Document Type

Thesis - Open Access

Award Date

2018

Degree Name

Master of Science (MS)

Department

Biology and Microbiology

First Advisor

Xiuqing Wang

Keywords

Antiviral, G3BP1, PEDV, Stress granules

Abstract

Porcine Epidemic Diarrhea Virus (PEDV) is a non-segmented virus which uses one-stranded, positive-sense RNA as genetic material. PEDV falls under Coronaviridae family and extensive diarrhea and dehydration in nursing piglets are the major clinical signs. This emerging disease leads to huge economic loss in the pig farming. Very less studies are done towards the role of innate immunity in PEDV infection. The formation of Stress granules (SGs) are seen when cells are introduced to different stressful conditions, which also includes viral infections. SGs are formed when one of the four kinases: doublestranded RNA (dsRNA)-dependent protein kinase (PKR), PKR-like endoplasmic reticulum kinase (PERK), general control nonderepressible 2 (GCN2) kinase and hemeregulated inhibitor kinase (HRI), causes phosphorylation of eukaryotic translation initiation factor (eIF2α). The alternative pathway of SG formation is eIF4A RNA helicase inhibition. Phosphorylation of eIF2α by PKR activation is the most common pathway of SGs formation. SGs are considered as an indication of an antiviral innate response of the host that limits translation of the viral genes. Ras-GTPase-activating protein (SH3 domain) binding protein 1 (G3BP1) is one of the important stress granule-resident protein that nucleates stress granule assembly. The objective of the study was to investigate the role of G3BP1 in PEDV replication. We found that depletion of G3BP1 inhibits SGs formation and overexpression of G3BP1 nucleates SGs assembly. We observed that knockdown of G3BP1 by silencing RNA significantly increased PEDV replication. Similarly, overexpression of exogenous G3BP1 lowered virus replication by approximately 100-fold compared to vector control. We also observed that PEDV-infected cells are resistant to SGs formation upon sodium arsenite treatment. An enhancement in the levels of mRNAs of pro-inflammatory cytokines such as interleukin-1β (IL-1β) and tumor necrosis factor - α (TNF-α) was also observed in PEDV-infected G3BP1 knockdown cells compared to PEDV-infected control cells. Taken together, our results demonstrate that PEDV induces transient SGs formation and G3BP1 plays an antiviral role in virus replication.

Description

Includes bibliographical references

Format

application/pdf

Number of Pages

61

Publisher

South Dakota State University

Rights

In Copyright - Non-Commercial Use Permitted
http://rightsstatements.org/vocab/InC-NC/1.0/

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