The roles of IL-4, IL-5 and mast cells in the accumulation of eosinophils during allergic cutaneous late phase reaction in mice

Late phase allergic response has been implicated in the pathogenesis of all ergic diseases. In the current study, we investigated the role of IL-4, IL- 5 and mast cells in the development of cutaneous late phase reaction (LPR) in mice. Antigenic challenge of ears of ovalbumin (OVA)-immunized BALB/c mi ce caused a biphasic ear swelling peaking at 1 hr (immediate phase reaction : IPR) and 24 hr (LPR). Ear swelling in LPR was significantly suppressed by the treatment with anti-IL-4 monoclonal antibody (mAb) before antigen chal lenge. Local eosinophil accumulation during LPR, however, was not inhibited by anti-IL-4 mAb. Moreover, anti-IL-5 mAb had no effect on the swelling re sponse though it significantly suppressed the local accumulation of eosinop hils. Interestingly, mast cell-deficient mice (WBB6F1-W/W-v) developed LPR without exhibiting IPR, while the magnitude of ear swelling and local eosin ophilia was significantly lower than in normal congenic mice (+/+ mice), Th e present findings show that IL-4 and IL-5 differently regulate the develop ment of LPR, and that IgE-mediated mast cell activation is required for ful l response. (C) 2001 Elsevier Science Inc. All rights reserved.