Figure 1. CRISPR-Cas9 knockout screens for modifiers of L. pneumophila pathogenesis.

(A) U937 cell killing by L. pneumophila. U937 cells were infected with the indicated MOI of WT or ΔdotA L. pneumophila and live cells were counted 24 hours after infection using flow cytometry and compared between strains (n = 2 technical replicates, two-tailed Student’s t test, **P<0.01; error bars, s.d.

(B) Schematic of screen. Cas9-expressing U937 cells were infected with a genome-wide lentiviral sgRNA library. Half of the population was treated with 5 rounds of L. pneumophila infection while the other half was maintained in log-phase growth before quantification by deep sequencing.

(C) Volcano plot of confidence score vs. effect size for all genes. Blue dots indicate genes whose knockout protect host cells from L. pneumophila infection and red dots indicate genes whose knockout sensitize host cells to L. pneumophila infection using a 10% FDR cutoff. Genome-wide screen results are in Table S1.

(D) Adjusted P values for select non-redundant enriched gene-ontology (GO) terms using GOrilla on a ranked list of genome-wide screen hits.

(E) Schematic of genes included in batch retest library. Genes in batch retest library are listed in Table S2.

(F) Correlation of signed confidence scores between genome-wide and batch retest screens.

See also Figure S1.