Infection and Cystic Fibrosis Unit, San Raffaele Scientific Institute, Milano, Italy, Istituto di Chimica e Tecnologia dei Polimeri - ICTP - CNR, Via P. Gaifami 18, 95126 Catania, Italy, Dipartimento di Scienze Chimiche, Universita di Napoli 'Federico II', Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Napoli, Italy
Pseudomonas aeruginosa, the major pathogen involved in lethal infections in cystic fibrosis (CF) population, is able to cause permanent chronic infections that can persist over the years. This ability to chronic colonize CF airways is related to a series of adaptive bacterial changes involving the immunostimulant lipopolysaccharide (LPS) molecule. The structure of LPSs isolated from several P. aeruginosa strains showed conserved features that can undergo chemical changes during the establishment of the chronic infection. In the present paper, we report the elucidation of the structure and the biological activity of the R-LPS (lipooligosaccharide, LOS) isolated from the persistent CF isolate P. aeruginosa strain RP73, in order to give further insights in the adaptation mechanism of the pathogen in the CF environment. The complete structural analysis of P. aeruginosa RP73 LOS was achieved by chemical analyses, NMR spectroscopy and MALDI MS spectrometry, while the assessment of the biological activity was attained testing the in vivo pro-inflammatory capacity of the isolated LOS molecule. While a typical CF LPS is able to trigger a high immune response and production of pro-inflammatory molecules, this P. aeruginosa RP73 LOS showed to possess a low pro-inflammatory capacity. This was possible due to a singular chemical structure possessing an under-acylated lipid A very similar to the LPS of P. aeruginosa found in chronic lung diseases such as bronchiectstasis.
13C NMR, 1H NMR, methylation, NMR-2D, GC-MS, SDS-PAGE, chemical analysis, ELISA, 31P NMR, mild acid hydrolysis, GC, MS/MS, MALDI-TOF MS, biological assays, de-O-acylation with hydrazine, NMR-1D, methanolysis, GPC, de-N-acylation, acetylation
tested in vivo pro-inflammatory effect of the LOS from P. aeruginosa RP73
NMR data for terminal aLRhap residue, 1H: 5.03 4.18 3.67 3.33 3.89 1.15, 13C: 102.2 69.9 70.1 71.8 71.8 16.4.
13C NMR data:
Linkage Residue C1 C2 C3 C4 C5 C6 C7 C8
0,6,6,4 aXKdo? 174.4 101.7 34.9 65.6 66.6 70.1 ? 62.7
0,6,6,5,3,3,3,3,3 %bDQuipN 100.9 56.6 74.2 73.2 75.2 16.9
0,6,6,5,3,3,3,3 aLRhap 100.5 73.0 80.1 72.4 71.0 16.4
0,6,6,5,3,3,3,6 aDGlcp 97.9 73.0 73.5 69.6 72.1 60.7
0,6,6,5,3,3,3 bDGlcp 104.3 73.5 82.0 68.2 74.3 66.3
0,6,6,5,3,3,4 aDGlcp 99.1 71.7 72.3 ? 71.2 59.8
0,6,6,5,3,3 aDGalpN 96.5 50.4 76.5 75.4 71.8 61.7
0,6,6,5,3,4 P
0,6,6,5,3,6 P
0,6,6,5,3 aXLDmanHepp 101.9 69.3 76.5 72.5 68.8 70.0 63.5
0,6,6,5,2 P
0,6,6,5,4 P
0,6,6,5 aXLDmanHepp 97.3 74.3 73.7 72.3 74.2 71.2 63.5
0,6,6 aXKdo? 174.4 101.7 34.3 71.0 68.2 69.5 ? 63.0
0,6,4 %xXP?
