Journal:

Article Title: Human Neutrophil Chemotaxis Is Modulated by Capsule and O Antigen from an Extraintestinal Pathogenic Escherichia coli Strain

doi: 10.1128/IAI.71.11.6435-6445.2003

Figure Lengend Snippet: Linearity of the in vitro neutrophil chemotaxis assay in response to live E. coli CP9 (wild type), CP921 (O-antigen deficient), and CP9.137 (capsule deficient). A total of 5 × 105 purified human neutrophils was placed in the upper well of a chemotaxis chamber, with various titers of CP9, CP921, and CP9.137 placed in the lower chamber. Neutrophils that migrated into the lower chamber (following incubation at 37°C for 30 min) in response to the E. coli were quantitated by flow cytometry. Results demonstrate that this chemotaxis assay was linear from 3 × 106 to 1 × 108 CFU of E. coli (R2 = 0.97, 0.95, and 0.96 for CP9, CP921, and CP9.137, respectively).

Article Snippet: Neutrophil chemotaxis toward cell-free culture supernatants was primarily N -t-BOC sensitive (100, 97.4, and 96% for CP9, CP921, and CP9.137, respectively); therefore, N -t-BOC-insensitive chemotaxis toward cell-free culture supernatants is not shown.

Techniques: In Vitro, Chemotaxis Assay, Purification, Incubation, Flow Cytometry

Journal:

Article Title: Human Neutrophil Chemotaxis Is Modulated by Capsule and O Antigen from an Extraintestinal Pathogenic Escherichia coli Strain

doi: 10.1128/IAI.71.11.6435-6445.2003

Figure Lengend Snippet: Inhibition of FMLP-mediated chemotaxis by N-t-BOC. A total of 5 × 105 purified human neutrophils was placed in the upper well of a chemotaxis chamber with various concentrations of N-t-BOC (0 to 800 μM) and an antagonist of the high-affinity FPR. FMLP (50 nM) was placed in the lower chamber. Greater than 95% inhibition of FMLP-mediated chemotaxis occurred with the use of concentrations of N-t-BOC that were greater than 400 μM.

Article Snippet: Neutrophil chemotaxis toward cell-free culture supernatants was primarily N -t-BOC sensitive (100, 97.4, and 96% for CP9, CP921, and CP9.137, respectively); therefore, N -t-BOC-insensitive chemotaxis toward cell-free culture supernatants is not shown.

Techniques: Inhibition, Chemotaxis Assay, Purification

Journal:

Article Title: Human Neutrophil Chemotaxis Is Modulated by Capsule and O Antigen from an Extraintestinal Pathogenic Escherichia coli Strain

doi: 10.1128/IAI.71.11.6435-6445.2003

Figure Lengend Snippet: In vitro chemotaxis of human neutrophils in response to live E. coli CP9 (wild type) and cell-free culture supernatant from CP9. The total deduced N-t-BOC-sensitive and the N-t-BOC-insensitive chemotaxis indices are depicted (see Materials and Methods for details on these indices). When the positive control (FMLP, 50 nM) with or without N-t-BOC was used as the chemoattractant, neutrophil chemotaxis was expressed as numbers of neutrophil events. The neutrophil response to the positive control (FMLP, 50 nM) was 30,920 ± 2,733 (mean ± SEM), of which 95% ± 1.5% was inhibited by N-t-BOC (500 μM) (number of samples, 14; data not shown on graph). Neutrophil chemotaxis toward the wild-type E. coli strain was both N-t-BOC sensitive and insensitive. In contrast, only N-t-BOC-sensitive chemotaxis was observed toward cell-free culture supernatant from the wild-type E. coli strain.

Article Snippet: Neutrophil chemotaxis toward cell-free culture supernatants was primarily N -t-BOC sensitive (100, 97.4, and 96% for CP9, CP921, and CP9.137, respectively); therefore, N -t-BOC-insensitive chemotaxis toward cell-free culture supernatants is not shown.

Techniques: In Vitro, Chemotaxis Assay, Positive Control

Journal:

Article Title: Human Neutrophil Chemotaxis Is Modulated by Capsule and O Antigen from an Extraintestinal Pathogenic Escherichia coli Strain

doi: 10.1128/IAI.71.11.6435-6445.2003

Figure Lengend Snippet: Measurement of TNF-α and IL-8 levels in an in vitro chemotaxis assay

Article Snippet: Neutrophil chemotaxis toward cell-free culture supernatants was primarily N -t-BOC sensitive (100, 97.4, and 96% for CP9, CP921, and CP9.137, respectively); therefore, N -t-BOC-insensitive chemotaxis toward cell-free culture supernatants is not shown.

