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BioMed Research International
Volume 2013 (2013), Article ID 154919, 10 pages
Research Article

Effect of Ex Vivo Culture Conditions on Immunosuppression by Human Mesenchymal Stem Cells

1Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University College of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, Republic of Korea
2Biomedical Research Institute, LIFELIVER. Co., LTD., 877-3 Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do 448-807, Republic of Korea
3Department of Pediatrics, Dong-A Medical Center, Dong-A University College of Medicine, 26 Daesingongwonro, Soe-gu, Busan 602-172, Republic of Korea

Received 7 January 2013; Revised 20 March 2013; Accepted 16 April 2013

Academic Editor: Wolfgang Arthur Schulz

Copyright © 2013 Myoung Woo Lee et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A microarray analysis was performed to investigate whether ex vivo culture conditions affect the characteristics of MSCs. Gene expression profiles were mainly influenced by the level of cell confluence rather than initial seeding density. The analysis showed that 276 genes were upregulated and 230 genes downregulated in MSCs harvested at 90% versus 50% confluence ( , ). The genes that were highly expressed in MSCs largely corresponded to chemotaxis, inflammation, and immune responses, indicating direct or indirect involvement in immunomodulatory functions. Specifically, PTGES and ULBP1 were up-regulated in MSCs harvested at high density. Treatment of MSCs with PTGES or ULBP1 siRNA reversed their inhibition of T-cell proliferation in vitro. The culture conditions such as cell confluence at harvest seem to be important for gene expression profile of MSCs; therefore, the results of this study may provide useful guidelines for the harvest of MSCs that can appropriately suppress the immune response.