Fig. 4

Abs response in macaques from the Alum group throughout the immunization scheme. a Titers of anti-IL-15 Abs detected by ELISA in macaques immunized with mhIL-15 adjuvanted in Alum. The plate was coated with 1 μg/ml mhIL-15 and serum was evaluated in twofold serial dilutions (starting dilution 1:1000). The Abs titers of pre-immune animals, placebo group and the monkeys immunized with mhIL-15 in Alum after the second, third, fourth and fifth immunization are shown. The line represents the mean values of Abs titers calculated from duplicate samples of individual animals (n = 3) during the scheme. b Proliferation assay in CTLL-2 cells with the serum of one animal from the Alum group. Cells were cultured in the presence of native IL-15, IL-15 plus dilutions of the pre-immune serum, or serum from each immunization (starting dilution 1:100), IL-15 plus serial dilutions of an anti-human IL-15 Ab and cells culture in medium without cytokine. Cell proliferation was evaluated by MTT staining. Similar results were obtained when the sera of other animals from the same group were assessed. d: days after immunization; m: months after immunization