9 research outputs found

    Pola Produksiajmalisin Darikultur Agregat Sel Catharanthus Roseus (L) G Don. Dalam Bioreaktor [Production Pattern of Ajmalicine in Catharanthus Roseus (L) G Don. Cell Aggregates Culture in the Bioreactor]

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    A research has been conducted to optimize the rate of aeration and initial cell aggregates weight in the production of ajmalicine in Catharanthus roseus cell culture in bioreactor. Catharanthus roseus culture were grown in Zenk medium with the addition of 2.5 x 10"6 M NAA ('naphthalene acetic acid') and 10s M BAP ('benzyl amino purine'). Cell aggregates were subcultured two times before transferring 20 and 30 g/fw of cell aggregates into bioreactor, respectively, and aerated with the rate of 0.2460 L/min and 0,3405 L/min, respectively. The pattern of ajmalicine production in bioreactor were observed every 3 days for 24 days.Qualitative and quantitative analysis were conducted using HPLC connected to Cromatopac CL-7APlus. The results showed that the cell aggregates and medium contain ajmalicine. The highest concentration was obtained in combination of 30 g/fw and 0.3405 L/min aeration compare to 20 g/fw - 0,246 L/min, 20 g/fw- 0,3405 L/min, as well as 30 g/fw - 0,2460 L/min. The highest ajmalicine content in cell aggregates was obtained on the 12"d days (79.23ug/g) whilst in medium was obtained in the 18th days (981.15 ug/L)

    POLA PRODUKSI AJMALISIN DARIKULTUR AGREGAT SEL Catharanthus roseus (L) G Don. DALAM BIOREAKTOR

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    A research has been conducted to optimize the rate of aeration and initial cell aggregates weight in the production of ajmalicine in Catharanthus roseus cell culture in bioreactor. Catharanthus roseus culture were grown in Zenk medium with the addition of 2.5 x 10"6 M NAA ('naphthalene acetic acid') and 10s M BAP ('benzyl amino purine'). Cell aggregates were subcultured two times before transferring 20 and 30 g/fw of cell aggregates into bioreactor, respectively, and aerated with the rate of 0.2460 L/min and 0,3405 L/min, respectively. The pattern of ajmalicine production in bioreactor were observed every 3 days for 24 days.Qualitative and quantitative analysis were conducted using HPLC connected to Cromatopac CL-7APlus. The results showed that the cell aggregates and medium contain ajmalicine. The highest concentration was obtained in combination of 30 g/fw and 0.3405 L/min aeration compare to 20 g/fw - 0,246 L/min, 20 g/fw- 0,3405 L/min, as well as 30 g/fw - 0,2460 L/min. The highest ajmalicine content in cell aggregates was obtained on the 12"d days (79.23ug/g) whilst in medium was obtained in the 18th days (981.15 ug/L)

    Evaluation of alum-based adjuvant on the immunogenicity of salmonella enterica serovar typhi conjugates vaccines

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    The function of adjuvant in maintaining the long-term immune response to Typhoid conjugate vaccine (TCV) was evaluated in. Two TCV products, Vi-DT and Vi-TT, were formulated in either aluminum phosphate (AlPO4) or aluminum hydroxide (AlOH) as adjuvants and TCV formulated in phosphate buffer saline were used as controls. In each case, a group of Balb/c mice was injected intramuscularly with two doses of the formulated vaccine at two-week intervals. The anti-Vi IgG responses were monitored by Enzyme-Linked Immunosorbent Assay and the levels of CD4+ T-cells expressing cytokine were characterized using intracellular cytokine staining. All mice immunized by TCV formulated in adjuvant elicited anti-Vi response to a higher level than the group receiving TCV formulated in PBS. The extent of adsorption of TCV in AlOH was greater than that in AlPO4, and this finding correlated well with the observation that the mice immunized with two doses of Vi-DT(AlOH) elicited anti-Vi IgG to a level higher than that seen with Vi-DT(AlPO4). The mice primed with Vi-TT(AlOH) produced lower anti-Vi IgG (25.901 GM) compared to those receiving Vi-TT(AlPO4) (49.219 GM). However, after the second injection, the former raised the antibody level significantly to 137.008 GM while the latter provided a value of only 104.966 GM. The groups of mice vaccinated by TCV formulated in AlOH expressed IL4 at higher levels than the other groups, which correlated positively with the high Anti-Vi IgG in these animals. In conclusion, AlOH could be recommended as an effective adjuvant for TCV to provide a long-term immune response

