Impact of E1 and Cre on adenovirus vector amplification: developing MDCK CAV-2-E1 and E1-Cre transcomplementing cell...

Area of Science:

• Molecular Biology
• Virology
• Biotechnology

Background:

• Adenovirus vectors are crucial tools in gene therapy and research.
• Producer cell line optimization often overlooks the expression of transcomplementing genes.
• Understanding the role of these genes is key to improving vector production.

Purpose of the Study:

• To investigate the impact of E1 (E1A, E1B) and Cre recombinase expression levels on canine adenovirus type 2 (CAV-2) vector production.
• To correlate gene expression profiles with cell productivity and resistance to oxidative stress.
• To identify optimal conditions for establishing high-performance CAV-2 producer cell lines.

Main Methods:

• Utilized MDCK cells for producing E1-deleted and helper-dependent CAV-2 vectors.
• Quantified E1A, E1B gene expression, and Cre recombinase activity in different cell clones.
• Assessed cell productivity (I.P./cell) and susceptibility to oxidative stress post-infection.
• Evaluated the interplay between E1B's anti-apoptotic effects and Cre recombinase activity.

Main Results:

• CAV-2 production directly correlated with E1A expression levels, reaching 3000-5000 I.P./cell.
• E1B expression enhanced host cell survival by protecting against apoptosis post-infection.
• Cre recombinase partially counteracted E1B's anti-apoptotic effects, but high Cre levels maintained viral production.
• Reduced Cre activity in cell lines maintained excision efficiency without compromising viral yield.

Conclusions:

• Transcomplementing gene expression significantly influences CAV-2 producer cell line performance.
• High expression of E1A and E1B is critical for efficient CAV-2 vector production and cell line establishment.
• Fine-tuning Cre recombinase levels offers a strategy to balance viral production and minimize side effects.