Fig. 4: HNPs are present in BALF/sputum samples from A. baumannii-infected pneumonia patients.

A Schematic illustration of the BALF/sputum sample processing. BALF or sputum samples were diluted with 10 mM PBS, and centrifuged at 1000 × g, 4 °C for 10 min, then the supernatants were collected for further analysis. B Representative deconvolution of the mass spectrum of the sputum supernatant from the patient. Samples were analyzed using an Agilent 6230 LC-TOF system, and the mass spectrum was processed with Bioconfirm software (Agilent). Red arrows indicate the peaks corresponding to HNPs. C Quantification of HNP1 in the BALF/sputum supernatants by LC-MS. Extracted-ion chromatograms (EIC) for 1148 ± 1 m/z were used for calculating HNP1 levels based on peak areas. Synthetic HNP1 (10 – 10,000 nM) was used as the standard. D Quantification of HNP1-3 in BALF/sputum supernatants by ELISA. Results of C (n = 3 technical replicates for each patient sample) and D (n = 2 technical replicates for each patient sample) are presented as mean ± SD, representative of at least three independent experiments. See also Supplementary Fig. S6.