KERATIN 19-LIKE IMMUNOREACTIVITY IN RECEPTOR-CELLS OF MAMMALIAN TASTE-BUDS

Three monoclonal antibodies, 4.62, LP2K and 170.2.14, were used to eva luate keratin 19-like immunoreactivity in gustatory epithelia. Keratin 19-like immunoreactivity was restricted to the intragemmal cells for all types of mammalian taste buds examined. These taste buds included fungiform, foliate and vallate taste buds in rat, gerbil and rabbit, a nd nasopalatine, epiglottal and palatine taste buds in rat. There was no keratin 19-like immunoreactivity in basal cells or in perigemmal ce lls lateral to the immunoreactive taste receptor cells. Denervation of the rat vallate papilla eliminated all taste buds, as well as all imm unoreactive taste cells. That the immunoreactive material in the taste cells was keratin 19 was supported by the comparable staining of rat taste buds with each of three monoclonal antibodies specific for kerat in 19. Furthermore, as predicted, these antibodies selectively stained luminal cells of rat bile ducts, bladder, salivary ducts, trachea, ur eter and uterus. It was concluded that monoclonal antibodies against k eratin 19 can usefully distinguish intragemmal taste receptor cells fr om keratinocytes, and from the perigemmal and basal cells of gustatory epithelia. Anti-keratin 19 antibodies may serve to identify different iated taste cells in gustatory epithelia undergoing taste bud developm ent, renewal, degeneration or regeneration.