MONOCLONAL-ANTIBODY MARKER FOR OLFACTORY SUSTENTACULAR CELL MICROVILLI

Background: The olfactory epithelial sustentacular cells may support t he survival and function of olfactory receptor neurons, but few reagen ts are available to mark and manipulate such cells, Methods: Novel nas al cell-specific monoclonal antibodies were generated using whole cult ured rat olfactory mucosal cells as the antigenic stimuli, They were c haracterized by immunostaining at the light level in rat tissues and n ewborn rat olfactory cell cultures, and at the electron microscopic le vel in adult tissues using freeze-substitution, post-embedding stainin g, Results: An IgM kappa monoclonal antibody designated 1F4 selectivel y labeled apical surfaces of the rat olfactory and respiratory epithel ia in tissue sections and what appeared to be sustentacular cells in o lfactory cell cultures, Using electron microscopy, 1F4 bound selective ly to the microvilli of sustentacular cells and ductal cells of Bowman 's glands in the olfactory epithelium, and to the microvilli and cilia of ciliated but not secretory cells in the respiratory epithelium, No staining was detected in olfactory receptor neurons, basal cells, or two types of microvilli-bearing cells that differed from sustentacular cells. A contrasting antibody, 2H4, bound to granules of secretory re spiratory cells, Developmental expression of 1F4 binding began at E17 and increased at and after E18/E19, Bulbectomy did not alter 1F4 immun oreactivity, Cell culture studies found that the 1F4 epitope was exter nal and insensitive to trypsin treatment, and that both 1F4 and 2H4 po sitive cells required contact with aggregated cells for survival up to fifteen days in vitro, Conclusions: The antibody 1F4 is a useful mark er and potential manipulation reagent specific for sustentacular cells and their microvilli. (C) 1997 Wiley-Liss, Inc.