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Flt3L induces the ex‐vivo amplification of umbilical cord blood committed progenitors and early stem cells in short‐term cultures
Author(s) -
De Felice Lidia,
Di Pucchio Tiziana,
Grazia Mascolo Maria,
Agostini Francesca,
Breccia Massimo,
Guglielmi Cesare,
Rosaria Ricciardi Maria,
Tafuri Agostino,
Screnci Maria,
Mandelli Franco,
Arcese William
Publication year - 1999
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1046/j.1365-2141.1999.01519.x
Subject(s) - stem cell , progenitor cell , cd34 , cord blood , umbilical cord , biology , multipotent stem cell , stem cell factor , ex vivo , andrology , immunology , transplantation , microbiology and biotechnology , in vitro , medicine , genetics
Umbilical cord blood (UCB) has been successfully used for haemopoietic stem cell transplantation, although its use has been cautiously limited to paediatric patients because of the reduced volume produced. The clinical results have confirmed that either engraftment or survival significantly correlate with cell dose infused. We have standardized a culture method providing in a short time a significant amplification of both committed progenitors and primitive stem cells for clinical use. Eight‐day culture of UCB cells with flt3L/SCF/PIXY 321 induced a 10‐fold amplification of CD34 + cells and the expansion of multipotent (CFU‐GEMM) and committed (CFU‐GM, BFU‐E) progenitors respectively of 5‐, 7‐ and 9‐fold over input cells. As to the early stem cell pool, the primitive CD34 + Thy‐1 + cell fraction increased 6‐fold and the LTC‐IC were amplified 17‐fold. Furthermore, the in vitro proliferation was detected by the gradual loss of fluorescence of the CD34 + cells tracked at day 0 with the dye PKH26. After 8 d of amplification >6% of the CD34 + cells remained intensely fluorescent. This subpopulation represents a deeply quiescent cell fraction unresponsive to cytokines and very enriched of primitive stem cells. These cells are most likely to be responsible for long‐term reconstitution after transplant.