Human hemopoietic stem cells (HSC) have been shown to engraft, differentiate, and proliferate in the hemopoietic tissues of sublethally irradiated NOD/LtSZ scid/scid (NOD/SCID) mice. We used this model to study homing, survival, and expansion of human HSC populations from different sources or phenotype. We observed that CD34+ cells homed specifically to bone marrow (BM) and spleen, but by 3 day...

Growth factor receptors in human hematopoietic progenitor cells have become the focus of intense interest, because they may provide tools for the monitoring, enrichment, and expansion of stem cells. We have shown earlier that the Tie receptor tyrosine kinase is expressed in erythroid and megakaryoblastic human leukemia cell lines, in the blood islands of the yolk sac, and in endothelial cells s...

From September 1992 to January 1994, we evaluated the use of the CEPRATE SC stem cell concentrator (CellPro, Inc, Bothell, WA) to select CD34+ cells from the bone marrow (BM) of 25 patients with non-Hodgkin's lymphoma in complete remission. This system uses the biotinylated 12.8 IgM MoAb to select CD34+ cells. Cells are retained on an avidin column and detached by agitation. Fifteen patients ha...

In skin, IL-9 is best known as a key cytokine in contact dermatitis. Yet, we noted that its receptor (IL-9R) was also expressed the hair follicle (HF) epithelium. Therefore, asked whether IL-9R-mediated signaling modulated human HF growth and/or immune status. To address this, full-length healthy scalp HFs were organ-cultured presence/absence of recombinant (rh) for six days. Quantitative (immu...

We have developed a stromal-based in vitro culture system that facilitates ex vivo expansion of transplantable CD34(+) thy-1(+) cells using long-term hematopoietic reconstitution in severe combined immunodeficient-human (SCID-hu) mice as an in vivo assay for transplantable human hematopoietic stem cells (HSCs). The addition of leukemia inhibitory factor (LIF) to purified CD34(+) thy-1(+) cells ...

Background TSLP has been described as a “master TH2 cytokine” with pleiotropic effects. Recent research shows that TSLP can directly activate mast cells and CB CD34 hemopoietic progenitor cells (HPC), with release of TH2 cytokines/chemokines in a TSLP-dependent manner [1,2]. Additionally, TSLP may modulate the function of CD34 cells via changes in hemopoietic cytokine receptors (HCR), which are...

Acute myeloid leukemia (AML) occurs as the result of malignant transformation in a hematopoietic progenitor cell, which proliferates to form an accumulation of AML blasts. Only a minority of these AML cells are capable of proliferation in vitro, suggesting that AML cells may be organized in a hierarchy, with only the most primitive of these cells capable of maintaining the leukemic clone. To fu...

Previous studies have suggested a "catalytic role" in neoplastic angiogenesis and cancer progression for bone marrow-derived endothelial progenitor cells (EPC). However, preclinical and clinical studies have shown that the quantitative role of marrow-derived EPCs in cancer vascularization is extremely variable. We have found that human and murine white adipose tissue (WAT) is a very rich reserv...

Peripheral blood (PB) CD34+ cells mobilized by granulocyte colony-stimulating factor (G-CSF) administration are potentially useful for transplantation and as a target of gene transfer for therapy of hematopoietic disorders. Efficient harvest and planning for clinical use of PB CD34+ cells ideally requires foreknowledge of the expected mobilization kinetics and yield. We developed a sensitive fl...