[In vitro expansion of cord blood megakaryocyte progenitor].
OBJECTIVE
To expand cord blood megakaryocyte progenitor cells in vitro.


METHODS
Cord blood CD34+ cells were selected by magnetic cell sorting (MACS), and thrombopoietin (TPO), interleukin-11 (IL-11), and heparin were used in the expansion system of megakaryocyte progenitor. The expansion efficiency was measured by fluorescence-activated cell sorting (FACS) using the megakaryocytic specific monoclonal antibodies (CD34+, CD41a+, CD61+, CD34+CD41a+, CD41a+CD61+) and colony-forming units-megakaryocyte (CFU-MK) analysis. The expanded megakaryocyte progenitor were determined by histochemistry staining using CD41a and the observation of the ultrastructure of megakaryocyte (MK) by electron microscopy. The megakaryocyte function were examined by the platelet activation in vitro and nonobese diabetic/severe combined immunodifficiency (NOD/SCID) mice transplantation in vivo.


RESULTS
CD34+CD41a+ cells was expanded (4.0 +/- 1.7) folds on day 7 in TPO (50 ng/ml) group and (10.5 +/- 4.8) fold in TPO combined with IL-11 group; after heparin was joined in on day 0, a more significantly elevated expansion was found in the heparin, TPO, and IL-11 group [(29.9 +/- 6.4) folds than the above two groups; P < 0.05]. Meanwhile, the large CFU-MK colony (> 50 cells/colony) was (106.8 +/- 26.9) folds on day 7 (P < 0.05). The megakaryocyte expanding with TPO, IL-11 and heparin for 7 days in vitro transplanted the NOD/SCID mice fasten the recovery of platelet and white blood cell account and improved the survival. Megakaryocyte under culture displayed certain development of territories membrane. Platelet activation test comfirmed that the expanding megakaryocyte progenitor had the normal function.


CONCLUSIONS
TPO, IL-11, and heparin combination system for ex vivo expansion is an effective expansion system of megakaryocyte progenitor.
Feng
Yi
Y
National Key Laboratory of Experimental Hematology, Institute of Hematology, CAMS and PUMC, Tianjin 300020, China.
Xiao
Zhi-jian
ZJ
Xu
Shi-cai
SC
Lu
Shi-hong
SH
Liu
Bin
B
Liu
Jin-hua
JH
Han
Zhong-chao
ZC
D000818:Animals; D018952:Antigens, CD34; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D005312:Fetal Blood / Q000166:cytology*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D017370:Interleukin-11 / Q000494:pharmacology; D008297:Male; D008533:Megakaryocytes / Q000166:cytology* / Q000276:immunology; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D013926:Thrombopoietin / Q000494:pharmacology
D018952:Antigens, CD34; D017370:Interleukin-11; D006493:Heparin; D013926:Thrombopoietin