Isolation, culture and biological characteristics of endothelial progenitor cells from human umbilical cord blood CD133~+ cells / 中国组织工程研究

ABSTRACT

AIM: To study the endothelial progenitor cell markers and biological characteristics of human umbilical cord blood CD133+ cells isolated by immunomagnetic bead (IMB) method. METHODS: The experiment was carried out in the Laboratory of Burn Surgery, Xijing Hospital of the Fourth Military Medical University of Chinese PLA from November 2002 to August 2003.①CD133+ cells were enriched from human umbilical cord blood of placenta through spontaneous delivery or cesarean delivery (offered by Department of Gynecology and Obstetrics, Xijing Hospital of the Fourth Military Medical University of Chinese PLA), with the informed consents of parturients.②Human umbilical cord blood was anticoagulated by ACD-B and then diluted, 7 mL of cord blood combined with 3 mL lymphocyte isolation liquid were centrifuged for 30 minutes at 2 100 r/min. Low-density mononuclear cells coloring buffy were selected to wash off platelet and inoculated for 30 minutes by the IMB and FITC-CD133 antigen at room temperature to wash excessive antigens. The FITC-CD 133-coated IMB was added into mononuclear cells which were cultured for 30 minutes at room temperature and placed in magnetic field for 1 minute to remove the cell suspension. IMB-cell isolation liquid was supplemented to release CD133+ endothelial progenitor cells, which were cultured with EGM-2MV media in dishes coated with collagen I. And 24 hours later those unadherent cells were detached, culture liquid was removed half after 3 hours, and total culture duration was 3-4 weeks.③The morphologic change of CD133+ cells isolated with IMB were observed; The percentage of CD133+ cells in cord blood monocytes and sorting efficiency of IMB were analyzed by fluorescence activated cell sorting (FACS). The cells cultured in vitro were identified by fluorescence immunoassay and enzymo-histochemistry while transmission electron microscope (TEM) was used to observe the W-P body of mature vascular endothelial cells. RESULTS: ①Morphologic observation of CD133+ cells culture in vitro The adherent cells expanded pseudopods on days 4 and 5, and grew rapidly in clonal manner 7 days later. The cells showed a typical spindle-shaped morphology during 2-3 weeks and cluster areas of cobblestone-like cells after 2-week culture and confluence.②Isolation rate of CD133+ cells The percentage of CD133+ cells in cord blood monocytes was 0.91%. And after IMB sorting, the percentage of CD133+ cells was 85.52%.③On the fifth day, few cells were positive for CD133 while most cells were positive for CD 34 and vWF; On the tenth day, all cells were negative for CD133 and most cells were still positive for CD 34 and vWF.④The cells after 10-day culture had typical W-P body in TEM. CONCLUSION: Immunomagnetic sorting can efficiently select enriched CD133+ endothelial progenitor cells from human umbilical cord blood. Our data of CD133, CD34, vWF antibodies and TEM support the hypothesis that endothelial progenitor cells may contribute to mature vascular endothelial cells.