/químicaRESUMEN
Early estimates of the prevalence of TTV viremia in healthy adults of developed countries were in the order of 1--10 %, while similar estimates in Third World countries were considerably higher. Using three different PCRs, TTV-related DNA was detected in serum from 180 out of the 201 Norwegian blood donors tested, indicating that these viruses are almost universally present in adults. Sequence analysis revealed heterogeneity similar to what is found world-wide. The data suggest that the previous discrepancy in prevalences might be related to a lower serum concentration of virus in developed countries. The high prevalence adds evidence to the benign nature of the virus.
Asunto(s)
Donantes de Sangre , ADN Viral/genética , Variación Genética , Genoma Viral , Torque teno virus/química , Torque teno virus/genética , Adolescente , Adulto , Anciano , Secuencia de Bases , ADN Viral/sangre , ADN Viral/aislamiento & purificación , Genotipo , Humanos , Persona de Mediana Edad , Noruega/epidemiología , Filogenia , Reacción en Cadena de la Polimerasa/métodos , Prevalencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Alineación de SecuenciaRESUMEN
The phylogenetic relationship between the complete genomic sequences of ten Japanese and one French isolate of TT virus-like mini virus (TLMV) was investigated. Analysis of the variability of the nucleotide sequences and the detection of signature patterns for overlapping genes suggested that ORFs 1 and 2 are probably functional. However, this was not the case for a putative third ORF, ORF3. Throughout the viral genome, several nucleotide or amino acid motifs that are conserved in circoviruses such as TT virus (TTV) and chicken anaemia virus were identified. Phylogenetic analysis distinguished three main groups of TLMV and allowed the identification of putative recombination breakpoints in the untranslated region. TLMV genomes were detected by PCR in the plasma of 38/50 French blood donors tested and were also identified in peripheral blood mononuclear cells, faeces and saliva. A phylogenetic study of 37 TLMV strains originating from France, Japan and Brazil showed that groupings were not related to geographical origin.
Asunto(s)
Circovirus/genética , Infecciones por Virus ADN/virología , Genoma Viral , Torque teno virus/genética , Composición de Base , Brasil/epidemiología , Infecciones por Circoviridae/epidemiología , Infecciones por Circoviridae/virología , Circovirus/química , Secuencia Conservada/genética , Infecciones por Virus ADN/epidemiología , ADN Viral/sangre , ADN Viral/genética , Heces/virología , Francia/epidemiología , Humanos , Japón/epidemiología , Leucocitos Mononucleares/virología , Sistemas de Lectura Abierta/genética , Filogenia , Recombinación Genética/genética , Saliva/virología , Torque teno virus/químicaRESUMEN
BACKGROUND: To investigate the prevalence of transfusion transmitted virus (TTV) and its sequence characterization in China. METHODS: TTV DNA was amplified by Semi-Nested-PCR, and the positive products were sequenced directly. RESULTS: The homology of partial nucleotide and amino acid sequences of 7 Chinese TTV isolates were 64.7%-98.4% and 62.7%-96.4% respectively when compared with Japanese isolate. Among 7 Chinese TTV isolates, the homology of partial nucleotide and amino acid sequences were 63.5%-98.4% and 60.2%-96.4% respectively. They differently belong to two genotypes and two subgenotypes. CONCLUSIONS: There exists TTV in China, and there might be several genotypes of Chinese TTV isolates.