# Antiviral Discovery in Microbial Eukaryotes

> **NIH NIH DP2** · UNIVERSITY OF WASHINGTON · 2024 · $477,226

## Abstract

Project Summary
Antiviral systems are critical to the survival of their host. They protect from virally induced morbidity and mortality
across all known domains of life and play an essential role in controlling the endogenized viral elements
contained in genomes, the unchecked expression of which can lead to debilitating autoimmune diseases in
humans and developmental problems in multicellular organisms. Many antiviral systems encode the exquisite
ability to detect and modify or destroy specific nucleic acids, and this has made those components transformative
tools for biotechnology and medicine. The directed discovery of antiviral systems in prokaryotes has exploded
the number of antiviral systems that were known and reshaped how we think about the evolution of antiviral
immune strategies. In eukaryotes, far less discovery research has been done even though there is significant
lack of conservation between the well-studied antiviral systems of humans, plants, and insects with those of
microbial eukaryotes such as amoeba. Not only are microbial eukaryotes the most abundant eukaryote, but they
are also often hosts of the most enigmatic viruses discovered to date, the Megavirales family; giant viruses
whose physical and genome size can rival that of bacteria. The machinery these microbial hosts use to control
viral infection, and how these viruses subvert these responses remains almost entirely unknown. This proposal
aims to address this unanswered question through first understanding how Acanthamoeba spp. defend
themselves against members of the Megavirales family before expanding that understanding (and the tools used
to arrive at it) to other microbial eukaryotes. We will combine principles of the virus-host arms race with cutting-
edge AI-driven protein structure prediction and homology detection to uncover viral proteins that are involved in
antagonizing currently known pathways of viral restriction in Acanthamoeba. We will further use environmental
sampling to establish a collection of viruses and wild amoeba isolates that display a range of susceptibilities to
our giant viruses to identify new systems of restriction within the Acanthamoeba genus. Finally, we will combine
our environmental sampling with discovery-based functional metatranscriptomics to realize the hidden antiviral
capacity of the abundant microbial eukaryotes. Ultimately, these discoveries will lead to the first comprehensive
assessment of non-metazoan antiviral systems that are present in eukaryotes. This will not only dramatically
expand our knowledge and challenge ideas of how eukaryotic antiviral systems evolved, but the results of this
proposal will provide new molecules that can be used to better human life and life quality through their
technological and direct biomedical applications, as have so many antiviral systems before.

## Key facts

- **NIH application ID:** 10947358
- **Project number:** 1DP2AI184554-01
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** Tristan Xavier Jordan
- **Activity code:** DP2 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $477,226
- **Award type:** 1
- **Project period:** 2024-08-14 → 2029-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10947358

## Citation

> US National Institutes of Health, RePORTER application 10947358, Antiviral Discovery in Microbial Eukaryotes (1DP2AI184554-01). Retrieved via AI Analytics 2026-06-12 from https://api.ai-analytics.org/grant/nih/10947358. Licensed CC0.

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