Effects of IL-10 and IL-4 on neutrophil-derived COX-2 mRNA expression. Human neutrophils (5 × 10⁷ cells) were cultured with or without 10 ng/mL of IL-10 or IL-4 in the presence or absence of LPS (100 ng/mL). After 5 hours, total RNA was isolated and analyzed by Northern blot using a COX-2 probe. Similar results were obtained in two separate experiments.