Previously we showed that the ~2% of fetal liver cells reactive with an anti-CD3epsilon monoclonal antibody support ex vivo expansion of both fetal liver and bone marrow hematopoietic stem cells (HSCs); these cells express two proteins important for HSC ex vivo expansion, IGF2, and angiopoietin-like 3. Here we show that these cells do not express any CD3 protein and are not T cells; rather, we ...

Umbilical cord blood (UCB) has been used for transplantation in the treatment of hematologic disorders as a source of hematopoietic stem cells (HSCs). Because of insufficient number of cord blood CD34+ cells, the expansion of these cells seems to be important for clinical application. Mesenchymal stromal cells (MSCs), playing an important role in HSCs maintenance, were used as feeder layer. Apo...

There has been great interest in the ex vivo expansion of human long-term repopulating hematopoietic stem cells (LTR-HSCs) for a variety of clinical applications such as umbilical cord blood transplantation. The glucoprotein130 signal, activated by a complex of interleukin 6 (IL-6) and soluble IL-6 receptor (IL-6/sIL-6R), acts dramatically in synergy with the c-Kit or Flk2/Flt3 signal to expand...

BACKGROUND AND OBJECTIVE Hematopoietic stem cells are being increasingly used for treatment of malignant and nonmalignant disorders. Various attempts have been made in recent years to expand and manipulate these cells in order to increase their therapeutic potential. A Working Group on Hematopoietic Cells has analyzed the most recent advances in this field. EVIDENCE AND INFORMATION SOURCES Th...

Hox transcription factors have emerged as important regulators of primitive hematopoietic cell proliferation and differentiation. In particular, HOXB4 appears to be a strong positive regulator of hematopoietic stem cell (HSC) self-renewal. Here we demonstrate the potency of HOXB4 to enable high-level ex vivo HSC expansion. Cultures of nontransduced or GFP-transduced murine bone marrow cells exp...

In this study, we described the modelling of the expansion/maintenance of human hematopoietic stem/progenitor cells from adult human bone marrow. CD 34(+)-enriched cell populations from bone marrow were cultured in the presence and absence of human stroma in serum-free media containing bFGF, SCF, LIF and Flt-3 ligand for several days. The cells in the culture were analysed for expansion and phe...

A small number of hematopoietic stem cells (HSCs) with self-renewal and multi-lineage repopulation capacity maintain hematopoiesis during the lifetime of an individual. Moreover, HSCs and their potential exist in excess as one individual can share its HSCs with another leading to creation of a genetically identical hematopoietic system. For over half a century this property of HSCs has been uti...

The good outcome of hematopoietic stem cell (HSC) transplantation is hampered by low doses of CD34+ cell infusion. Transplanted HSCs undergo a replicative stress that causes accelerated senescence due to rapid telomere shortening. The expansion of human cord blood HSCs is instrumental in obtaining a large number of "good quality" cells, in terms of telomere length and telomerase activity compar...

Self-renewal activity is essential for the maintenance and regeneration of the hematopoietic system. The search for molecules capable of promoting self-renewal and expanding hematopoietic stem cells (HSCs) has met with limited success. Here, we show that a short isoform (AML1a) of RUNX1/AML1 has such activities. Enforced AML1a expression expanded functionally defined HSCs, with an efficiency th...

CD4+ T cells are essential for the immune response against cancer. Vaccination against cancer will likely only be effective at preventing growth of micrometastatic disease while adoptive T cell therapy will be better suited for eradication of bulky pre-existing disease (Knutson et al. Expert Opin Biol Ther 2002; 2:55-66). Problems with the use of adoptive T cell therapy include lack of CD4+ T c...