Proteomic profiling of human embryonic stem cell-derived microvesicles reveals a risk of transfer of proteins of bovine and mouse origin.
OBJECTIVE
Microvesicles (MV) shed from the plasma membrane of eukaryotic cells, including human embryonic stem cells (hESC), contain proteins, lipids and RNA and serve as mediators of cell-to-cell communication. However, they may also contain immunogenic membrane domains and infectious particles acquired from xenogenic components of the culture milieu. Therefore, MV represent a potential risk for clinical application of cell therapy.


METHODS
We tested the ability of hESC and their most commonly used feeder cells, mouse embryonic fibroblasts (MEF), to produce MV. We found that hESC are potent producers of MV, whereas mitotically inactivated MEF do not produce any detectable MV. We therefore employed a combined proteomic approach to identify the molecules that constitute the major components of MV from hESC maintained in a standard culture setting with xenogenic feeder cells.


RESULTS
In purified MV fractions, we identified a total of 22 proteins, including five unique protein species that are known to be highly expressed in invasive cancers and participate in cellular activation, metastasis and inhibition of apoptosis. Moreover, we found that hESC-derived MV contained the immunogenic agents apolipoprotein and transferrin, a source of Neu5Gc, as well as mouse retroviral Gag protein.


CONCLUSIONS
These findings indicate that MV represent a mechanism by which hESC communicate; however, they also serve as potential carriers of immunogenic and pathogenic compounds acquired from environment. Our results highlight a potential danger regarding the use of hESC that have previously been exposed to animal proteins and cells.
Kubikova
I
I
Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic.
Konecna
H
H
Sedo
O
O
Zdrahal
Z
Z
Rehulka
P
P
Hribkova
H
H
Rehulkova
H
H
Hampl
A
A
Chmelik
J
J
Dvorak
P
P
D000818:Animals; D015478:Antigens, Heterophile / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000276:immunology / Q000378:metabolism; D001053:Apolipoproteins / Q000276:immunology / Q000378:metabolism; D051017:Apoptosis Regulatory Proteins / Q000276:immunology / Q000378:metabolism; D002417:Cattle; D002460:Cell Line; D064987:Cell- and Tissue-Based Therapy / Q000009:adverse effects; D055252:Cell-Derived Microparticles / Q000276:immunology* / Q000378:metabolism; D018920:Coculture Techniques; D053595:Embryonic Stem Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D015683:Gene Products, gag / Q000276:immunology / Q000378:metabolism; D006801:Humans; D051379:Mice; D008854:Microscopy, Electron; D040901:Proteomics; D012306:Risk; D053719:Tandem Mass Spectrometry; D014168:Transferrin / Q000276:immunology / Q000378:metabolism
D015478:Antigens, Heterophile; D000951:Antigens, Neoplasm; D001053:Apolipoproteins; D051017:Apoptosis Regulatory Proteins; D015683:Gene Products, gag; D014168:Transferrin