# Viral use and mimicry of autophagy pathway and components

> **NIH NIH R01** · STANFORD UNIVERSITY · 2020 · $389,654

## Abstract

The long-term goals of this work are to determine the mechanisms by which components of the
autophagy pathway promote viral replication and spread and to identify targets for development
of non-toxic antiviral compounds. The canonical autophagy (self-eating) pathway, described by
recent Nobel Prize winner Yoshinori Ohsumi, is stimulated by nutrient deprivation and culminates
in the degradation of cytoplasmic contents, thus nourishing the starving cell. To this end,
dramatic cellular events such as massive lipid scavenging, growth of novel membranous
compartments, entrapment of cytoplasm by both concave and convex membrane curvature, and
fusion with lysosomes are accomplished within minutes. Numerous microbes, including
poliovirus and Dengue virus, have evolved to subvert segments of the cellular autophagy
pathway or its individual constituents to promote their infectious cycles. The precise individual
contributions of genes and proteins from autophagy pathways have not been identified for any of
these viruses. In the experiments proposed here, CRISPR/Cas9 technology will be used to
generate matched cell lines oblated for individual steps such as autophagy initiation, expansion
and curvature of the limiting membrane, and placement of crucial fusion protein LC3 on the
surface of the nascent autophagosome. Testing the effects of individual gene deletions on the
entry, translation, RNA replication and morphogenesis of poliovirus and dengue virus will reveal
which components of the autophagy pathway are usurped by these two representative positive-
strand RNA viruses.
The central hypothesis, based on preliminary results, is that poliovirus and dengue virus use
distinct steps and components of the cellular autophagy pathway for disparate purposes: RNA
replication and nonlytic spread for poliovirus, virion assembly and maturation for dengue virus.
The rationale of the proposed research is that, once the components and mechanisms of these
subversive events are identified, it will be feasible to target antiviral compounds to particular
molecules and processes. Not surprisingly, given the dependence of these viruses on autophagy
machinery, short periods of fasting greatly exacerbate pathogenesis in mouse models of both
poliovirus and dengue virus infection. This exacerbation is also observed in response to
commonly used medications known to stimulate autophagy. Rigorous genetic tests will be used
to determine whether this increased pathogenesis is indeed dependent on the cellular autophagy
pathway.

## Key facts

- **NIH application ID:** 9975099
- **Project number:** 5R01AI134912-03
- **Recipient organization:** STANFORD UNIVERSITY
- **Principal Investigator:** Karla Kirkegaard
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $389,654
- **Award type:** 5
- **Project period:** 2018-08-10 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9975099

## Citation

> US National Institutes of Health, RePORTER application 9975099, Viral use and mimicry of autophagy pathway and components (5R01AI134912-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9975099. Licensed CC0.

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