Baculovirus capsid display: a novel tool for transduction imaging

Area of Science:

• * Virology
• * Molecular Biology
• * Gene Therapy

Background:

• * Baculoviruses are enveloped insect viruses with large foreign DNA capacity.
• * They show promise as gene therapy vectors, but mammalian transduction mechanisms are poorly understood.
• * Autographa californica multiple nuclear polyhedrosis virus (AcMNPV) is a key baculovirus of interest.

Purpose of the Study:

• * To investigate baculovirus transduction mechanisms in mammalian cells.
• * To explore the utility of modified baculovirus capsids for protein display and gene delivery.
• * To identify the specific barriers to baculovirus entry and transport in mammalian systems.

Main Methods:

• * Genetic modification of the AcMNPV major capsid protein (vp39) for N- or C-terminal fusions.
• * Generation of enhanced green fluorescent protein (EGFP)-displaying baculoviruses.
• * Confocal and electron microscopy to track viral entry and intracellular transport in mammalian cells.
• * In vivo biodistribution studies using EGFP-tagged baculoviruses.

Main Results:

• * Baculovirus capsid modification (vp39 fusions) is compatible with viral titer and functionality.
• * EGFP-displaying baculoviruses allow visualization of transduction in mammalian cells.
• * Transduction blockage occurs in cytoplasmic transport or nuclear entry, not endosomal escape.
• * EGFP-tagged baculoviruses enable in vivo biodistribution tracking.

Conclusions:

• * Baculovirus capsid engineering is feasible for protein display and gene delivery applications.
• * Mammalian cell entry barriers for baculoviruses are identified as post-endosomal.
• * Modified baculoviruses offer potential for targeted gene delivery and as a peptide display system.