IFNs Modify the Proteome of Legionella-Containing Vacuoles and Restrict Infection Via IRG1-Derived Itaconic Acid
Fig 3
Type I and II IFNs alter the protein composition of LCVs.
(A) Proteomic analysis of LCVs isolated 2 h p.i. from untreated BMMs infected with L. pneumophila ΔflaA detected 2854 proteins in all six replicates of which 2307 were identified as host- and 547 as L. pneumophila-derived. (B) GO enrichment analysis for overrepresented cellular components of the host proteins was done and overrepresented child terms of GO:0043231 ‘intracellular membrane-bounded organelle’ were extracted. Depicted are p-values for the indicated GO terms as well as the number of identified proteins annotated with each term; # no p-value for GO term ‘nucleus’ was computed. (C-E) Quantitative proteomic analysis of LCVs isolated 2 h p.i. with L. pneumophila ΔflaA from BMMs left untreated or treated with 50 U/ml IFNβ or IFNγ 16–18 h prior to and during infection. Volcano plots show unchanged proteins (grey) and proteins with a significant higher (red) or lower (green) abundance at LCVs from IFNβ- (C) or IFNγ- (D) treated BMMs compared to untreated cells, and direct comparison of IFNβ- versus IFNγ-treated samples (E). See also S6 Fig for detailed list of top 20 proteins for each condition. Proteomic analysis was done from 6 (untreated), 5 (IFNγ) and 4 (IFNβ) individual LCV isolations.