Abstract
The neuroinvasive Herpes simplex virus type 1 (HSV-1) utilizes intergenomic recombination in order to diversify viral populations. Research efforts to assess HSV-1 recombination are often complicated by the use of attenuating mutations, which differentiate viral progeny but unduly influence the replication and spread. In this work, we generated viruses with markers that allowed for classification of viral progeny with limited attenuation of viral replication. We isolated viruses, harboring either a cyan (C) or yellow (Y) fluorescent protein (FP) expression cassette inserted in two different locations within the viral genome, in order to visually quantify the recombinant progeny based on plaque fluorescence. We found that the FP marked genomes had a limited negative affect on the viral replication and production of progeny virions. A co-infection of the two viruses resulted in recombinant progeny that was dependent on the multiplicity of infection and independent of the time post infection, at a rate that was similar to previous reports. The sequential passage of mixed viral populations revealed a limited change in the distribution of the parental and recombinant progeny. Interestingly, the neuroinvasive spread within neuronal cultures and an in vivo mouse model, revealed large, random shifts in the parental and recombinant distributions in viral populations. In conclusion, our approach highlights the utility of FP expressing viruses in order to provide new insights into mechanisms of HSV-1 recombination.
Highlights
Herpes Simplex virus type 1 (HSV-1) is a persistent and pervasive human pathogen with global relevance [1,2]
The viruses that were developed for the recombination expressing yellow fluorescent protein (YFP) with a nuclear localization sequence (NLS) (HSV-1 OK12, first described in [21] and referred to here in the manuscript as HSV-1 YFPUL ) and cyan fluorescent protein (CFP)-NLS (HSV-1 MT002 referred to as HSV-1 CFPUS in the manuscript), which were both derived from the HSV-1 strain 17
The first virus contained an insert between the viral genes UL 37/38 that drove the expression of a nuclear localized YFP
Summary
Herpes Simplex virus type 1 (HSV-1) is a persistent and pervasive human pathogen with global relevance [1,2]. Infections of HSV-1 typically manifest in the mucosal or epithelial surfaces. All HSV-1 infections will spread into peripheral neurons. The peripheral neurons remain persistently infected with HSV-1 for the lifespan of the host, spreading the virus either back to sites of primary infection or into neurons of the central nervous system, where it can cause severe encephalitis [3,4]. Recombination is a primary driver of the genomic diversity and evolution of HSV-1. In order for recombination to occur, cells within the host tissues must become infected by multiple virions. The viral genomes are able to exchange DNA during replication, in order to generate the recombinant genomes, which are packaged into progeny virions.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