Techniques: In Vitro, Chemotaxis Assay

Journal:

Article Title: Human Neutrophil Chemotaxis Is Modulated by Capsule and O Antigen from an Extraintestinal Pathogenic Escherichia coli Strain

doi: 10.1128/IAI.71.11.6435-6445.2003

Figure Lengend Snippet: In vitro chemotaxis of human neutrophils in response to the live E. coli strains CP9 (wild type), CP921 (O-antigen deficient), and CP9.137 (capsule deficient) and to cell-free culture supernatant from CP9, CP921, and CP9.137. The total deduced N-t-BOC-sensitive and the N-t-BOC-insensitive chemotaxis indices are depicted (see Materials and Methods for details on these indices). The neutrophil response to the positive control (FMLP, 50 nM) was 30,920 ± 2,733 (mean ± SEM), of which 95% ± 1.5% was inhibited by N-t-BOC (500 μM) (n = 14; data not shown in graph). Total chemotaxis was significantly decreased toward the wild-type E. coli strain that possessed an O antigen and capsule (CP9) compared to the isogenic O-antigen-deficient derivatives (CP921) (*, P = 0.002 compared to CP9, paired t test; n = 14 for each strain), and total chemotaxis trended toward being significantly decreased compared to the isogenic capsule-deficient derivative (CP9.137) (□, P = 0.10). Neutrophil chemotaxis toward live E. coli strains was both N-t-BOC sensitive and insensitive. N-t-BOC-sensitive chemotaxis was significantly decreased toward the live, wild-type E. coli strain (CP9) that possessed an O antigen compared to an isogenic O-antigen-deficient derivative (CP921) (#, P = 0.03 compared to CP9, paired t test; n = 14 for each strain). N-t-BOC-insensitive chemotaxis was significantly decreased toward the live, wild-type E. coli strain (CP9) that possessed an O antigen compared to an isogenic O-antigen-deficient derivative (CP921) (⧫, P = 0.008 compared to CP9, paired t test; n = 14 for each strain), and N-t-BOC-insensitive chemotaxis trended toward being significantly decreased compared to the isogenic capsule-deficient derivative (CP9.137) (•, P = 0.052). Neutrophil chemotaxis toward cell-free culture supernatants was primarily N-t-BOC sensitive (100, 97.4, and 96% for CP9, CP921, and CP9.137, respectively); therefore, N-t-BOC-insensitive chemotaxis toward cell-free culture supernatants is not shown. Total and N-t-BOC-sensitive chemotaxis was significantly decreased toward cell-free supernatant from the wild-type stain (CP9) that possessed a capsule compared to an isogenic capsule-deficient derivative (CP9.137) (▪, P = 0.003, paired t test; n = 5 for each supernatant).

Article Snippet: Neutrophil chemotaxis toward cell-free culture supernatants was primarily N -t-BOC sensitive (100, 97.4, and 96% for CP9, CP921, and CP9.137, respectively); therefore, N -t-BOC-insensitive chemotaxis toward cell-free culture supernatants is not shown.

Techniques: In Vitro, Chemotaxis Assay, Positive Control, Staining

Journal:

Article Title: Human Neutrophil Chemotaxis Is Modulated by Capsule and O Antigen from an Extraintestinal Pathogenic Escherichia coli Strain

doi: 10.1128/IAI.71.11.6435-6445.2003

Figure Lengend Snippet: Total in vitro chemotaxis of human neutrophils in response to cell-free culture supernatant from CP9 (wild type), CP921 (O-antigen deficient), and CP9.137 (capsule deficient) alone and in response to the mixture of supernatants from CP9 plus CP921 and CP9 plus CP9.137. Neutrophil chemotaxis was similar (not less) in response to the mixtures of supernatants from CP9 plus CP921 and CP9 plus CP9.137 compared to when the chemotactic activity due to supernatant from CP9 and CP921 alone and CP9 and CP9.137 alone was averaged (ave.) (n = 2).

Article Snippet: Neutrophil chemotaxis toward cell-free culture supernatants was primarily N -t-BOC sensitive (100, 97.4, and 96% for CP9, CP921, and CP9.137, respectively); therefore, N -t-BOC-insensitive chemotaxis toward cell-free culture supernatants is not shown.

Techniques: In Vitro, Chemotaxis Assay, Activity Assay

Journal:

Article Title: Human Neutrophil Chemotaxis Is Modulated by Capsule and O Antigen from an Extraintestinal Pathogenic Escherichia coli Strain

doi: 10.1128/IAI.71.11.6435-6445.2003

Figure Lengend Snippet: Ex vivo chemotaxis of human neutrophils in response to cell-free BAL fluid from rats infected with approximately 107 CFU of the E. coli strains CP9 (wild type), CP921 (O-antigen deficient) or CP9.137 (capsule deficient). One hour after bacterial challenge, BAL was performed and cell-free BAL fluid was used as the chemoattractant. The total deduced N-t-BOC-sensitive and the N-t-BOC-insensitive chemotaxis indices are depicted (see Materials and Methods for details on these indices). Total, N-t-BOC-sensitive, and N-t-BOC-insensitive chemotaxis was significantly decreased toward the wild-type E. coli strain that possessed a capsule compared to an isogenic capsule-deficient derivative at 1 h post-bacterial challenge. *, for total chemotaxis, P was ≤0.001 compared to CP9; #, for N-t-BOC-sensitive chemotaxis, P was 0.048 compared to CP9; &, for N-t-BOC-insensitive chemotaxis, P was <0.004 (P values are per paired t test; n = 18).

Article Snippet: Neutrophil chemotaxis toward cell-free culture supernatants was primarily N -t-BOC sensitive (100, 97.4, and 96% for CP9, CP921, and CP9.137, respectively); therefore, N -t-BOC-insensitive chemotaxis toward cell-free culture supernatants is not shown.

Techniques: Ex Vivo, Chemotaxis Assay, Infection