Immunosuppression by Human Seminal Plasma&amp;—Extracellular Organelles (Prostasomes) Modulate Activity of Phagocytic Cells

Skibiński, Grzegorz; Kelly, Rodney W.; Harkiss, D.; James, Keith

doi:10.1111/j.1600-0897.1992.tb00767.x

Cited by 136 publications

(96 citation statements)

References 20 publications

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“…56,57 This activity accounts for a significant proportion of the immunosuppressive Janus-faced nature of prostasomes G Ronquist and BO Nilsson activity of human seminal plasma. 58 Since the prostasomes have the ability to adhere to spermatozoa, 45,48 there is the probability that the immunosuppressive effect associated with the prostasomes can be carried up the female genital tract with the spermatozoa.…”

Section: Immunosuppressive Activitymentioning

confidence: 99%

“…58 A direct effect of prostasomes on macrophage function is also apparent. 56 Prostasomes bind rapidly to the leucocyte cell membrane followed by internalization of the adsorbed material. Interaction of prostasomes with neutrophils and monocytes inhibits their ability to phagocytose latex particles.…”

Section: Immunosuppressive Activitymentioning

confidence: 99%

“…Interaction of prostasomes with neutrophils and monocytes inhibits their ability to phagocytose latex particles. 56 Similarly, endocytosis of prostasomes by the cells may suppress their ability to generate oxygen radicals. 56 Hence, phagocytosing cells will ingest prostasomes and consequently will become more or less inactivated.…”

Section: Immunosuppressive Activitymentioning

confidence: 99%

“…56 Similarly, endocytosis of prostasomes by the cells may suppress their ability to generate oxygen radicals. 56 Hence, phagocytosing cells will ingest prostasomes and consequently will become more or less inactivated. This would promote the survival of spermatozoa in the female genital tract.…”

Section: Immunosuppressive Activitymentioning

confidence: 99%

“…62 It has been shown that prostasomes can interact with neutrophils and reduce their capacity to produce superoxide anion after stimulation. 56 Hence, it was apparent that prostasomes could play a role as an antioxidant factor. This theme was further elaborated by Saez et al 62 These authors noticed that prostasomes had the ability to reduce ROS production by sperm preparations containing polymorphonuclear neutrophils.…”

Section: Antioxidant Capacitymentioning

confidence: 99%

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The Janus-faced nature of prostasomes: their pluripotency favours the normal reproductive process and malignant prostate growth

Ronquist

Nilsson

2004

Prostate Cancer Prostatic Dis

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Prostasomes are submicron secretory granules synthesized, stored and secreted by the epithelial cells of the human prostate gland. They are membrane-surrounded also in their extracellular appearance and the membrane architecture is composite. They are believed to be life-giving and act as protectors of the spermatozoa in the lower and upper female genital tract on their way to the ovum. Hence, the prostasomes are immunosuppressive and inhibitory of complement activation. Further, they promote sperm's forward motility and have antioxidant and antibacterial capacities. The prostasomes with their many composite abilities seem to turn against the host cell after the age of 50 y being conducive to the transition of the normal prostate epithelial cell into a neoplastic cell and therewith lay the foundations of the very high prevalence of prostate cancer of men of more than 50 y of age. Prostate Cancer and Prostatic Diseases (2004) 7, 21-31. doi:10.1038/sj.pcan.4500684 Keywords: prostasomes Prostate cancerProstate cancer is the most common cancer in men in Europe, North America, and some parts of Africa. Incidence of prostate cancer is increasing steadily in most countries. Incidence and death rates differ according to race and geographical location. 1 Different autopsy studies performed in Western and Oriental populations have shown that the prevalence of prostate cancer is significantly higher than its incidence. Comparative assessments of these studies have provided similar prevalence rates in different races and geographical areas. 2 The differences in the incidence of prostate cancer in different races and geographical areas and the different progression of this incidence in populations of a race living in a foreign geographical area, strengthen the hypothesis that genetic and lifestyle factors are responsible for the difference in post-induction progression of prostate cancer. 3,4 The incidence rate of clinically apparent prostate cancer is eight-fold higher in the United States than in Japan, while the prevalence of latent prostate cancer, a presumed precursor of clinical prostate cancer, is similar in the two countries. 5 However, the initiating and promoting factors that determine the variability in the natural history of prostate cancer remain unknown. 6 There is a substantial discrepancy between the high incidence of prostate cancer and the extremely low incidence of primary cancer in the seminal vesicles, 7 although the two glands represent neighbouring anatomical locations, both of them being exocrine accessory genital glands and both being under similar hormonal control. Hence, there may be endogenous as well as exogenous factors promotive of prostate cancer development. We hypothesize that prostasomes with their exclusive origin in the prostate gland and with their Received

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Section: Immunosuppressive Activitymentioning

confidence: 99%

Section: Immunosuppressive Activitymentioning

confidence: 99%

Section: Immunosuppressive Activitymentioning

confidence: 99%

Section: Immunosuppressive Activitymentioning

confidence: 99%

Section: Antioxidant Capacitymentioning

confidence: 99%

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The Janus-faced nature of prostasomes: their pluripotency favours the normal reproductive process and malignant prostate growth

Ronquist

Nilsson

2004

Prostate Cancer Prostatic Dis

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Prostasomes are neuroendocrine-like vesicles in human semen

et al. 1996

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BACKGROUND Prostasomes are prostate‐derived organelles that exist extracellularly in human seminal plasma. METHODS In this study, we have investigated and characterized human prostasomes with regard to their contents of synaptophysin, members of the chromogranin family, and some neuropeptides. RESULTS By radioimmunoassay measurement and electron microscopy we show the presence of the neuroendocrine markers chromogranin B, neuropeptide Y, and vasoactive intestinal polypeptide in about equimolar amount in human prostasomes and chromogranin A in about 2% of that amount. To our knowledge, such a high ratio of chromogranin B to chromogranin A has never before been observed. The membrane‐bound protein synaptophysin, a well‐established immunocytochemical marker for neuroendocrine cells and neurones, was also detected. Hence, we show that synaptophysin could be used as a marker for intact prestasomes. CONCLUSIONS The presence of synaptophysin has recently been shown in the serotonin‐containing vesicles in platelets. A protein with a similar structure denoted granulophysin has been found in granulocytes and prostasomes. It is suggested that synaptophysin and granulophysin molecules are members of a family of proteins, maybe expressed in all cells that have regulated release of granule content. Our presented data indicate a neurotransmittor function of the prostasomes. The target cells are however not known but could be either the spermatozoa, the epithelial mucous cells of the uterus or tubas or perhaps the ovum. © 1996 Wiley‐Liss, Inc.

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