Infectious titer determination of lentiviral vectors using a temporal immunological real-time imaging approach

PLoS One. 2021 Jul 15;16(7):e0254739. doi: 10.1371/journal.pone.0254739. eCollection 2021.

Abstract

The analysis of the infectious titer of the lentiviral vector samples obtained during upstream and downstream processing is of major importance, however, also the most challenging method to be performed. Currently established methods like flow cytometry or qPCR lack the capability of enabling high throughput sample processing while they require a lot of manual handling. To address this limitation, we developed an immunological real-time imaging method to quantify the infectious titer of anti-CD19 CAR lentiviral vectors with a temporal readout using the Incucyte® S3 live-cell analysis system. The infective titers determined with the Incucyte® approach when compared with the flow cytometry-based assay had a lower standard deviation between replicates and a broader linear range. A major advantage of the method is the ability to obtain titer results in real-time, enabling an optimal readout time. The presented protocol significantly decreased labor and increased throughput. The ability of the assay to process high numbers of lentiviral samples in a high throughput manner was proven by performing a virus stability study, demonstrating the effects of temperature, salt, and shear stress on LV infectivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Flow Cytometry
  • Genetic Vectors
  • HEK293 Cells
  • Humans
  • Lentivirus*
  • Transduction, Genetic*
  • Transfection

Grants and funding

This research was funded by Sartorius Stedim Biotech GmbH. Essen BioScience Ltd. is part of the Sartorius group. The funder as a legal entity provided support in the form of salaries for all authors but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript which activities were the authors’ sole responsibilities in their respective functions as Sartorius’ employees or working student. The specific roles of these authors are articulated in the ‘author contributions’ section.