New Cytometry Technique for Characterizing Viral Vectors

Kite Pharma, a subsidiary of Gilead, has introduced a novel method for examining individual lentiviral vector particles. This technique aims to provide a more comprehensive understanding of the vectors than conventional Western blotting. Kristen Kellar, an analytical development scientist at Kite, emphasized the importance of thoroughly understanding these particles, given the still-emerging nature of in vivo lentiviral vector delivery.

Priti Hegde, senior vice president of research and development, added that the new method holds potential for various gene and cell therapies utilizing enveloped viruses.

The innovative technique utilizes flow virometry, enabling individual particles to pass through a detector where their size and surface proteins can be analyzed. This approach preserves the unique characteristics of each particle, avoiding the loss of detailed information often seen in averaging methods. For instance, if one particle has significantly more of a specific protein than another, the new method can capture this distinction, unlike Western blotting which would average the results and present an inaccurate representation.

While flow virometry has been employed in the past, recent advancements in instruments designed for nanoparticle analysis have significantly enhanced its capabilities. These improvements allow for the detection of a broader range of particles and ensure they are of the correct size. A novel feature of the new method is the ability to stain proteins on the particle surface, revealing an abundant protein of interest that was previously undetectable.

Kite Pharma intends to implement this technology throughout their product development process, including during the final stages to evaluate batch consistency. They are also exploring the use of quantitation bead sets, which will enable the precise quantification of viral proteins on the vector surface. Hegde noted that the field of in vivo cell therapy is still in its infancy, so the team is excited to witness clinical proof of concept and is focused on scaling the technology robustly.