Dissertation
ACID-INDUCED CHANGES IN HERPES SIMPLEX VIRUS GLYCOPROTEIN B AND THEIR REVERSIBILITY
Doctor of Philosophy (PhD), Washington State University
01/2018
Handle:
https://hdl.handle.net/2376/117350
Abstract
Herpes simplex virus (HSV) is an enveloped virus. It must fuse with a host cell membrane to initiate entry and infection. HSV requires at least four proteins for fusion, glycoprotein D (gD), gH/gL, and the core fusogen, gB. gB is a member of the class III fusion protein family, which undergo hallmark reversible conformational changes following exposure to acidic pH. Entry of HSV can occur via multiple routes, including low pH dependent entry into epithelial cells, which is the primary site of infection. Exposure of virions to acidic pH for 10 min results in a conformational change in gB that is reversible following neutralization back to neutral pH, consistent with other class III fusion proteins. Treatment of virions with low pH in the absence of a target membrane reduces infectivity, a trait consistent with viruses that utilize low pH entry to fuse with host cell membranes. Here, we show that fusion is the likely step inhibited by acid pretreatment of HSV-1. We utilized monoclonal antibodies to further characterize the gB oligomer and found they differentially react during low pH oligomeric change. We developed a transfected cell oligomeric change assay that will allow us to probe specific residues required for gB conformational change and reversibility. Treating HSV for either prolonged periods of time (3 hr) with acidic pH, or alternating between acid pH and neutralization sequential treatments resulted in >2 log loss of infectivity that correlated with an irreversible change in the H126 epitope of gB. Surprisingly in both cases gB oligomeric change remained reversible. Treatment of HSV with elevated temperature alone did not result in an irreversible change in gB, but when combined with acidic pH, the H126 change was irreversible, while oligomeric change remained reversible. These results suggest the target of low-pH inactivation is the step of fusion, likely gB, and that the antigenic change in the H126 epitope is distinct from the oligomeric change.
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Details
- Title
- ACID-INDUCED CHANGES IN HERPES SIMPLEX VIRUS GLYCOPROTEIN B AND THEIR REVERSIBILITY
- Creators
- Darin Weed
- Contributors
- Anthony V Nicola (Advisor)Alan G Goodman (Committee Member)Michele E. Hardy (Committee Member)Hong Li (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- College of Veterinary Medicine
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 93
- Identifiers
- 99900581623901842
- Language
- English
- Resource Type
- Dissertation