Figure 4

Figure 4

GW633459A is an inhibitor of the HER kinase family and reduces intracellular MRSA burden, but probably through a mechanism unrelated to these host kinase targets. (A) Chemical structure of GW633459A. (B, C) GW633459A was tested at different concentrations to determine its antimicrobial potency (B) and level of cytotoxicity (C) in MRSA-infected HeLa cells. (D) The KinMap kinase phylogenetic tree shows the kinase inhibition profile of GW633459A as determined by Caliper assay (Elkins et al., 2016). Each circle represents a kinase target that is inhibited > 50% at 0.1 µM (purple) or 1 µM (blue) concentration. Only the tyrosine kinase (TK) branch of the phylogenetic tree contains targets of GW633459A. (E, F) Baseline expression of the HER kinase family in HeLa cells was determined by flow cytometry after surface staining (E) or intracellular staining (F). Kinase expression is shown in purple and isotype controls are shows in grey. (G) Chemical structure of lapatinib. (H, I) Lapatinib was tested at different concentrations to determine its antimicrobial potency (H) and level of cytotoxicity (I) in MRSA-infected HeLa cells. (J) Chemical structure of sapitinib. (K, L) Sapitinib was tested at different concentrations to determine its antimicrobial potency (K) and level of cytotoxicity (L) in MRSA-infected HeLa cells. Bars and error bars show the median ± interquartile range. Each datapoint represents the results of an independent experiment. Statistical significance of observed differences was tested in comparison to the DMSO controls using Friedman tests.