Project description:On-demand biomanufacturing has the potential to improve healthcare and self- sufficiency during space missions. Cell-free transcription and translation reactions combined with DNA blueprints can produce promising therapeutics like bacteriophages and virus-like particles. However, how space conditions affect the synthesis and self-assembly of such complex multi- protein structures is unknown. Here, we characterize the cell-free production of infectious bacteriophage T7 virions under simulated microgravity. Rotation in a 2D-clinostat increased the number of infectious particles compared to static controls. Quantitative analyses by mass spectrometry, immuno-dot-blot and real-time PCR showed no significant differences in protein and DNA contents, suggesting enhanced self-assembly of T7 phages in simulated microgravity. While the effects of genuine space conditions on the cell-free synthesis and assembly of bacteriophages remain to be investigated, our findings support the vision of a cell-free synthesis-enabled “astropharmacy”.
Project description:The multibasic furin cleavage site at the S1/S2 boundary of the spike protein (S protein) is a hallmark of SARS-CoV-2 and plays an crucial role in viral infection. O-glycosylation near the furin site catalyzed by host cell glycosyltransferases can theoretically hinder spike protein processing and impede viral infection, but so far such a hypothesis has not been tested with authentic viruses. The mechanism underlying furin activation also remains poorly understood. In this study, we have discovered that GalNAc-T3 and T7 jointly initiate clustered O-glycosylations in the multibasic S1/S2 boundary region. These O-glycosylations inhibit furin processing of the spike protein and surprisingly suppress the incorporation of S protein into virus-like-particles (VLPs). Mechanistic analysis revealed that the assembly of spike protein into VLPs relies on protein-protein interaction between the furin-cleaved S protein and a double aspartic motif on the membrane protein of SARS-CoV-2, suggesting a novel mechanism for furin activation of the S protein. Interestingly, a point mutation at P681, found in the alpha and delta variants of SARS-CoV-2, confers resistance to glycosylation by GalNAc-T3 and T7, thereby diminishing the inhibitory effect against furin processing. However, an additional mutation at N679 in the most recent omicron variant reverses this resistance, rendering it susceptible to glycosylation in vitro and sensitive to the expression of GalNAc-T3 and T7 in human lung cells. Together, our findings suggest a glycosylation-based defense mechanism employed by host cells against SARS-CoV-2 and unveil the intricate interplay between the host and pathogen at this critical “battlefield” as the virus initially evades and currently succumbs to host cell glycosylation..
Project description:Bacteriophages are potent therapeutics against biohazardous bacteria that are rapidly acquiring multidrug resistance. However, routine administration of bacteriophage therapy is currently impeded by a lack of safe phage production methodologies and insufficient phage characterization. We thus developed a versatile cell-free platform for host-independent production of phages targeting gram-positive and gram-negative bacteria. A few microliters of a one-pot reaction produces effective doses of phages against potentially antibiotic-resistant bacteria such as enterohemorrhagic E. coli (EAEC) and Yersinia pestis, which also possibly pose threats as biological warfare agents. We also introduce a method for transient, non-genomic phage engineering to safely confer additional functions, such as a purification tag or bioluminescence for host detection, for only one replication cycle. Using high-resolution and time-resolved mass spectrometry, we validated the expression of 40 hypothetical proteins from two different phages (T7 and CLB-P3) and identified genes in the genome of phage T7 that express exceptionally late during phage replication. Our comprehensive methodology thus allows for accelerated reverse and forward phage engineering as well as for safe and customized production of clinical-grade therapeutic bacteriophages.
2022-07-20 | PXD019543 | Pride
Project description:Directed evolution of microbial co-cultures for improved production of costly metabolites
Project description:Contagious ecthyma (Orf) is a contagious disease with worldwide distribution, caused by the epitheliotropic Orf virus (ORFV), a member of the genus Parapoxvirus. In the current study, we collected the oral mucosa tissues samples (T0, T3, T7 and T15) from sheep at 0, 3, 7 and 15 days post ORFV infection, respectively. To explore the changes of comprehensive transcriptome of host cells from oral mucosa tissues post ORFV infection, the RNA-seq transcriptome comparisons were performed on these samples. It showed that 1928, 3219 and 2646 differentially expressed genes (DEGs) were identified among T3 vs. T0, T7 vs. T0, T15 vs. T0 respectively. Through Gene Ontology (GO) analyses of the DEGs from these comparisons, it revealed that ORFV provoked the vigorous immune response of the host cells during the early stage of infection. Moreover, GO and network analysis revealed that positive and negative regulative mechanisms of apoptosis worked as whole in the host cells, in order to reach a homeostasis of oral mucosa tissues.
Project description:Background: Thyroxine (T4) is generally considered to be a pro-hormone that requires conversion to 3,5,3’-triiodothyronine (T3) to exert biological activity. Although evidence suggests that T4 has intrinsic activity, it is questionable if this activity has any physiological relevance. Methods: To answer this question, triple KO mice (Triples) that cannot express the types 1 (D1) and 2 (D2) deiodinase and the Pax8 genes were generated. Thus they lack a thyroid and cannot convert T4 to T3. Triples were injected on alternate days with either vehicle or physiological doses of T4, T3 or T3+T4 from postnatal days 2 to 14. They were euthanized at P15 and RNA-seq was employed to profile gene expression in liver. In another experiment, Pax8KO mice were injected with T3, T4 or T4 +T3, and growth rate and survival to P84 were determined. Results: The growth retardation of Triples was not improved by either T3 or T4 alone but was significantly improved by T4+T3. In liver, T4 significantly regulated the expression of genes that were also regulated by T3, but the proportion of genes that were negatively regulated was higher in mice treated with T4 than with T3. Treatment with T4+T3 identified genes that were regulated synergistically by T3 and T4, and genes that were regulated only by T4+T3. Analysis of these genes revealed enrichment in mechanisms related to cell proliferation and cholesterol physiology, suggesting a unique contribution of T4 to these biological functions. Pax8KO mice all survived to P84 when injected with T4 or T4+T3 but survival rate with T3 was 50% and 10% at 3.5 and 12 weeks of life, respectively. Conclusion: T4 has intrinsic activity in vivo and is critical for survival and growth. At a physiological level, T4 per se can up- or down-regulate many T3 target genes in the neonatal liver. While most of these genes are also regulated by T3, subsets respond exclusively to T4 or demonstrate enhanced or normalized expression only in the presence of both hormones. These studies demonstrate for the first time a complex dependency on both T4 and T3 for normal mammalian growth and development.
2021-03-31 | GSE154156 | GEO
Project description:Evolution of UV resistance in T7