Format

Send to

Choose Destination
Cell. 2016 Sep 8;166(6):1423-1435.e12. doi: 10.1016/j.cell.2016.08.019. Epub 2016 Sep 2.

A Genome-wide CRISPR Screen in Toxoplasma Identifies Essential Apicomplexan Genes.

Author information

1
Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.
2
Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
3
Department of Microbiology and Immunology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA.
4
Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139 USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
5
Department of Pathology, Microbiology and Immunology, University of California, Davis, Davis, CA 95616, USA.
6
Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA. Electronic address: lourido@wi.mit.edu.

Abstract

Apicomplexan parasites are leading causes of human and livestock diseases such as malaria and toxoplasmosis, yet most of their genes remain uncharacterized. Here, we present the first genome-wide genetic screen of an apicomplexan. We adapted CRISPR/Cas9 to assess the contribution of each gene from the parasite Toxoplasma gondii during infection of human fibroblasts. Our analysis defines ∼200 previously uncharacterized, fitness-conferring genes unique to the phylum, from which 16 were investigated, revealing essential functions during infection of human cells. Secondary screens identify as an invasion factor the claudin-like apicomplexan microneme protein (CLAMP), which resembles mammalian tight-junction proteins and localizes to secretory organelles, making it critical to the initiation of infection. CLAMP is present throughout sequenced apicomplexan genomes and is essential during the asexual stages of the malaria parasite Plasmodium falciparum. These results provide broad-based functional information on T. gondii genes and will facilitate future approaches to expand the horizon of antiparasitic interventions.

KEYWORDS:

Apicomplexan parasites; eukaryotic pathogen; genome-wide CRISPR screen; host-cell invasion; host-pathogen interactions; malaria; toxoplasmosis

PMID:
27594426
PMCID:
PMC5017925
DOI:
10.1016/j.cell.2016.08.019
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center