Tailoring the Methods of Conjugation and Characterization for a Replication-Competent, Live, Viral Vector

Optimized functionalization of virus particles can expand
the toolbox
available for the development of viral vector-based therapies. However,
labeling of a large, complex, and biologically active particle introduces
distinct technological challenges for subsequent purification and
characterization steps. Moreover, the process of labeling and purification,
and even the label itself, may have an unwanted impact on the particle’s
biological activity. Herein, we present a comprehensive series of
steps for conjugation, purification, and characterization that are
adapted from traditional biologics (e.g., monoclonal antibodies) and
apply them to the replication-competent rhabdovirus VSV-GP-GFP. By
confirming purity and quantifying the average degree of labeling (DoL),
we tailored the label/particle ratio to generate tool viruses suitable
for downstream applications in nonclinical and clinical development.
These methods will enhance the development of viral vector therapies
and hasten their delivery to patients in need.