Selective immunostaining of Mehlis' gland of Opisthorchis viverrini by antibody against rat diacylglycerol kinase.

The Mehlis' gland of Opisthorchis viverrini was selectively and intensely immunopositive with an antibody against rat diacylglycerol kinase gamma, and its entire structure with associated radiating processes was clearly demonstrated by immuno-light microscopy. In immuno-electron microscopy, the immunopositive processes were revealed to contain many vesicles and vacuoles and the immunoreactive materials were deposited diffusely in the cytoplasm except for the vesicular interior. The present findings suggest that diacylglycerol kinase is present and plays roles in PKC (protein kinase C)-related signaling in the Mehlis' gland of O. viverrini. This further suggests the possibility of a new way to protect from the infection of O. viverrini in humans by using diacylglycerol kinase as a therapeutic target.