Genetic and Molecular Analysis of Herpes Simplex Virus Assembly in vivo in Mouse Visual System Neurons

Abstract

Abstract: : Purpose: Herpes simplex virus infects both epithelial cells and neuronal cells of the human host. Although HSV assembly has been studied extensively in cultured epithelial and neuronal cells, cultured neurons, as well as other epithelial cells, behave biochemically, physiologically and anatomically significantly different than mature neurons in situ. Therefore, it is imperative that viral maturation and assembly be studied in vivo. Methods: To study viral assembly in vivo, we have inoculated wild–type and replication–defective viruses into the posterior chamber of the eyes of mice and followed the events of infection in retinal ganglion cells and their axons using PCR techniques to detect viral DNA and RNA and EM immunocytochemistry and western blotting to detect viral proteins in specific portions of the optic tract. Results: This approach has shown that viral DNA replication is necessary for viral DNA movement into axons. Viral DNA movement in the axon occurs within capsids and is independent of viral envelope protein movement in the axon. Conclusions: These studies show the power of an approach involving intravitreal injection of replication–defective viruses for the analysis of essential components of HSV during infection of retinal ganglion cells in the intact murine visual system, an approach that should allow further genetic analysis of essential viral replication and maturation processes in neurons in vivo.

Keywords: herpes simplex virus • retinal degenerations: cell biology • ganglion cells