Figure 3 | Laboratory Investigation

Figure 3

From: Detergent-resistant microdomains mediate activation of host cell signaling in response to attaching–effacing bacteria

Figure 3

Intact lipid microdomains are required for EHEC-induced translocation of phosphoinositide 3-kinase (PI3K) to lipid rafts, whereas secreted bacterial factors are insufficient to induce this recruitment. Conditioned medium did not induce the recruitment of PI3K to lipid microdomains on host cell membranes (a). Disruption of lipid rafts by depleting cellular cholesterol using MβCD (10 mM) leads to decreased recruitment of the host signaling protein, PI3K, in response to EHEC O157:H7 infection. Culture supernatant alone was unable to induce recruitment of PI3K (b). Phosphorylation of the PI3K downstream effector Akt was not detected in response to EHEC and C. rodentium infections (c, d), suggesting an alternative activated pathway. Lipid raft disruption after cholesterol-depleting MβCD treatment was visualized using Alexa fluor 594-labeled cholera toxin subunit B: untreated cells (e and f), MβCD-treated cells (g, h), and MβCD-treated epithelia replenished with soluble cholesterol (i, j).

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