# Defining the cell and molecular basis of Toxoplasma recrudescence

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA RIVERSIDE · 2021 · $734,883

## Abstract

Project Summary
Reactivation of toxoplasmosis is a significant health threat to people chronically infected with
this parasite and is life-threatening to infected individuals that are or become
immunocompromised. Millions of people face this threat as it is estimated one third of human
populations are infected with this pathogen. Recrudescence of the Toxoplasma bradyzoite
tissue cyst is the cause of toxoplasmosis reactivation, which can not be prevented as there is no
current treatment that eliminates the dormant tissue cyst in chronically infected individuals.
Approaches to find therapeutic solutions to treat and prevent chronic toxoplasmosis have
suffered from limited accessibility to the relevant Toxoplasma stages and a lack of accurate in
vitro developmental models. Our goal in this proposal is to breakthrough these impasses. We
have developed a new innovative ex vivo model of bradyzoite recrudescence that we will utilize
to define the host cell specificity (Aim 1a), whole-cell gene expression (Aim 1b) and metabolic
changes (Aim 2) that unfold when a bradyzoite converts back to the tachyzoite and also in a
newly discovered alternate pathway where bradyzoites directly replicate to reform the tissue
cyst. This information is critically needed in order to understand how we might prevent
toxoplasmosis reactivation. The loss of developmental competency in vitro that is exacerbated
in current protocols producing transgenic strains is also a major impediment to understanding
the molecular basis of tissue cyst reactivation. In this proposal, we will implement and optimize
an innovative approach to generate developmentally competent transgenic strains (Aim 3a), and
use this new protocol to define cyclin and other protein mechanisms (Aim 3b) that have critical
roles in regulating bradyzoite recrudescence and tissue cyst re-formation

## Key facts

- **NIH application ID:** 10180280
- **Project number:** 1R01AI158417-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA RIVERSIDE
- **Principal Investigator:** Michael W White
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $734,883
- **Award type:** 1
- **Project period:** 2021-01-15 → 2025-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10180280

## Citation

> US National Institutes of Health, RePORTER application 10180280, Defining the cell and molecular basis of Toxoplasma recrudescence (1R01AI158417-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10180280. Licensed CC0.

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