Adherence of human prostasomes to mouse spermatozoa and their displacement by monoclonal antibodies as revealed by free zone electrophoresis

Prostasomes: current concepts

BACKGROUND

Prostasomes are membranous vesicles secreted by prostate gland, and they contain large amounts of cholesterol, sphingomyelin, calcium, and several enzymes. Prostasomes are involved in a number of biological functions. At ejaculation, these prostasomes are expelled with prostate secretions and are to be found in the seminal plasma as seminal prostasomes, which facilitate sperm function in various ways.

METHODS

In this review, we discuss the structural and functional role of prostasomes, the various enzyme systems associated with these vesicles, and the biological role prostasomes play in male reproduction. RESULTS AND CONCLUSIONS Prostasomes are pluripotent and well-organized organelles secreted by the prostate gland. Prostasomes are ascribed to have many physiologiocal functions, the primary function being enhancement of sperm capacity. The several enzyme systems, small signaling molecules, and neuroendocrine markers associated with prostasomes reveal the complex nature of these vesicles in regulating sperm viability and vitality. The functional significance of these molecules that regulate complex pathways in these small vesicles is still a matter of dogma. Critical evaluation of the biological processes associated with prostasomes might be helpful in modeling new contraceptive agents, improving the techniques of in vitro fertilization, and in furthering our understanding and treatment of male factor infertility.

Monoclonal antibodies against human prostasomes

BACKGROUND

The prostasomes are secreted into the gland ducts of the human prostate. At ejaculation, these native prostasomes are expelled with the secretions of the prostate and appear in the seminal plasma as seminal prostasomes, where they facilitate sperm function in various ways. We have designed methods for producing monoclonal anti-prostasome antibodies to be used for immunohistochemistry and sequencing analyses of the prostasomes.

METHODS

The immunogen applied was purified seminal prostasomes placed on small pieces of nitrocellulose membranes (prostasome blots) and deposited into the spleen of mice for immunization. For screening, both seminal and native prostasomes were used.

RESULTS

We obtained antibodies which detected native prostasomes both in prostatic secretions and in paraffin sections of the prostate. The immunostaining demonstrated that all prostate epithelial cells contained prostasomes. They were located in the apical parts of the secretory cells and in the gland ducts, while the nuclei and the corpora amylacea were unstained.

CONCLUSIONS

Using the methods described, monoclonal antibodies against native prostasomes were produced. In addition to their usefulness in structural and functional studies of prostasomes, specific monoclonal antibodies can be used to characterize prostasomes by sequencing analyses.