Development of recombinant rotavirus carrying herpes simplex virus 2 glycoprotein D gene based on reverse genetics technology.

Vaccine development for herpes simplex virus 2 (HSV-2) has been attempted, but no vaccines are yet available. A plasmid-based reverse genetics system for Rotavirus (RV), which can cause gastroenteritis, allows the generation of recombinant RV containing foreign genes. In this study, we sought to develop simian RV (SA11) as a vector to express HSV-2 glycoprotein D (gD2) and evaluated its immunogenicity in mice. We generated the recombinant SA11-gD2 virus (rSA11-gD2) and confirmed its ability to express gD2 in vitro. The virus was orally inoculated into suckling BALB/c mice and into 8-week-old mice. Serum IgG and IgA titers against RV and gD2 were measured by ELISA. In the 8-week-old mice inoculated with rSA11-gD2, significant increases in not only antibodies against RV but also IgG against gD2 were demonstrated. In the suckling mice, antibodies against RV were induced, but gD2 antibody was not detected. Diarrhea observed after the first inoculation of rSA11-gD2 in suckling mice was similar to that induced by the parent virus. A gD2 expressing simian RV recombinant, which was orally inoculated, induced IgG against gD2. This strategy holds possibility for genital herpes vaccine development.

Herpes Simplex Virus 2 in Autonomic Ganglia: Evidence for Spontaneous Reactivation.

Herpes simplex virus 2 (HSV-2) can be transmitted in the presence or absence of lesions, allowing efficient spread among the general population. Recurrent HSV genital lesions are thought to arise from reactivated latent virus in sensory cell bodies of the dorsal root ganglia (DRG). However, HSV-2 has also been found latent in autonomic ganglia. Spontaneous reactivation or a low level of chronic infection could theoretically also occur in these peripheral nervous tissues, contributing to the presence of infectious virus in the periphery and to viral transmission. Use of a recently described, optimized virus with a monomeric mNeonGreen protein fused to viral capsid protein 26 (VP26) permitted detection of reactivating virus in explanted ganglia and cryosections of DRG and the sacral sympathetic ganglia (SSG) from latently infected guinea pigs. Immediate early, early, and late gene expression were quantified by droplet digital reverse transcription-PCR (ddRT-PCR), providing further evidence of viral reactivation not only in the expected DRG but also in the sympathetic SSG. These findings indicate that viral reactivation from autonomic ganglia is a feature of latent viral infection and that these reactivations likely contribute to viral pathogenesis.IMPORTANCE HSV-2 is a ubiquitous important human pathogen that causes recurrent infections for the life of its host. We hypothesized that the autonomic ganglia have important roles in viral reactivation, and this study sought to determine whether this is correct in the clinically relevant guinea pig vaginal infection model. Our findings indicate that sympathetic ganglia are sources of reactivating virus, helping explain how the virus causes lifelong recurrent disease.

A VP26-mNeonGreen Capsid Fusion HSV-2 Mutant Reactivates from Viral Latency in the Guinea Pig Genital Model with Normal Kinetics.

Fluorescent herpes simplex viruses (HSV) are invaluable tools for localizing virus in cells, permitting visualization of capsid trafficking and enhancing neuroanatomical research. Fluorescent viruses can also be used to study virus kinetics and reactivation in vivo. Such studies would be facilitated by fluorescent herpes simplex virus recombinants that exhibit wild-type kinetics of replication and reactivation and that are genetically stable. We engineered an HSV-2 strain expressing the fluorescent mNeonGreen protein as a fusion with the VP26 capsid protein. This virus has normal replication and in vivo recurrence phenotypes, providing an essential improved tool for further study of HSV-2 infection.