IL-6 precludes the differentiation induced by IL-3 on expansion of CD34+ cells from cord blood

• Published in: Haematologica (Roma) 2003-04, Vol.88 (4), p.388
• Main Authors: Encabo, A, Mateu, E, Carbonell-Uberos, F, Minana, MD
• Format: Article
• Language: English
• Subjects: Antigens, CD34; Cell Culture Techniques - methods; Cell Differentiation - drug effects; Cell Division - drug effects; Cytokines - pharmacology; Drug Antagonism; Fetal Blood - cytology; Humans; Interleukin-3 - pharmacology; Interleukin-6 - pharmacology; Telomerase - metabolism
• ISSN: 0390-6078; 1592-8721

Instituto de Biologia Celular, Organismo Publico Valenciano de Investigacion, Valencia, Spain. BACKGROUND AND OBJECTIVES: Ex vivo expansion of hematopoietic progenitor cells (HPC) from umbilical cord blood (UCB) is an interesting strategy to obtain a sufficient number of transplantable cells for adults. To define the optimal culture conditions allowing the generation of HPC that retain their proliferative capacity without loss of long-term culture-initiating cells (LTC-IC), the effect of different cytokine combinations on the expansion of CD34+ cells from UCB was assessed. DESIGN AND METHODS: CD34+ cells were cultured in serum-free culture medium with four cytokine combinations: stem cell factor plus thrombopoietin plus flk2/flt3 ligand (STF), STF plus interleukin-3 (IL-3), STF plus interleukin-6 (IL-6) and STF plus IL-6 plus IL-3. After a 1-week culture, the number of CD34+ and CD133+ cells, colony forming units (CFU), LTC-IC and telomerase activity were determined. RESULTS: The addition of IL-6 or IL-3 to the combination of STF significantly enhanced the expansion of CD34+, CD133+ cells and CFU. All cytokine combinations tested induced a slight increase in LTC-IC number except that composed by STF plus IL-3. The greatest induction of telomerase activity was observed with the combination of STF plus IL-3 or plus IL-3 plus IL-6. Decay of the activity along time was observed when the combination of STF plus IL-3 was used, and this effect was reverted by the addition of IL-6. INTERPRETATION AND CONCLUSIONS: Our results demonstrate that the inclusion of IL-6 in a serum-free short-term culture has a beneficial effect on HPC expansion from UCB, and precludes the negative effects induced by IL-3 on LTC-IC expansion and telomerase activity.