Logo image
Back
LOW TEMPERATURE ENTRY OF HERPES SIMPLEX VIRUS 1 AND FUNCTIONS OF THE CYTOPLASMIC TAIL OF OVINE HERPESVIRUS 2 GLYCOPROTEIN B
Dissertation

LOW TEMPERATURE ENTRY OF HERPES SIMPLEX VIRUS 1 AND FUNCTIONS OF THE CYTOPLASMIC TAIL OF OVINE HERPESVIRUS 2 GLYCOPROTEIN B

Colleen Mary Lynch
Doctor of Philosophy (PhD), Washington State University
2026
pdf
LYNCH Low temperature entry of herpes simplex virus 1 and functions of the cytoplasmic tail of ovine herpesvirus 2 glycoprotein b (3)
Embargoed Access, Embargo ends: 07/17/2028

Abstract

Herpes simplex virus 1 Herpesvirales Ovine herpesvirus 2 Viral entry Viral glycoproteins
Herpesviruses are important pathogens of both humans and animals. Entry into the host cell is a complex process involving multiple host and viral factors which remain incompletely understood but are of interest as potential targets for the development of vaccines and treatments. Fusion in particular is an essential step, requiring at minimum three conserved glycoproteins (B, H, and L) in addition to species specific envelope glycoproteins and host cell receptors. Here we investigated the fusion mechanisms of two important herpesviruses. Ovine herpesvirus 2 (OvHV-2) causes the fatal veterinary disease malignant catarrhal fever (MCF) but cannot be propagated in vitro, so a robust virus-free cell-cell membrane fusion assay is necessary to elucidate its entry mechanism. We hypothesize that enhancing the cell surface expression of gB, the core herpesviral fusogen, will increase cell-cell fusion to provide a more robust assay and aid in further research. We generated C-terminal truncation mutants of gB and determined their cell surface expression, subcellular distribution, and fusion activity. This study demonstrated that the OvHV-2 gB cytoplasmic tail is critical for fusion and that a gB mutant truncated at amino acid 847 showed increased surface expression and fusion relative to wild type. This mutant gB847 may be used in place of wild type gB in an improved, more robust OvHV-2 fusion assay. Herpes simplex virus 1 (HSV-1) is an important and ubiquitous pathogen of humans worldwide for which there is currently no vaccine and limited options for treatment. Strains with atypical entry phenotypes are useful tools for investigating specific entry mechanisms. HSV-1 strain ANG path exhibits many such entry phenotypes. We investigated the determinants of fusion and entry by this strain at low temperatures. We demonstrated that in cell types where the virus enters by direct plasma membrane fusion, glycoprotein D and the cellular entry receptor are key determinants, whereas in human keratinocytes where the virus typically enters via the pH-dependent endocytic pathway gB appears to play a more significant role. These findings raise the possibility of an additional entry receptor in keratinocytes, potentially interacting with gB during low temperature entry, and prompts further investigation of these mechanisms in this pathophysiologically relevant cell line.

Metrics

1 Record Views

Details

Logo image