Effect of anti-CD52 antibody alemtuzumab on <it>ex-vivo </it>culture of umbilical cord blood stem cells

• Main Authors: Law Ping, Feng Qi, Sun Li, Lim Che K, Chua Wei T, Lim Shy N, Hwang William YK
• Format: Article
• Language: English
• Published: BMC 2008-10-01
• Series: Journal of Hematology & Oncology
• Online Access: http://www.jhoonline.org/content/1/1/19

<p>Abstract</p> <p>Background</p> <p>Excessive maturation of hematopoietic cells leads to a reduction of long-term proliferative capability during cord blood (CB) expansion. In this study, we report the effects of anit-CD52 (Alemtuzumab, Campath) on both short- and long-term <it>ex vivo </it>expansion of CB hematopoietic stem cells (HSC) by evaluating the potential role of Alemtuzumab in preserving the repopulating capability in CB HSC and nonlymphoid progenitors.</p> <p>Methods</p> <p><it>Ex vivo </it>expansion experiments were carried out using freshly purified CB CD34⁺cells in StemSpan™ SFEM medium in the presence of stem cell factor, Flt3-Ligand and thrombopoietin at 50 ng/ml. Alemtuzumab (10 μg/ml) was used to deplete CD52⁺cells during the cultures. Flow cytometry was used to monitor CB HSC and their differentiation. Colony forming unit (CFU) assays and long term culture-initiating cell (LTC-IC) assays were performed on cells obtained from day 0 (before culture) and day 14 after cultures. Secondary cultures was performed using CD34⁺cells isolated at 35 days from primary cultures and further cultured in StemSpan™ SFEM medium for another 14 days to confirm the long term effect of alemtuzumab in liquid cultures.</p> <p>Results</p> <p>Compared to cytokines alone, addition of alemtuzumab resulted in a significant increase in total nucleated cells, absolute CD34⁺cells, myeloid and megakaryocytic progenitors, multi-lineage and myeloid CFU and LTC-IC.</p> <p>Conclusion</p> <p>The results from current study suggested that the use of alemtuzumab for <it>ex vivo </it>expansion of CBHSC maybe advantageous. Our findings may improve current technologies for CBHSC expansion and increase the availability of CB units for transplantation. However, <it>in vivo </it>studies using animal models are likely needed in further studies to test the hematopoietic effects using such expanded CB products.</p>