Properties and histochemical application of a novel antibody against trichohyalin granules.

We obtained an antibody, anti-inner root sheath cells antibody (anti-IRSC Ab), that reacted with the inner root sheath (IRS) cells especially trichohyalin granules (THG). In order to compare the properties of anti-IRSC Ab and AE15, which is a specific monoclonal antibody against THG, histochemical and biochemical examinations were performed. In vivo localization with anti-IRSC Ab and AE15 indicated that both antibodies reacted with THG, but anti-IRSC Ab reacted with THG in the suprabulbar region of the Huxley layer, whereas AE15 reacted with THG in the suprabulbar region and upper bulbar portion of the Huxley layer, as shown by immunohistochemical and immunoelectron microscopic analyses. The results of immunoblot analysis showed that anti-IRSC Ab reacted with a protein spot at 45 kDa, pI 6.5, but AE15 reacted with high molecular weight proteins at pI 5.5. Furthermore, anti-IRSC Ab reacted with specimens of squamous cell carcinoma (SCC) but did not react with those of basal cell carcinoma (BCC). In contrast, AE15 reacted with neither SCC nor BCC. These findings suggest that anti-IRSC Ab and AE 15 recognized different component proteins in THG, and therefore indicated that THG, like as keratohyalin granules, might consist of several proteins. It is the novel finding that the anti-IRSC Ab positive substance in THG in the normal hair and SCC cells.