Influenza viruses require an acidic endosomal environment to uncoat and replicate efficiently. Standard Vero cells struggle with sufficient acidification, creating a yield bottleneck in cell-culture-based vaccine manufacturing.

In a new publication in Vaccine, our collaborators at Capricorn Technologies, alongside Evercyte, LT Biotech, and the Slovak Medical University, present AEX-1: a novel Vero cell variant engineered to overcome this exact bottleneck.

💡 Key Findings:

  • Enhanced Endosomal Acidification: AEX-1 features a measurably more acidic endosomal-lysosomal compartment, a phenotype that remains stable across 50+ population doublings.
  • Dramatic Yield Improvements: At the 72-hour harvest point, AEX-1 achieved H1N1 and Influenza B vaccine virus titers 0.9–1.7 log₁₀ higher than parental Vero cells—approaching traditional egg yields.
  • Higher Yields for Clinical Isolates: For a contemporary H3N2 isolate lacking egg-adaptive HA mutations, AEX-1 delivered up to a 3.0 log₁₀ increase in viral yield compared to standard Vero.

🧬 TAmiRNA’s Contribution: Our team performed whole-transcriptome RNA sequencing to connect this phenotype directly to its underlying biology. Among the differentially expressed genes, a coherent set points to endosomal pH regulation, matching the functional imaging. Key drivers include the upregulation of ATP6V1C2 (a vacuolar ATPase subunit) alongside solute carriers for proton and ion transport.

Congratulations to lead authors Artem Krokhin, Julia Romanova, Andrej Egorov, and all collaborating co-authors on this outstanding milestone in vaccine bioprocessing! 👏