RT Journal Article
SR Electronic
T1 <em>In vivo</em> CRISPR screens identify GRA12 as a transcendent secreted virulence factor across <em>Toxoplasma gondii</em> strains and mouse subspecies
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2024.09.10.611481
DO 10.1101/2024.09.10.611481
A1 Torelli, Francesca
A1 Butterworth, Simon
A1 Lockyer, Eloise
A1 Song, Ok-Ryul
A1 Pearson-Farr, Jennifer
A1 Treeck, Moritz
YR 2024
UL http://biorxiv.org/content/early/2024/09/10/2024.09.10.611481.abstract
AB Toxoplasma gondii parasites exhibit extraordinary host promiscuity owing to over 250 putative secreted proteins that disrupt host cell functions, enabling parasite persistence. However, most of the known effector proteins are specific to Toxoplasma genotypes or hosts. To identify virulence factors that function across different parasite isolates and mouse strains that differ in susceptibility to infection, we performed systematic pooled in vivo CRISPR-Cas9 screens targeting the Toxoplasma secretome. We identified several proteins required for infection across parasite strains and mouse species, of which the dense granule protein 12 (GRA12) emerged as the most important effector protein during acute infection. GRA12 deletion in IFNγ-activated macrophages results in collapsed parasitophorous vacuoles and increased host cell necrosis, which is partially rescued by inhibiting early parasite egress. GRA12 orthologues from related coccidian parasites, including Neospora caninum and Hammondia hammondi, complement TgΔGRA12 in vitro, suggesting a common mechanism of protection from immune clearance by their hosts.Competing Interest StatementThe authors have declared no competing interest.