Human brain endothelial cells (HUBEC) promote SCID repopulating cell expansion through direct contact.
The objective of this study was to re-evaluate the previously published hematopoietic stem cell (HSC) expansion work using human brain endothelial cells (HUBEC). The expansion effect of contact and non-contact conditions was reported to be equivalent by others. However, we report here different results that the expansion can be achieved only with direct contact. We co-cultured human CD34+ cells with and without HUBEC contact for seven days with cytokines and the readouts were CD34+ / CD38 - phenotype and SCID repopulating cell (SRC) frequency. Also tested was the inhibitory effect of Wnt receptor inhibitor Dkk-1 on HUBEC contact ex vivo expansion; whether an increased expression of Wnt3 occurs on the HUBEC surface; and detection of an increased nuclear localization of beta-catenin in CD34+ / CD38- cells in HUBEC contact culture condition. We conclude that the successful expansion by HUBEC contact culture is a candidate explanation based on the Wnt family protein, possibly Wnt3, expression on HUBEC.
Greenebaum Cancer Center, University of Maryland, Baltimore, MD 21201, USA.
Xiangfei
X
Cheng
Thomas
T
Macvittie
Barry
B
Meisenberg
Emily
E
Welty
Ann
A
Farese
Douglas
D
Tadaki
Naoko
N
Takebe
D051997:ADP-ribosyl Cyclase 1 / Q000378:metabolism; D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D001921:Brain / Q000098:blood supply; D002448:Cell Adhesion; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000166:cytology* / Q000502:physiology; D004730:Endothelium, Vascular / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000502:physiology; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D051379:Mice; D016513:Mice, SCID; D016511:Severe Combined Immunodeficiency / Q000276:immunology; D051153:Wnt Proteins / Q000378:metabolism; D060508:Wnt3 Protein; D051176:beta Catenin / Q000096:biosynthesis
D018952:Antigens, CD34; C501126:DKK1 protein, human; D036341:Intercellular Signaling Peptides and Proteins; C555507:WNT3 protein, human; D051153:Wnt Proteins; D060508:Wnt3 Protein; C555508:Wnt3 protein, mouse; D051176:beta Catenin; D051997:ADP-ribosyl Cyclase 1