CHARACTERIZATION OF LHTRIC-1, A NEW MONOSPECIFIC MONOCLONAL-ANTIBODY TO THE TRICHOCYTE KERATIN HA1

The hair follicle is a heterogeneous tissue involving differentiation of both hair forming (trichocyte) and non-hair forming (root sheath) c ells; while there are many antibody markers available which can determ ine the distribution of 'soft' epithelial keratins, fewer have been de scribed which are truly monospecific for hair specific 'hard' keratins . We employed the proven strategy of raising monoclonal antibodies to a short synthetic peptide from the carboxy-terminal sequence of mouse Ha1 and report here the successful production of a monospecific monocl onal antibody which we have called LHTric-1. We have characterized the antibody using immunostaining on rat and human tissues and by immunob lotting against an extract of human follicles. The antibody cross-reac ted between rat and human tissue but did not stain formalin-fixed tiss ue. LHTric-1 localized very specifically to the pre-cortical region of the hair follicle in early anagen and to pre-cortical cells in the up per bulb in anagen, Telogen follicles did not react. LHTric-1 immunore acted within tongue and nail, staining being restricted to the mid-lin e above the connective tissue core in tongue and to the suprabasal lay ers of the nail matrix. The antibody did not react with the fully kera tinized hair or nail plate. Finally, in immunoblotting, LRTric-1 react ed with a single band of 44 kDa, suggesting that a single protein was recognized, We conclude that this antibody, by virtue of its known ant igen sequence specificity, will be useful in research into the formati on of hair and nail in normal and diseased states.