A third-phase cutaneous (very late phase) response after elicitation with dinitrofluorobenzene in passively or actively sensitized mice

Abstract

Previous studies have reported that the mice passively sensitized with anti-dinitrophenol (DNP) IgE antibody exhibited IgE-mediated cutaneous reaction with an immediate phase response (IPR) at 1 h and a late phase response (LPR) at 24 h after the challenge of dinitrofluorobenzene (DNFB). We found that the third-phase inflammatory reaction with intense and persisting infiltration of eosinophils, named ‘very late phase reaction (vLPR)’, was induced following IPR and LPR in response to DNFB in actively and passively sensitized mice, and that the peak response of vLPR was at 8 days after the challenge. This reaction was slightly observed in non-sensitized mice. Since the accumulation of eosinophils in vLPR was markedly observed when compared with that of LPR at 24 h, the vLPR may be an important reaction in allergic diseases. The development of vLPR was partly decreased in mast cell-deficient WBB6F1-W/Wv mice and was absent in T cell-deficient BALB/c-nu/nu mice in passive sensitization. These results indicate that the vLPR in the triphasic cutaneous reaction may be mainly mediated by T cells and partially by mast cells and/or IgE antibody, and consequently lead to an intense ear swelling accompanying massive infiltration of eosinophils.