Transcriptional repression by ApiAP2 factors is central to chronic toxoplasmosis

Joshua B. Radke, Danielle Worth, David Hong, Sherri Huang, William J. Sullivan, Emma H. Wilson, Michael W. White

Research output: Contribution to journalArticle

19 Scopus citations


Tachyzoite to bradyzoite development in Toxoplasma is marked by major changes in gene expression resulting in a parasite that expresses a new repertoire of surface antigens hidden inside a modified parasitophorous vacuole called the tissue cyst. The factors that control this important life cycle transition are not well understood. Here we describe an important transcriptional repressor mechanism controlling bradyzoite differentiation that operates in the tachyzoite stage. The ApiAP2 factor, AP2IV-4, is a nuclear factor dynamically expressed in late S phase through mitosis/cytokinesis of the tachyzoite cell cycle. Remarkably, deletion of the AP2IV-4 locus resulted in the expression of a subset of bradyzoite-specific proteins in replicating tachyzoites that included tissue cyst wall components BPK1, MCP4, CST1 and the surface antigen SRS9. In the murine animal model, the mis-timing of bradyzoite antigens in tachyzoites lacking AP2IV-4 caused a potent inflammatory monocyte immune response that effectively eliminated this parasite and prevented tissue cyst formation in mouse brain tissue. Altogether, these results indicate that suppression of bradyzoite antigens by AP2IV-4 during acute infection is required for Toxoplasma to successfully establish a chronic infection in the immune-competent host.

Original languageEnglish (US)
Article numbere1007035
JournalPLoS pathogens
Issue number5
StatePublished - May 2018

ASJC Scopus subject areas

  • Parasitology
  • Microbiology
  • Immunology
  • Molecular Biology
  • Genetics
  • Virology

Fingerprint Dive into the research topics of 'Transcriptional repression by ApiAP2 factors is central to chronic toxoplasmosis'. Together they form a unique fingerprint.

  • Cite this

    Radke, J. B., Worth, D., Hong, D., Huang, S., Sullivan, W. J., Wilson, E. H., & White, M. W. (2018). Transcriptional repression by ApiAP2 factors is central to chronic toxoplasmosis. PLoS pathogens, 14(5), [e1007035].