MONOCLONAL-ANTIBODIES TO HUMAN EPIDERMAL FILAGGRIN, SOME NOT RECOGNIZING PROFILAGGRIN

To improve understanding of human profilaggrin processing to filaggrin , we produced seven monoclonal antibodies against epidermal filaggrin (AHF1-7), They were characterized on human epidermis by indirect immun ofluorescence, immunogold labeling, and immunoblotting and found to be directed against seven different epitopes of (pro)filaggrin. AHF1-5 l abeled the keratohyalin granules and the fibrous matrix of the lower c orneocytes, and recognized filaggrin and profilaggrin. AHF6 also label ed the keratohyalin granules and the corneocyte matrix, but only recog nized filaggrin. In addition to this reactivity within the upper epide rmis, AHF4-6 stained the cytoplasm of the basal cells, and cross-react ivity of AHF5 and AHF6 with cytokeratin K14 was revealed on immunoblot s, It is interesting that AHF7 recognized filaggrin, but not profilagg rin, and labeled only the corneocyte matrix and not the keratohyalin g ranules. This indicates that filaggrin and cytokeratins share several antigenic determinants and that filaggrin bears at least one epitope a bsent from its precursor, The original series of monoclonal antibodies described here appears to be a powerful tool for studying human profi laggrin processing in normal conditions and in the keratinization diso rders in which processing is altered.