TABLE 3.
Modulation of FcR-mediated phagocytosis by PLA2 metabolites and arachidonate pathway inhibitors
Raw264.7 cells without or with a 15-min preincubation with different compounds, as indicated, were incubated in the presence of IgG-opsonized latex beads for 30 min at 37 °C, and both the particle binding (FcR binding; before trypan blue addition) and uptake (FcR phagocytosis; after trypan blue addition) were quantified by FACS analysis. Data are means ± S.E. of at least four independent experiments. 5-LOX, 5-lipoxygenase; PGE, prostaglandin E; TxB2, thromboxane B2; LT, leukotrienes.
| Condition | FcR binding (% binding) | FcR phagocytosis (% phagocytosis) |
|---|---|---|
| Control | 27.1 ± 1.1 | 20.1 ± 0.5 |
| 10 μm (30 μm) lyso-PtdIns | 25.3 ± 1.5 (25.3 ± 2.1) | 19.1 ± 0.8 (18.8 ± 1.1) |
| 300 μm GroPIns | 25.5 ± 2.5 | 16.6 ± 1.1 |
| 50 μm GroPIns4P | 26.8 ± 1.7 | 14.8 ± 0.4a |
| 50 μm GroPIns4,5P2 | 25.9 ± 1.2 | 13.5 ± 0.3a |
| 0.1 μm (1 μm) arachidonic acid | 30.4 ± 1.0 (27.9 ± 0.6) | 23.6 ± 1.0 (20.2 ± 0.8) |
| 300 μm lysine salt of acetylsalicylic acid (COX1/2 inhibitor) | 27.5 ± 1.5 | 19.0 ± 1.9 |
| 10 μm ketoconazole (thromboxane synthase and 5-LOX inhibitor) | 29.0 ± 1.7 | 21.5 ± 1.4 |
| 5 μm LY83583 (leukotriene synthesis inhibitor) | 29.1 ± 3.8 | 23.9 ± 2.4 |
| 10 μm NS5398 (COX2 inhibitor) | 29.5 ± 2.4 | 21.0 ± 4.1 |
| 10 μm REV5901 (antagonist of LTD4 receptors) | 28.5 ± 3.1 | 21.2 ± 1.1 |
| 100 nm PGE1 | 27.6 ± 2.1 | 21.9 ± 1.7 |
| 100 nm PGE2 | 29.6 ± 2.5 | 20.2 ± 2.0 |
| 100 nm TxB2 | 25.7 ± 1.0 | 17.9 ± 1.0 |
| 100 nm LTB4 | 28.4 ± 1.2 | 21.0 ± 1.7 |
| 100 nm LTC4 | 28.4 ± 0.6 | 19.6 ± 0.6 |
| 100 nm LTD4 | 27.1 ± 3.1 | 21.0 ± 2.0 |
| 100 nm LTE4 | 27.9 ± 4.3 | 21.1 ± 3.2 |
a p < 0.02 (Student's t-test), with respect to their relevant controls.