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.