Palladium Attenuates the Pro-Inflammatory Interactions of C5a, Interleukin-8 and Pneumolysin with Human Neutrophils

Figures & data

TABLE 1 Effects of pre-treatment with Co^{2 +}, Pd^{2 +}, Pt^{4 +}, V^{2 +}, V^{3 +}, V^{4 +}, V^{5 +} (all at 25 μ M) on the Ca^{2 +}-mobilizing interactions of C5a, IL-8, and pneumolysin with neutrophils

System	Peak neutrophil Cytosolic Ca^2 + value (nM)
C5a only (control)	577 ± 24
C5a + Co^2 +	564 ± 9
C5a + Pd^2 +	129 ± 8
C5a + Pt^4 +	565 ± 15
C5a + V^2 +	554 ± 17
C5a + V^3 +	566 ± 6
C5a + V^4 +	587 ± 9
C5a + V^5	554 ± 20
IL-8 only (control)	449 ± 40
IL-8 + Co^2 +	462 ± 18
IL-8 + Pd^2 +	303 ± 23
IL-8 + Pt^4 +	464 ± 14
IL-8 + V^2 +	463 ± 12
IL-8 + V^3 +	411 ± 6
IL-8 + V^4 +	385 ± 33
IL-8 + V^5 +	386 ± 31
Pneumolysin only (control)	457 ± 31
Pneumolysin + Co^2 +	413 ± 14
Pneumolysin + Pd^2 +	127 ± 6
Pneumolysin + Pt^4 +	456 ± 18
Pneumolysin + V^2 +	439 ± 16
Pneumolysin + V^3 +	456 ± 12
Pneumolysin + V^4 +	439 ± 19
Pneumolysin + V^5 +	447 ± 19

The results of five experiments are expressed as the mean peak neutrophil cytosolic Ca^{2 +} concentrations ± SE recorded immediately after the addition of C5a or IL-8 to the cells, or at approximately 1 min after the addition of pneumolysin. Mean cytosolic Ca^{2 +} concentration for resting cells, recorded prior to the addition of the chemoattractants/pneumolysin, was 121 ± 7.1 nM. *p < 0.05.

FIG. 1 Effect of exposure to Pd^{2 +} (25 μ M) on the Ca^{2 +}-mobilizing interactions of C5a with neutrophils shown as the fura-2 fluorescence traces of 2 representative experiments (5 in the series). The responses of cells exposed to untreated, or to Pd^{2 +}-treated C5a (added as denoted by the arrow ↓) are shown on the left and right sides of each pair of traces, respectively.

FIG. 2 Effect of exposure to Pd^{2 +} (25 μ M) on the Ca^{2 +}-mobilizing interactions of IL-8 with neutrophils is shown as the fura-2 fluorescence traces of 2 representative experiments (5 in the series). The responses of the cells exposed to untreated, or to Pd^{2 +}-treated IL-8 (added as denoted by the arrow ↓) are shown on the left and right sides of each pair of traces, respectively.

FIG. 3 Effect of exposure to Pd ^{2 +} (25 μ M) on the Ca^{2 +}-mobilizing interactions of pneumolysin with neutrophils is shown as the fura-2 fluorescence traces of 2 representative experiments (5 in the series). The responses of the cells exposed to untreated, or to Pd^{2 +}-treated pneumolysin (added as denoted by the arrow ↓) are shown on the left and right sides of each pair of traces, respectively.

FIG. 4 Effect of exposure to varying concentrations of Pd^{2 +} (6.25–25 μ M) on the Ca^{2 +} -mobilizing interactions of IL-8 (added as denoted by the arrow ↓) with neutrophils are shown as the fura-2 fluorescence traces of a single representative experiment (3 in the series).

FIG. 5 Effect of exposure to various concentrations of Pd^{2 +} (6.25–25 μ M) on the Ca^{2 +} -mobilizing interactions of pneumolysin (added as denoted by the arrow ↓) with neutrophils are shown as the fura-2 fluorescence traces of a single representative experiment (3 in the series).

FIG. 6 Effect of exposure to Pd^{2 +} (25 μ M) on the chemotactic activities of C5a and IL-8 for neutrophils. The results of 3 experiments (with 6 replicates for each system) are expressed as the mean values (cells/microscope high-powered field) ± SEM. *p < 0.05.