Max Planck Institute for Dynamics of Complex Technical Systems
Understanding viral replication is not only crucial for the development of new antiviral drugs but can also lead to novel biotechnological strategies for the optimization of vaccine and viral vector production. Thus, the research team “Molecular Biology” (MolBio) of the Bioprocess Engineering department is analyzing the intracellular viral life cycle steps and virus-host cell interactions on the molecular level. It is our aim to identify bottlenecks of virus replication, or determinants of efficient virus spread and pathogenesis. Furthermore, we are aiming for the development of strategies to increase cell-specific virus yields in animal cell culture. For instance, we investigate the impact of so-called defective interfering particles (DIPs) on the quality of seed virus and virus production yields, and explore options to use DIPs and their antiviral responses for new therapeutic and preventive approaches.
For the analysis of the complex interplay between influenza viruses and their host cells, sophisticated analytical methods such as real-time RT-qPCR and imaging flow cytometry in combination with mathematical modeling are essential. Moreover, single-cell analysis is an important novel tool to study details regarding the design of highly efficient vaccine production processes. In particular, we observed that the majority of individually infected cells is non-productive or releases relatively few progeny virions. However, some cells produce very high virus titers. We were able to demonstrate that this high cell-to-cell heterogeneity in influenza A virus infection is caused by stochastic fluctuations that are intrinsic to viral replication and by extrinsic noise, which can originate from cellular factors. In conclusion, the detailed investigation of virus replication in production cell lines using state-of-the-art analytical tools and mathematical modeling paves the way to optimize virus production by the targeted design of cell lines and virus strains and supports development of new antiviral strategies.
Pelz, L.; Rüdiger, D.; Alnaji, F. G.; Genzel, Y.; Brooke, C. B.; Kupke, S. Y.; Reichl, U.: Semi-continuous propagation of influenza A virus and its defective interfering particles: analyzing the dynamic competition to select candidates for antiviral therapy. bioRxiv (2021)
Kupke, S. Y.; Riedel, D.; Frensing, T.; Zmora, P.; Reichl, U.: A Novel Type of Influenza A Virus-Derived Defective Interfering Particle with Nucleotide Substitutions in Its Genome. Journal of Virology 93 (4), 01786-18 (2019)
Wasik, M.; Eichwald, L.; Genzel, Y.; Reichl, U.: Cell culture-based production of defective interfering particles for influenza antiviral therapy. Applied Microbiology and Biotechnology 102 (3), pp. 1167 - 1177 (2018)
Laske, T.; Heldt, F. S.; Hoffmann, H.; Frensing, T.; Reichl, U.: Modeling the intracellular replication of influenza A virus in the presence of defective interfering RNAs. Virus Research 213, pp. 90 - 99 (2016)
Heldt, F. S.; Frensing, T.; Reichl, U.: Modeling the intracellular dynamics of influenza virus replication to understand the control of viral RNA synthesis. Journal of Virology 86 (15), pp. 7806 - 7817 (2012)
Seitz, C.; Isken, B.; Heynisch, B.; Rettkowski, M.; Frensing, T.; Reichl, U.: Trypsin promotes efficient influenza vaccine production in MDCK cells by interfering with the antiviral host response. Applied Microbiology and Biotechnology 93 (2), pp. 601 - 611 (2012)
Seitz, C.; Frensing, T.; Höper, D.; Kochs, G.; Reichl, U.: High yields of Influenza A virus in MDCK cells are promoted by an insufficient IFN-induced antiviral state. Journal of General Virology 91 (7), pp. 1754 - 1763 (2010)