Immunolocalization of prostasomes in the human prostate.

Prostasomes are prostate-derived organelles, which can be isolated from seminal plasma. We have produced a panel of monoclonal antibodies against purified human prostasomes by intrasplenic immunization. Among the prostasome-positive mAbs obtained, one antibody (mAb 78) was selected for further characterization. SDS-PAGE and Western blots demonstrated that mAb 78 recognized a hand of about 35 kDa from purified prostasomes, seminal plasma and extracts of prostatic gland tissues. Immunostaining with mAb 78 resulted in positive reactions in the apical parts of the secretory cells of the prostate epithelium and in the secretions of the gland lumen. The nuclei were not stained. The mAb 78 has the potentials of a prostasome marker.