Iminosugars with endoplasmic reticulum alpha-glucosidase inhibitor activity are potent inhibitors of Zika virus replication in vitro

Open Access
- Author:
- Bhushan, Gitanjali L
- Graduate Program:
- Pathobiology
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- October 09, 2018
- Committee Members:
- Suresh Varma Kuchipudi, Thesis Advisor/Co-Advisor
Anthony Paul Schmitt, Committee Member
Troy Clavell Sutton, Committee Member
Santhosh Girirajan, Committee Member - Keywords:
- Zika virus
antiviral - Abstract:
- Zika virus (ZIKV) is a vector-borne virus of the family Flaviviridae, which continues to spread and remains a major global public health threat. Currently, there are no approved vaccines or antivirals against ZIKV. In this study, the anti-ZIKV ability of four iminosugars with endoplasmic reticulum α- glucosidase inhibitor (ER-AGI) activity namely, deoxynojirimycin (DNJ), N-nonyl deoxynojirimycin (NN-DNJ), castanospermine and celgosivir were investigated. None of the four ER-AGIs showed any significant (p>0.05) cytotoxicity in Vero and human microglia (CHME-3) cells from 0.01 M to 100 M concentrations. Iminosugar treatment of Vero or CHME-3 cells infected with ZIKV at a MOI of 0.5 or 5 resulted in significant inhibition of ZIKV replication and the reduction in ZIKV replication was not associated with any significant change in the expression levels of key antiviral genes. Iminosugars protect cells from ZIKV cytopathogenicity as iminosugar treated Vero and CHME-3 cells showed little or no cell death, whereas vehicle control cells exhibited 50-60% cytopathic effect (CPE) at 72 h following ZIKV infection. We further investigated if CPE was the result of apoptosis and/or necrosis. The difference in apoptosis was measured using an activated caspase 3 and 7 assay, and necrosis was evaluated by using a lactate dehydrogenase (LDH) assay in iminosugar treated and control cells following ZIKV infection at a MOI of 1. There was no difference in apoptosis between iminosugar treated and control cells at 48 and 72 hours post infection (hpi). Unlike iminosugars treated cells, untreated control cells exhibited substantial elevation of necrosis at 72 hpi compared with mock-infected cells. In summary, iminosugars with ER-AGI function inhibit ZIKV replication without altering the antiviral gene expression of human cells. The results of this study strongly suggest that ER-AGIs are promising anti-ZIKV antiviral agents and such warrant further in vivo studies.