    Improvement of the qmosRT-PCR Assay and Its Application for the Detection and Quantitation of the Three Serotypes of the Novel Oral Polio Vaccine in Stool Samples

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    Recently, genetically stable novel OPVs (nOPV) were developed by modifying the genomes of Sabin viruses of conventional OPVs to reduce the risk of reversion to neurovirulence and therefore the risk of generating circulating vaccine-derived polioviruses. There is a need for specific and sensitive methods for the identification and quantification of nOPV viruses individually and in mixtures for clinical trials and potentially for manufacturing quality control and environmental surveillance. In this communication, we evaluated and improved the quantitative multiplex one-step reverse transcriptase polymerase chain reaction (qmosRT-PCR) assay for the identification and quantification of nOPV viruses in samples with different formulations and virus concentrations and in virus-spiked stool samples. The assay was able to specifically identify at least 1 log10 CCID50/mL of each serotype in the presence of the two other serotypes at high concentrations (6–7 log10 CCID50/mL) in the same sample. In addition, the lowest viral concentration that the assay was able to detect in stool samples was 17 CCID50/mL for nOPV1 and nOPV2 viruses and 6 CCID50/mL for nOPV3. We also found high correlation between the expected and observed (by qmosRT-PCR) concentrations of spiked viruses in stool samples for all three nOPV viruses, with R-squared values above 0.95. The analysis of samples collected from an nOPV2 clinical trial showed that 100% of poliovirus type 2 was detected and few samples showed the presence of type 1 and 3 residuals from previous vaccinations with bOPV (at least 4 weeks prior vaccination with nOPV2), confirming the high sensitivity of the method. The qmosRT-PCR was specific and sensitive for the simultaneous identification and quantification of all three nOPV viruses. It can be used as an identity test during the nOPV manufacturing process and in evaluation of virus excretion in nOPV clinical trials

    Quantitative RT-PCR Assays for Quantification of Undesirable Mutants in the Novel Type 2 Oral Poliovirus Vaccine

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    Emergence of mutations is an inherent property of RNA viruses with several implications for their replication, pathogenesis, and evolutionary adaptation. Oral poliovirus vaccine (OPV), developed by Albert Sabin, is composed of live attenuated polioviruses of three serotypes that can revert to neurovirulence during replication in cell culture and in vaccine recipients. Recently, a new modified variant of Sabin 2 virus was developed by introducing changes in its genome, making it more genetically stable to prevent the reversion. The new strain was used to manufacture novel OPV2 (nOPV2), which was approved by the World Health Organization for emergency use to stop outbreaks caused by circulating vaccine-derived poliovirus (cVDPV2). Manufacture of this improved vaccine requires close attention to the genetic heterogenicity to ensure that the levels of the undesirable mutations are limited. Preliminary studies using whole-genome Illumina sequencing (NGS) identified several genomic sites where mutations tend to occur with regularity. They include VP1-I143T amino acid change at the secondary attenuation site; VP1-N171D, a substitution that modestly increases neurovirulence in mice; and VP1-E295K, which may reduce the immunogenicity of the nOPV2. Therefore, to ensure the molecular consistency of vaccine batches, the content of these mutants must be quantified and kept within specifications. To do this, we have developed quantitative, multiplex, one-step reverse-transcriptase polymerase chain reactions (qmosRT-PCRs) as simple methods for quantification of these mutations. Each method uses specific short TaqMan probes with different dyes for the analysis of both mutants and non-mutants in the same sample. The quantification is done using calibration curves developed using validated reference materials. To evaluate the sensitivity and the linearity of the qmosRT-PCR method, the mutant viruses were spiked in non-mutant viruses, and nOPV2 batches were used to validate the method. The spiked samples and the nOPV2 batches were analyzed by qmosRT-PCR and NGS assays. The results showed that qmosRT-PCR is sensitive enough to detect around 1% of mutants. The percentages of mutants determined by qmosRT-PCR correlate well with the results of the NGS. Further, the analysis of the nOPV2 batches showed that the results of qmosRT-PCR correlated well with the results of NGS. In conclusion, the qmosRT-PCR is a specific, sensitive, and linear method. It could be used for quality control of the nOPV2 batches

