Fig. 4.

Nasal IL-4 activates splenic dendritic cells (DC). DC were enriched from PBS- (□) and IL-4 (500 ng/rat) (▪)-treated rats on day 14 p.i., and their lipopolysaccharide (LPS) responses were evaluated by measuring (a) ³H-thymidine incorporation; (b) nitric oxide (NO) production; (c) IFN-γ-secreting DC; (d) intracellular IL-10⁺ DC, both spontaneously and upon stimulation with LPS (10 μg/ml). Data are representative of two independent experiments with similar results. *P < 0.05; **P < 0.01; ***P < 0.001.