Project description:A human embryonic fibroblast cell line was synchronously infected with poliovirus in the absence or presence of interferon-α, or with vacciniavirus, a virus that is not inhibited by interferon. The titers were sufficient to yield productive infection in a majority of the cells. The cells were harvested in triplicate at various time-points, and the transcriptosome compared with mock infected cells using oligo-based 35 k microarrays. The project had two purposes: to characterize the cellular response and to look for candidate genes involved in viral defense. The changes in gene expression due to vaccinia virus did not correspond to those caused by poliovirus. More surprisingly, neither did the changes when comparing 8 h and 16 h of poliovirus infection. However, a large proportion of the genes up-regulated by interferon-α were also up-regulated by poliovirus, both at 8 h and 16 h. Interferon-α inhibited poliovirus replication, thus the observations suggest that the cells do launch an antiviral response to poliovirus. Moreover, as interferon genes were not induced, the data indicate that several of the relevant genes can be activated in an interferon independent manner. Further analyses of the data led to a list of candidate antiviral genes. Functional information was limited, or absent, for most of these genes. Keywords: Poliovirus; Vacciniavirus; Interferon; Microarray; Gene expression; Defense genes
Project description:The COVID-19 pandemic has generated intense interest in the rapid development and evaluation of vaccine candidates for this disease and other emerging diseases. Several novel methods for preparing vaccine candidates are currently undergoing clinical evaluation in response to the urgent need to prevent the spread of COVID-19. In many cases, these methods rely on new approaches for vaccine production and immune stimulation. We report on the use of a novel method (SolaVAXTM) for production of an inactivated vaccine candidate and the testing of that candidate in a hamster animal model for its ability to prevent infection upon challenge with SARS-CoV-2 virus. The studies employed in this work included an evaluation of the levels of neutralizing antibody produced post-vaccination, levels of specific antibody sub-types to RBD and spike protein that were generated, evaluation of viral shedding post-challenge, flow cytometric and single cell sequencing data on cellular fractions and histopathological evaluation of tissues post-challenge. The results from this study provide insight into the immunological responses occurring as a result of vaccination with the proposed vaccine candidate and the impact that adjuvant formulations, specifically developed to promote Th1 type immune responses, have on vaccine efficacy and protection against infection following challenge with live SARS-CoV-2. This data may have utility in the development of effective vaccine candidates broadly. Furthermore, the results suggest that preparation of a whole virion vaccine for COVID-19 using this specific photochemical method may have utility in the preparation of one such vaccine candidate.
2021-02-19 | GSE165190 | GEO
Project description:Identification of novel genetic variants in the malaria vaccine candidate PfRh5 in Senegal
Project description:Zika virus (ZIKV) is a mosquito-transmitted positive-sense RNA virus in the family Flaviviridae. Candidate live-attenuated vaccine (LAV) viruses with engineered deletions in the 3’UTR provide immunity and protection in animal models of ZIKV infection, and phenotypic studies show that LAVs retain protective abilities following in vitro passage. The present study investigates the genetic diversity of wild-type (WT) parent ZIKV and its candidate LAVs using next generation sequencing analysis of five sequential in vitro passages. ZIKV RNA from was transfected into Vero cells, incubated for nine days, harvested, and clarified by centrifugation to generate passage 0 (P0) ZIKV infectious clones. Subsequently, P0 ZIKVs were blind-passaged into fresh cultures to generate P1, then serially through P5. P1-P5 stocks were harvested from cell media at 4-5 days post-infection. ZIKV RNA from 3’UTR deletion mutants were transfected into Vero cells, incubated for nine days, harvested, and clarified by centrifugation to generate passage 0 (P0) ZIKV infectious clones. Subsequently, P0 ZIKVs were blind-passaged into fresh cultures to generate P1, then serially through P5. P1-P5 stocks were harvested from cell media at 4-5 days post-infection. Genetic diversity of the viruses were assessed by evaluating both the variability (or uncertainty) at each nucleotide position was determined using Shannon entropy calculations and identified single nucleotide variants (SNVs). The results showed both the parental WT and LAV derivatives increase in genetic diversity with evidence of adaptation following passage.
Project description:Comparative proteomics was conducted for Synechocystis sp. PCC 6803 wild type and engineered ethylene-producing JU547 strains. An novel guanidine-degradation enzyme was identified and characterized to play important roles in genome stability.
Project description:With the advent of advanced sequencing technology, studies of RNA viruses have shown that genetic diversity contribute to both attenuation and virulence. The differences in genetic diversity of wild-type Asibi virus and 17D-204 vaccine provides an unique opportunity to investigate RNA population theory in the context of a well described live attenuated vaccine. Utilizing infectious clone-derived viruses containing some of the amino acid substitutions that differentiate yellow fever wild-type Asibi strain from 17D vaccine and recovered in a controlled experiment, establishes that the genetic diversity differences that exist between wild-type Asibi and 17D-204 vaccine viruses are not influenced by either different passage history or source of samples, but rather resulted from the attenuation of wild-type Asibi virus to yield the 17D vaccine sub-strains.