    Evaluation and validation of next-generation sequencing to support lot release for a novel type 2 oral poliovirus vaccine

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    A novel, genetically-stabilized type 2 oral polio vaccine (nOPV2), developed to assist in the global polio eradication program, was recently the first-ever vaccine granted Emergency Use Listing by the WHO. Lot release tests for this vaccine included—for the first time to our knowledge—the assessment of genetic heterogeneity using next-generation sequencing (NGS). NGS ensures that the genetically-modified regions of the vaccine virus genome remain as designed and that levels of polymorphisms which may impact safety or efficacy are controlled during routine production. The variants present in nOPV2 lots were first assessed for temperature sensitivity and neurovirulence using molecular clones to inform which polymorphisms warranted formal evaluation during lot release. The novel use of NGS as a lot release test required formal validation of the method. Analysis of an nOPV2 lot spiked with the parental Sabin-2 strain enabled performance characteristics of the method to be assessed simultaneously at over 40 positions in the genome. These characteristics included repeatability and intermediate precision of polymorphism measurement, linearity of both spike-induced and nOPV2 lot-specific polymorphisms, and the limit-of-detection of spike-induced polymorphisms. The performance characteristics of the method met pre-defined criteria for 34 spike-induced polymorphic sites and 8 polymorphisms associated with the nOPV2 preparation; these sites collectively spanned most of the viral genome. Finally, the co-location of variants of interest on genomes was evaluated, with implications for the interpretation of NGS discussed

    Evaluating stability of attenuated Sabin and two novel type 2 oral poliovirus vaccines in children

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    Novel oral poliovirus vaccine type 2 (nOPV2) is being developed to reduce the rare occurrence of disease and outbreaks associated with the genetic instability of the Sabin vaccine strains. Children aged 1 to 5 years were enrolled in two related clinical studies to assess safety, immunogenicity, shedding rates and properties of the shed virus following vaccination with nOPV2 (two candidates) versus traditional Sabin OPV type 2 (mOPV2). The anticipated pattern of reversion and increased virulence was observed for shed Sabin-2 virus, as assessed using a mouse model of poliovirus neurovirulence. In contrast, there were significantly reduced odds of mouse paralysis for shed virus for both nOPV2 candidates when compared to shed Sabin-2 virus. Next-generation sequencing of shed viral genomes was consistent with and further supportive of the observed neurovirulence associated with shed Sabin-2 virus, as well as the reduced reversion to virulence of shed candidate viruses. While shed Sabin-2 showed anticipated A481G reversion in the primary attenuation site in domain V in the 5' untranslated region to be associated with increased mouse paralysis, the stabilized domain V in the candidate viruses did not show polymorphisms consistent with reversion to neurovirulence. The available data from a key target age group for outbreak response confirm the superior genetic and phenotypic stability of shed nOPV2 strains compared to shed Sabin-2 and suggest that nOPV2 should be associated with less paralytic disease and potentially a lower risk of seeding new outbreaks
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