Host genetics highlights IFN-γ-dependent Toxoplasma genes encoding secreted and non-secreted virulence factors in in vivo CRISPR screens

Cell Rep. 2023 Jun 27;42(6):112592. doi: 10.1016/j.celrep.2023.112592. Epub 2023 Jun 1.

Abstract

Secreted virulence factors of Toxoplasma to survive in immune-competent hosts have been extensively explored by classical genetics and in vivo CRISPR screen methods, whereas their requirements in immune-deficient hosts are incompletely understood. Those of non-secreted virulence factors are further enigmatic. Here we develop an in vivo CRISPR screen system to enrich not only secreted but also non-secreted virulence factors in virulent Toxoplasma-infected C57BL/6 mice. Notably, combined usage of immune-deficient Ifngr1-/- mice highlights genes encoding various non-secreted proteins as well as well-known effectors such as ROP5, ROP18, GRA12, and GRA45 as interferon-γ (IFN-γ)-dependent virulence genes. The screen results suggest a role of GRA72 for normal GRA17/GRA23 localization and the IFN-γ-dependent role of UFMylation-related genes. Collectively, our study demonstrates that host genetics can complement in vivo CRISPR screens to highlight genes encoding IFN-γ-dependent secreted and non-secreted virulence factors in Toxoplasma.

Keywords: CP: Immunology; CP: Microbiology; IFN-γ; Toxoplasma; UFMylation; apicomplexa; host genetics; host-pathogen interaction; in vivo CRISPR screen; parasitophorous vacuole membrane; virulence genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Clustered Regularly Interspaced Short Palindromic Repeats / genetics
  • Interferon-gamma / genetics
  • Mice
  • Mice, Inbred C57BL
  • Protozoan Proteins / genetics
  • Toxoplasma* / metabolism
  • Virulence Factors* / genetics
  • Virulence Factors* / metabolism

Substances

  • Virulence Factors
  • Interferon-gamma
  • Protozoan Proteins