FIG. 1.

Enhanced O₂⁻ production by IL-15- and IL-2-treated monocytes. Human elutriated monocytes were treated for 18 h (A and B) or 48 h (C and D) with increasing concentrations of IL-15 (▨) or IL-2 ( ). Untreated control cells were simultaneously incubated in medium alone (▪). Cells treated for 48 h also were incubated with a combination of IL-2 and IL-15 at 50 ng of each per ml (▩). Superoxide anion release was measured in response to PMA (A and C) or opsonized C. albicans blastoconidia (B and D), as described in Materials and Methods. Data were collected from four to six experiments, performed in duplicate with different donors, and are expressed as means ± standard errors of the means. There was a significant enhancement in O₂⁻ release from cells treated with ≥50 ng of IL-15 per ml (∗∗, P < 0.01; ∗∗∗, P < 0.001) or ≥100 ng of IL-2 per ml (∗, P ≤ 0.05; ∗∗, P < 0.01) in response to both PMA and C. albicans blastoconidia.