WT or PARP-1−/− mice were subjected to OVA sensitization followed by a single or triple challenge (Multiple) or left unchallenged. WT mice were administered i.p. 1 mg/kg, 5 or 10 mg/kg of olaparib or saline 30 min after each challenge. Mice were sacrificed 48 h later and lungs were subjected to BAL. Assessment of BALF from the different groups for Th2 cytokines eotaxin, IL-4, IL-5, IL-6, IL-13, or M-CSF (a), IL-2 (b) or INF-γ (c). Data are means ± SD of values from at least six mice per group. Asterisk difference from control unchallenged mice, p < 0.01; hash difference from OVA-challenged mice; p < 0.01.