0,6 bDGlcpN 99.3 55.4 72.3 73.8 ? 62.5
0 aDGlcpN 90.5 54.4 69.4 69.6 72.4 69.3
P
1H NMR data:
Linkage Residue H1 H2 H3 H4 H5 H6 H7 H8
0,6,6,4 aXKdo? - - 1.67-1.96 4.05 3.96 3.66 ? 3.58
0,6,6,5,3,3,3,3,3 %bDQuipN 4.84 2.99 3.53 3.18 3.38 1.30
0,6,6,5,3,3,3,3 aLRhap 5.03 3.37 3.89 3.63 4.02 1.14
0,6,6,5,3,3,3,6 aDGlcp 4.89 3.45 3.72 3.36 3.67 3.61
0,6,6,5,3,3,3 bDGlcp 4.55 3.33 3.54 3.57 3.57 3.71-3.77
0,6,6,5,3,3,4 aDGlcp 4.91 3.38 3.72 3.64 3.95 3.78
0,6,6,5,3,3 aDGalpN 5.49 3.71 4.34 4.38 4.34 3.66
0,6,6,5,3,4 P
0,6,6,5,3,6 P
0,6,6,5,3 aXLDmanHepp 5.08 4.30 4.13 4.08 4.02 4.31 3.52-3.78
0,6,6,5,2 P
0,6,6,5,4 P
0,6,6,5 aXLDmanHepp 5.24 4.40 4.05 4.22 4.29 3.95 3.52-3.78
0,6,6 aXKdo? - - 1.88-2.11 4.00 4.16 3.72 ? 3.67
0,6,4 %xXP?
0,6 bDGlcpN 4.75 2.93 3.72 3.61 ? 3.34
0 aDGlcpN 5.53 3.30 3.78 3.49 4.04 3.65-4.18
P
1H/13C HSQC data:
Linkage Residue C1/H1 C2/H2 C3/H3 C4/H4 C5/H5 C6/H6 C7/H7 C8/H8
0,6,6,4 aXKdo? 34.9/1.67-1.96 65.6/4.05 66.6/3.96 70.1/3.66 ?/? 62.7/3.58
0,6,6,5,3,3,3,3,3 %bDQuipN 100.9/4.84 56.6/2.99 74.2/3.53 73.2/3.18 75.2/3.38 16.9/1.30
0,6,6,5,3,3,3,3 aLRhap 100.5/5.03 73.0/3.37 80.1/3.89 72.4/3.63 71.0/4.02 16.4/1.14
0,6,6,5,3,3,3,6 aDGlcp 97.9/4.89 73.0/3.45 73.5/3.72 69.6/3.36 72.1/3.67 60.7/3.61
0,6,6,5,3,3,3 bDGlcp 104.3/4.55 73.5/3.33 82.0/3.54 68.2/3.57 74.3/3.57 66.3/3.71-3.77
0,6,6,5,3,3,4 aDGlcp 99.1/4.91 71.7/3.38 72.3/3.72 ?/3.64 71.2/3.95 59.8/3.78
0,6,6,5,3,3 aDGalpN 96.5/5.49 50.4/3.71 76.5/4.34 75.4/4.38 71.8/4.34 61.7/3.66
0,6,6,5,3,4 P
0,6,6,5,3,6 P
0,6,6,5,3 aXLDmanHepp 101.9/5.08 69.3/4.30 76.5/4.13 72.5/4.08 68.8/4.02 70.0/4.31 63.5/3.52-3.78
0,6,6,5,2 P
0,6,6,5,4 P
0,6,6,5 aXLDmanHepp 97.3/5.24 74.3/4.40 73.7/4.05 72.3/4.22 74.2/4.29 71.2/3.95 63.5/3.52-3.78
0,6,6 aXKdo? 34.3/1.88-2.11 71.0/4.00 68.2/4.16 69.5/3.72 ?/? 63.0/3.67
0,6,4 %xXP?
0,6 bDGlcpN 99.3/4.75 55.4/2.93 72.3/3.72 73.8/3.61 ?/? 62.5/3.34
0 aDGlcpN 90.5/5.53 54.4/3.30 69.4/3.78 69.6/3.49 72.4/4.04 69.3/3.65-4.18
P
report error
Found 1 record.
Displayed record 1
]; cancer [ICD11: 2D4Z 
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