BACKGROUND Airways progenitors may be involved in embryogenesis and lung repair. The characterization of these important populations may enable development of new therapeutics to treat acute or chronic lung disease. In this study, we aimed to establish the presence of bronchioloalveolar progenitors in ovine lungs and to characterize their potential to differentiate into specialized cells. RES...

BACKGROUND Adult human peripheral blood CD34-positive (CD34+) cells appear to transform into cardiomyocytes in the injured hearts of severe combined immunodeficient mice. It remains unclear, however, whether the apparent transformation is the result of transdifferentiation of the donor stem cells or of fusion of the donor cell with the cardiomyocyte of the recipients. METHODS AND RESULTS We p...

Immunotherapy based on natural killer (NK) cell infusions is a potential adjuvant treatment for many cancers. Such therapeutic application in humans requires large numbers of functional NK cells that have been selected and expanded using clinical grade protocols. We established an extremely efficient cytokine-based culture system for ex vivo expansion of NK cells from hematopoietic stem and pro...

Definition of the cytokine environment, which regulates the maturation of human natural killer (NK) cells, has been largely based on in vitro assays because of the lack of suitable animal models. Here we describe conditions leading to the development of human NK cells in NOD/SCID mice receiving grafts of hematopoietic CD34+ precursor cells from cord blood. After 1-week-long in vivo treatment wi...

Abstract Immunodeficient NCG mice were unable to reconsituted human NK cells, but after knockin of IL-15 (hIL-15), the NCG-hIL15 could assist reconstitution cells. Compared with NCG, level hIL-15 was significantly increased in heterozygous and homozygous mice. After transplanting PBMC (huPBMC-NCG-hIL15) or cells into (huNK-NCG-IL15), peripheral blood hCD56+ huNK-NCG-hIL15 much higher than that ...

A major limitation to clinical stem cell-mediated gene therapy protocols is the low levels of engraftment by transduced progenitors. We report that CXCR4 overexpression on human CD34+ progenitors using a lentiviral gene transfer technique helped navigate these cells to the murine bone marrow and spleen in response to stromal-derived factor 1 (SDF-1) signaling. Cells overexpressing CXCR4 exhibit...

RATIONALE several studies demonstrate that hematopoietic tissues are a source of endothelial progenitor cells, which contribute to newly formed blood vessels during tissue repair in adults. However, it is not clear which cell type in these hematopoietic tissues gives rise to endothelial progenitor cells. OBJECTIVE to identity the origin of endothelial progenitors within the hematopoietic hier...

Human natural killer (NK) cells originate from CD34(+) hematopoietic progenitor cells, but the discrete stages of NK cell differentiation in vivo have not been elucidated. We identify and functionally characterize, from human lymph nodes and tonsils, four NK cell developmental intermediates spanning the continuum of differentiation from a CD34(+) NK cell progenitor to a functionally mature NK c...

Hematopoietic stem cells (HSCs) possess both self-renewal and multi-lineage differentiation abilities and maintain lifelong hematopoiesis. Recent studies have revealed that the murine HSC compartment consists of heterogeneous HSC subpopulations in terms of their lineage-biased differentiation potentials. Dykstra et al. have recently categorized murine HSCs as α-, β-, γand δ-cells, according to ...

Purified primitive progenitor/stem cells from bone marrow represent likely target populations for ex vivo expansion of stem cells to be used in high-dose chemotherapy or gene therapy. Whereas such primitive progenitor cells require combined stimulation by multiple cytokines for growth, some cytokines selectively promote viability rather than growth when acting individually. We investigated here...