Abstract:
Lentiviral vectors are biological vehicles used to deliver therapeutic genes (“payload”) into cells. The characterization of lentiviral vectors is challenging due to their complex physical structure. To be considered functional, lentiviral vectors require at least three critical components:
(1) An outer envelope, comprised of VSV-G protein (2) A capsid housing the genetic material, comprised of p24 protein and (3) The payload itself constituted by the therapeutic gene.
Since there is no assay currently on the market that measures all three attributes, scientists must piece together data from several different assays to understand the composition of the vector, which is often laborious and unreliable. Currently, a microarray chip-based assay on the market can offer a partial characterization of lentiviruses. However, this assay does not provide any information on the presence or absence of the payload. This is an integral piece of information which would determine the functionality of the lentiviral vector.
In this study, we developed a new characterization method that selectively targets VSV-G, p24 and the RNA payload by using a permeant fluorescent nucleic acid stain a. Using this method, we can quickly visualize and quantitate the lentiviral vector at three separate levels for a comprehensive understanding of lentiviral vector products. Importantly, this method can enable new vector design and process optimization to enrich full lentiviral vectors.
Author: Vijetha Bhat, MS, Scientist II, R&D