Abstract
Exosomes are nanosized membrane-bound microvesicles that originate from the endosomal compartment and convey cell–cell contact ‘by proxy’, transporting signals/packages of information between donor and recipient cells locally and/or at a distance. Exosomes are produced by a variety of immune, epithelial and tumor cells. Upon contact, exosomes transfer molecules that can render new properties and/or reprogram the recipient cells. Recently, it was discovered that the syncytiotrophoblast of human placenta continuously and constitutively secretes exosomes throughout pregnancy. These exosomes, delivered directly in the maternal blood surrounding the chorionic villi of the placenta, are immunosuppressive and pluripotent carrying proteins, mRNA and miRNA that can influence a number of biologic mechanisms and promote the fetal allograft survival. The current knowledge regarding placental exosomes and their role in pregnancy is summarized and discussed in this article.
Acknowledgements
The author wishes to thank Vladimir Baranov for unique and invaluable collaboration in the field of placental exosome research.
Financial & competing interests disclosure
The generous grant support by the Swedish National Cancer Research Foundation Cancerfonden (CAN 2008/627, #08 0360), the research foundations Cancerforskningsfonden I Norrland (AMP 08-587) and Insamlingsstiftelsen Umeå University are gratefully acknowledged. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
No writing assistance was utilized in the production of this manuscript.