Dynamic microtubules participate in the formation of the CCV.

HeLa cells were infected for 16 h with Coxiella burnetii and incubated for 48 h with either DMSO (control), taxol or nocodazole. Cells were then fixed and processed for IIF. Mts were labelled with an anti-α tubulin antibody (green pseudo-colour) or C. burnetii with a specific antibody (red pseudo-colour). (A) Cells treated with 0.1% DMSO (panel a-d), 2 μM taxol (panel e-h), and 2 μM nocodazole (Noc) (panel i-l). Scale bar: 10 μm. Quantitative analysis of CCV size (B) and number (C)s, and bacterial multiplication (D). Forty to sixty cells were analysed in each experiment. Results are expressed as means ± SE of three independent experiments. ***p<0.001. (E) Phase contrast microscopy of infected and transfected HeLa cells. Arrowheads indicate a nrCCV (panel b and c), or a CCV (panel a). Scale bar: 2 μm.