Biology subjects

Destro, F.

Publications and source records attributed to Destro, F..

2 recordsLinked to original sources

bioRxiv2024

Efficient Simulation of Viral Transduction and Propagation for Biomanufacturing

Viral transduction is a main route for gene transfer to producer cells in biomanufacturing. Designing a transduction-based biomanufacturing process poses significant challenges, due to the complex dynamics of viral infection and virus-host interaction. This article introduces a software toolkit composed of a multiscale model and an efficient numeric technique that can be leveraged for determining genetic and process designs that optimize transduction-based biomanufacturing platforms. Viral transduction and propagation for up to two viruses simultaneously can be simulated through the model, considering viruses in either lytic or lysogenic stage, during batch, perfusion, or continuous operation. The model estimates the distribution of the viral genome(s) copy number in the cell population, which is an indicator of transduction efficiency and viral genome stability. The infection age distribution of the infected cells is also calculated, indicating how many cells are in an infection stage compatible with recombinant product expression and/or with viral amplification. The model can also consider the presence in the system of defective interfering particles, which can severely compromise the productivity of biomanufacturing processes. Model benchmarking and validation are demonstrated for case studies on the baculovirus expression vector system and influenza A propagation in suspension cultures. TOC Graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/587435v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@1752f59org.highwire.dtl.DTLVardef@779987org.highwire.dtl.DTLVardef@8d14org.highwire.dtl.DTLVardef@2e4514_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

bioRxiv2023

Mechanistic Modeling Explains the Production Dynamics of Recombinant Adeno-Associated Virus with the Baculovirus Expression Vector System

The demand for recombinant adeno-associated virus (rAAV) for gene therapy is expected to soon exceed current manufacturing capabilities, considering the expanding number of approved products and of pre-clinical and clinical stage studies. Current rAAV manufacturing processes have less-than-desired yields and produce a significant amount of empty capsids. Recently, FDA approved the first rAAV-based gene therapy product manufactured in the baculovirus expression vector system (BEVS). The BEVS technology, based on an invertebrate cell line derived from Spodoptera frugiperda, demonstrated scalable production of high volumetric titers of full capsids. In this work, we develop a mechanistic model describing the key extracellular and intracellular phenomena occurring during baculovirus infection and rAAV virion maturation in the BEVS. The predictions of the model show good agreement with experimental measurements reported in the literature on rAAV manufacturing in the BEVS, including for TwoBac, ThreeBac, and OneBac constructs. The model is successfully validated against measured concentrations of structural and non-structural protein components, and of vector genome. We carry out a model-based analysis of the process, to provide insights on potential bottlenecks that limit the formation of full capsids. The analysis suggests that vector genome amplification is the limiting step for rAAV production in TwoBac. In turn, vector genome amplification is limited by low Rep78 levels. For ThreeBac, low vector genome amplification dictated by Rep78 limitation appears even more severe than in TwoBac. Transgene expression in the insect cell during rAAV manufacturing is also found to negatively influence the final rAAV production yields.

molecular biology↗