Herpes simplex virus (HSV) causes lifelong latent infections in humans. It is responsible for significant disease, ranging from cold sores and genital infections to neonatal infections, blindness and fatal encephalitis. The long-term goal of this project is to understand the molecular mechanisms that HSV uses to gain entry into host cells. Herpesvirus membrane fusion and entry is a complex cascade of interactions involving multiple viral glycoproteins and multiple cellular triggers. An emerging concept in herpesvirology is that the endosomal pH of the host cell is required for viral entry, often in a cell type specifi manner. The mechanistic role that low pH plays is not clear. We recently identified HSV envelope glycoprotein B (gB) as the principal target of endosomal pH. Mildly acidic pH reversibly alters the antigenic structure and oligomeric conformation of gB in vitro and during virus entry into cells. Based on these newly identified conformational changes, we propose to develop herpesviral entry inhibitors and to elucidate the role of gB in driving the fusion reaction In Specific Aim # 1, we will test the hypothesis that gB conformation change is a novel target for antiviral intervention. We will identify specific and potent peptide inhibitors of gB structural transition. Inhibitors will be assessed for the ability to block viral membrane fusion and entry.
I Specific Aim # 2, we will define the contribution of the gB cytoplasmic tail to its conformation change and membrane fusion. Our experimental design employs techniques of cell biology, biochemistry, and molecular virology. HSV utilizes a pH-dependent endocytosis pathway in epithelial cells, the initial portal of entry in the human host. Thus, achieving these aims will delineate a key step in the mechanism of the initial infection of target cells and reveal a means to prevent it. The results will provide a mechanistic understanding of conformational change in gB and its relation to membrane fusion.

Public Health Relevance

Herpes simplex virus infections are common in humans and can cause serious complications such as neonatal disease, blindness and fatal encephalitis. This research concerns how the herpesvirus initiates infection in humans by studying the entry of virus into host cells at the molecular level. Greater understanding of how this process works will help to develop novel anti-viral approaches for preventing herpes infections.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AI096103-02
Application #
8501355
Study Section
Virology - B Study Section (VIRB)
Program Officer
Challberg, Mark D
Project Start
2012-07-01
Project End
2014-06-30
Budget Start
2013-07-01
Budget End
2014-06-30
Support Year
2
Fiscal Year
2013
Total Cost
$177,425
Indirect Cost
$59,925
Name
Washington State University
Department
Veterinary Sciences
Type
Schools of Veterinary Medicine
DUNS #
041485301
City
Pullman
State
WA
Country
United States
Zip Code
99164
Wudiri, George A; Pritchard, Suzanne M; Li, Hong et al. (2014) Molecular requirement for sterols in herpes simplex virus entry and infectivity. J Virol 88:13918-22
Komala Sari, Tri; Pritchard, Suzanne M; Cunha, Cristina W et al. (2013) Contributions of herpes simplex virus 1 envelope proteins to entry by endocytosis. J Virol 87:13922-6
Pritchard, Suzanne M; Cunha, Cristina W; Nicola, Anthony V (2013) Analysis of herpes simplex virion tegument ICP4 derived from infected cells and ICP4-expressing cells. PLoS One 8:e70889
Lu, Xiaonan; Liu, Qian; Benavides-Montano, Javier A et al. (2013) Detection of receptor-induced glycoprotein conformational changes on enveloped virions by using confocal micro-Raman spectroscopy. J Virol 87:3130-42
Barrow, Eric; Nicola, Anthony V; Liu, Jin (2013) Multiscale perspectives of virus entry via endocytosis. Virol J 10:177