Immunophenotype of hematopoietic stem cells from placental/umbilical cord blood after culture
Braz. j. med. biol. res
; 38(12): 1775-1789, Dec. 2005.
Article
em En
| LILACS
| ID: lil-417200
Biblioteca responsável:
BR1.1
ABSTRACT
Identification and enumeration of human hematopoietic stem cells remain problematic, since in vitro and in vivo stem cell assays have different outcomes. We determined if the altered expression of adhesion molecules during stem cell expansion could be a reason for the discrepancy. CD34+CD38- and CD34+CD38+ cells from umbilical cord blood were analyzed before and after culture with thrombopoietin (TPO), FLT-3 ligand (FL) and kit ligand (KL; or stem cell factor) in different combinations TPO + FL + KL, TPO + FL and TPO, at concentrations of 50 ng/mL each. Cells were immunophenotyped by four-color fluorescence using antibodies against CD11c, CD31, CD49e, CD61, CD62L, CD117, and HLA-DR. Low-density cord blood contained 1.4 ± 0.9 percent CD34+ cells, 2.6 ± 2.1 percent of which were CD38-negative. CD34+ cells were isolated using immuno-magnetic beads and cultured for up to 7 days. The TPO + FL + KL combination presented the best condition for maintenance of stem cells. The total cell number increased 4.3 ± 1.8-fold, but the number of viable CD34+ cells decreased by 46 ± 25 percent. On the other hand, the fraction of CD34+CD38- cells became 52.0 ± 29 percent of all CD34+ cells. The absolute number of CD34+CD38- cells was expanded on average 15 ± 12-fold when CD34+ cells were cultured with TPO + FL + KL for 7 days. The expression of CD62L, HLA-DR and CD117 was modulated after culture, particularly with TPO + FL + KL, explaining differences between the adhesion and engraftment of primary and cultured candidate stem cells. We conclude that culture of CD34+ cells with TPO + FL + KL results in a significant increase in the number of candidate stem cells with the CD34+CD38- phenotype.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
Células-Tronco Hematopoéticas
/
Imunofenotipagem
/
Sangue Fetal
Tipo de estudo:
Prognostic_studies
Limite:
Humans
/
Newborn
Idioma:
En
Revista:
Braz. j. med. biol. res
Assunto da revista:
BIOLOGIA
/
MEDICINA
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Brasil
/
Estados Unidos
País de publicação:
Brasil