Journal: Science Advances
Article Title: Bacterial pathogens hijack host cell peroxisomes for replication vacuole expansion and integrity
doi: 10.1126/sciadv.adr8005
Figure Lengend Snippet: ( A ) S . Typhimurium growth is reduced in peroxisome-deficient cells. Wild-type (WT), PEX19-, and PEX5-deficient murine macrophages (RAW264.7 cells) were infected with WT S . Typhimurium ( St ) or an avirulent phoP - mutant strain. Bacterial growth was measured on the basis of recovered cfus from host cell lysates at 21 hpi, normalized to the WT strain in WT host cells by the number of intracellular bacteria at 2 hpi. Data are the mean ± SD of three biological replicates consisting of three technical replications each. An asterisk indicates a Student’s t test P < 0.05 compared to WT bacteria in WT host cells. ( B ) Defects in peroxisome function lead to more compact S . Typhimurium vacuoles. WT RAW264.7 cells or cells lacking functional peroxisomes ( Pex5 −/− ) were infected for 20 hours with S . Typhimurium constitutively expressing mCherry fluorescent protein, fixed, stained and visualized by fluorescence microscopy (left panel). The area of the vacuoles, based on the contour of the bacteria, and the number of bacteria within the vacuole, based on fluorescence intensity, were measured and the concentration of bacteria per vacuole (area/bacteria) was determined (right panels). Data are the combined measurements of three biological replicates, scoring 100 vacuoles per replicate. An asterisk indicates a two-tailed, nonparametric unpaired t test with Mann-Whitney correction P < 0.0001 relative to WT cells. ( C ) Peroxisome dysfunction leads to the destabilization of Salmonella -containing vacuoles (SCVs). Cells in (B) were stained for Galectin-3 (Gal3) (left panel) and the percentage of SCVs colocalizing with Galectin-3 were quantified (right panel). Data are the mean ± SD of three biological replicates consisting of three technical replications each, scoring 100 vacuoles per technical replicate. An asterisk indicates a Student’s t test P < 0.05 compared to WT cells.
Article Snippet: Equal amounts of protein were examined by Western analysis, probing with the target specific antibody, rabbit α-PEX5 (1:500) (Proteintech), rabbit α-GNPAT (1:1000) (Proteintech), or mouse α-AGPS (1:500) (Santa Cruz) overnight at 4°C, followed by HRP-conjugated α-rabbit IgG (1:5000) (Sigma-Aldrich) or HRP-conjugated α-mouse IgG (1:5000) (Sigma-Aldrich), as appropriate.
Techniques: Infection, Mutagenesis, Bacteria, Functional Assay, Expressing, Staining, Fluorescence, Microscopy, Concentration Assay, Two Tailed Test, MANN-WHITNEY