Prostasomes are extracellular vesicles (40-500 nm in diameter) secreted by the prostate gland epithelial cells into seminal fluid.
Prostasomes appear to improve sperm motility and protect against attacks from the female immune defense during the passage to the egg.
[2] The name prostasomes was coined in the early 1980s by combining the terms "prosta"=prostate and "soma" (Greek for "body").
[9] Prostasomes have also been implicated in the interaction between prostatic cancer cells and their microenvironment.
[10] Immune regulating proteins found in prostasomes include: amino-peptidase N (CD13); dipeptidyl-peptidase IV (CD26); enkephalinase (neutral endopeptidase, CD10); angiotensin converting enzyme (ACE, CD143); tissue factor TF (CD142, thromboplastin); decay accelerating factor (CD55); protectin (CD59, inhibitor of MAC) and complement regulatory membrane cofactor protein (CD46).