RESUMEN
Complete nucleotide sequence of genomic RNA of hepatitis A virus (HAV) rapidly replicating strain MB-7 was determined. Comparison of nucleotide and deduced amino-acid sequences demonstrated the highest level of identity of MB-7 with strain HAS-15 (above 99%) and high homology with other HAV strains (HM 175/7, CR326, and GBM/HFS) used in production of anti-hepatitis A vaccines. MB-7 was classified as subgenotype IA. Phylogenetic analysis showed that MB-7 is most closely related to the strain HAS-15 and the HAV variants circulating in Russia. Comparative analysis of genomic differences between MB-7 and HAS-15 with other HAV strains revealed among changes characteristic of MB-7 those typical of the described earlier rapidly replicating HAV strains (nt. 149-162 in 5'-untranslated region and changes in the VP3 and 2C genes). These results suggest the functional importance of changes in above-mentioned regions of HAV genome for the increased replication level of MB-7 in vitro.
Asunto(s)
Virus de la Hepatitis A Humana/genética , Hepatitis A/virología , ARN Viral/genética , Replicación Viral , Secuencia de Bases , Virus de la Hepatitis A Humana/clasificación , Humanos , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ARN , Homología de Secuencia de Ácido Nucleico , Proteínas Virales/genéticaRESUMEN
The influence of a vaccine based on the MB-7 strain of hepatitis A virus (VP-MB-7) designed at the "Vector" Center of Virology and Biotechnology was studied. VP-MB-7 was found to provoke no allergic response and to have an activating effect on the specific and non-specific responses of cell and humoral immunity similar to those evoked by hepatitis A vaccine "Hep-A-in Vac".
Asunto(s)
Anticuerpos de Hepatitis A/biosíntesis , Vacunas contra la Hepatitis A/administración & dosificación , Vacunas contra la Hepatitis A/inmunología , Virus de la Hepatitis A Humana/inmunología , Hepatitis A/prevención & control , Vacunación , Animales , Recuento de Células , Evaluación Preclínica de Medicamentos , Cobayas , Hepatitis A/sangre , Inmunidad Celular , Recuento de Linfocitos , Ratones , Ratones Endogámicos BALB C , Bazo/inmunología , Subgrupos de Linfocitos T/inmunología , Linfocitos T Colaboradores-Inductores/inmunologíaRESUMEN
A study was undertaken to prove that a vaccine drug based on the fast-growing MB-7 (MB-7 VD) of hepatitis A virus (HAV) is safe. It was established that MB-7 VD, when once injected to white outbred mice and when 4 times injected to Hartley guineas pigs, did not cause any hematological and biochemical changes in the peripheral blood or in the condition of the central nervous system of experimental animals, which shows that MB-7 VD is free of any toxic properties.
Asunto(s)
Vacunas contra la Hepatitis A/administración & dosificación , Hepatitis A/prevención & control , Vacunación , Animales , Recuento de Células Sanguíneas , Evaluación Preclínica de Medicamentos , Eritrocitos/inmunología , Cobayas , Hemoglobinas/análisis , Hepatitis A/sangre , Hepatitis A/inmunología , Vacunas contra la Hepatitis A/inmunología , Linfocitos/inmunología , RatonesRESUMEN
Russian cultural concentrated inactivated vaccine protecting from hepatitis A--Hep-A-in-vac was used for immunization of children. The vaccine is slightly reactogenic and completely safe in children aged 3-17 years vaccinated twice in a dose of 0.25 ml. Double immunization of seronegative children with a 1-month interval led to conversion in 89.7% children. In 64.1% children titers of antibodies to hepatitis A virus reached 20 mIU/ml and higher, which indicates rather high antigenic activity of the vaccine.
Asunto(s)
Hepatitis A/prevención & control , Vacunas de Productos Inactivados/inmunología , Vacunas contra Hepatitis Viral/inmunología , Adolescente , Anticuerpos Antivirales/sangre , Niño , Preescolar , Vacunas contra la Hepatitis A , Humanos , Vacunas de Productos Inactivados/administración & dosificación , Vacunas de Productos Inactivados/uso terapéutico , Vacunas contra Hepatitis Viral/administración & dosificación , Vacunas contra Hepatitis Viral/uso terapéuticoRESUMEN
Modernization of the protocol and optimization of the technology of preparation of inactivated hepatitis A vaccine helped prepare the experimental lots of inactivated vaccine meeting all the requirements to such preparations and the WHO recommendations.
Asunto(s)
Hepatitis A/prevención & control , Hepatovirus/inmunología , Vacunas contra Hepatitis Viral/biosíntesis , Vacunas contra Hepatitis Viral/inmunología , Animales , Células Cultivadas , Chlorocebus aethiopsRESUMEN
A fast-growing cytopathic isolate of human hepatitis A virus (strain MB-7) was derived from fecal samples of infected patients and adapted to growth in FRhK-4 cell culture. A positive serum standard against HAV and electron microscopy were used to demonstrate that MB-7 belonged to human hepatitis A virus. The strain MB-7 induced plaque formation in FRhK-4 under agar overlay after 10-12 days of incubation. The PCR products of gene VP1 were cloned in E. coli and its primary structure was determined. MB-7 was shown to have more homology with HAV strains isolated in the USA and China.
Asunto(s)
Hepatovirus/aislamiento & purificación , Hepatovirus/patogenicidad , Antígenos Virales/análisis , Secuencia de Bases , Clonación Molecular , Efecto Citopatogénico Viral , ADN Complementario/genética , ADN Viral/genética , Hepatitis A/microbiología , Hepatovirus/genética , Hepatovirus/crecimiento & desarrollo , Hepatovirus/inmunología , Humanos , Microscopía Electrónica , Datos de Secuencia Molecular , Pruebas de Neutralización , Siberia , Cultivo de VirusRESUMEN
The karyological analysis of the cell line 4647 used for production of a killed vaccine to Hepatitis A virus was run in the 98th, 107th, 117th and 127th passages by the routine and C, G, and Ag methods of differential chromosome staining. A considerable balancing of the chromosome composition at 107-127 passage levels is shown. The cells of line 4647 present a significant heterogeneity, as to the number of chromosomes, and do not belong to any distinct modal class. The modal number of chromosomes ranged from 61 to 66 and from 121 to 125 for hyperdiploid and polyploid cells, respectively. The stable modal class of cells was established in the tetrasomic region, when culturing in the medium containing 10% CS from the 107th passage, and in the medium containing 10% FBS from the 117th passage, which conforms to one of the WHO requirements asserted to the substrate cells.
Asunto(s)
Riñón/ultraestructura , Animales , Línea Celular , Células Cultivadas/ultraestructura , Chlorocebus aethiops , Bandeo Cromosómico/métodos , Medios de Cultivo , Marcadores Genéticos , Hepatovirus/inmunología , Cariotipificación , Factores de Tiempo , Vacunas contra Hepatitis Viral/biosíntesisRESUMEN
Identification of 10 cell lines of 6 insect species received by the cell culture collection of Molecular Biology Institute from different research institutions of the USSR was carried out by karyological analysis and determinations of the spectrum of isoforms of the following enzymes: glucose-6-phosphate dehydrogenase (G-6-PDH), lactate dehydrogenase (LDH), isocitrate dehydrogenase (ICDH), and superoxide dismutase (SOD). Nine out of the 10 cell lines examined were shown to be identical to those of gypsy moth. Possible ways of cell contamination with other cells in long-term cultivation and preparation of new lines were determined.