FIG. 1.

IL-15^−/− mice are not deficient in early IFN-γ production or susceptible to acute toxoplasmosis. C57BL/6 mice and IL-15^−/− mice were infected intraperitoneally with 20 cysts of ME49 and samples were collected 7 dpi. (A) Serum was collected from wild-type (WT) (n = 6) and knockout (KO) (n = 5) mice 7 dpi and IFN-γ was measured by enzyme-linked immunosorbent assay. Data shown are representative of three individual experiments. (B) Antigen-specific IFN-γ production was measured by stimulating splenocytes from mice infected 7 days earlier for 48 h with soluble Toxoplasma antigen (STAg). No defect in IFN-γ production was observed. Data shown are representative of three individual experiments. (C) Splenocytes were surface stained for CD3 and NK1.1 to assess the total NK⁺ CD3⁻ cell population. Data shown are representative of two individual experiments containing at least three mice per group. (D) C57BL/6 mice (n = 18) and IL-15^−/− mice (n = 15) were infected intraperitoneally with 20 cysts of ME49 and survival was monitored. Results presented are pooled data from three independent experiments containing no less than four mice per group.