Caenorhabditis elegans defective-pharynx and constipated mutants are resistant to Orsay virus infection

TL;DR

Worms with a defective pharynx or defecation issues are resistant to Orsay virus infection, possibly due to changes in their gut environment.

Contribution

Identifies a novel link between gut physiology and antiviral resistance in C. elegans.

Findings

Defective-pharynx mutants show resistance to Orsay virus regardless of bacterial diet.

Defecation-defective mutants also exhibit Orsay virus resistance.

Resistance does not stem from constitutive antiviral gene expression.

Abstract

C.
elegans
animals with a compromised pharynx accumulate bacteria in their intestinal lumen and activate a transcriptional response that includes anti-bacterial response genes. In this study, we demonstrate that animals with defective pharynxes are resistant to Orsay virus (OrV) infection. This resistance is observed for animals grown on
Escherichia coli
OP50
and on
Comamonas
BIGb0172, a bacterium naturally associated with
C. elegans
. The viral resistance observed in defective-pharynx mutants does not seem to result from constitutive transcriptional immune responses against viruses. OrV resistance is also observed in mutants with defective defecation, which share with the pharynx-defective perturbations in the regulation of their intestinal contents and altered lipid metabolism. The underlying mechanisms of viral resistance in pharynx- and defecation-defective mutants remain elusive.

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