Fig. 2

a Increase of A. phagocytophilum 16S rRNA relative to murine HPRT mRNA at different time points p.i. of MPO^−/−, iNOS^−/−, gp91phox^−/− and wild-type (WT) neutrophils. Results were normalised to the respective 0 h value of each sample using the ΔΔC_t-method. Mean and SD from 7 independent experiments are shown. Differences between experimental groups were analysed using the two-tailed Mann-Whitney test. The following groups were compared: WT and MPO^−/−, iNOS^−/−, gp91phox^−/− neutrophils, respectively at each time point. Statistically significant differences were not detected. b, c Nitrite accumulation as a marker for iNOS activity in the supernatants of A. phagocytophilum-infected (b) or LPS-stimulated (10 ng/ml) (c) WT, gp91^phox−/− and MPO^−/− Hoxb8 neutrophils measured by Griess assay. Nitrite production could not be detected in all uninfected samples or in iNOS^−/− cells (data not shown). Mean and SD from 7 independent experiments are presented. Differences between experimental groups were analysed using the two-tailed Mann-Whitney test. Infected and LPS-stimulated WT Hoxb8 neutrophils were compared to the respective gp91^phox−/− and MPO^−/− cells at each time point. *P < 0.05, **P < 0.01