Hematopoietic stem and progenitor cells (HSPCs) can self-renew and create committed progenitors, a process supposed to involve asymmetric cell divisions (ACDs). Previously, we had linked the kinetics of CD133 expression with ACDs but failed to detect asymmetric segregation of classical CD133 epitopes on fixed, mitotic HSPCs. Now, by using a novel anti-CD133 antibody (HC7), we confirmed the occu...

Mesenchymal stem cells (MSCs) are non-hematopoietic, multipotent progenitor cells which can be isolated from various human adult tissues. In recent years, MSCs have been shown to possess broad immunoregulatory capabilities, modulating both adaptive and innate immunity. This review discusses the documented immunomodulatory capabilities of the MSCs, the possible mechanisms underlying these functi...

multiple sclerosis is an inflammatory disease of the central nervous system in which t cells experience a second phase of activation, which ultimately leads to axonal demyelination and neurological disability. the recent advances in stem cell therapies may serve as potential treatments for neurological disorders. there are broad types of stem cells such as neural, embryonic, mesenchymal and hem...

Bipotent progenitors for T and natural killer (NK) lymphocytes are thought to exist among early precursor thymocytes. The identification and functional properties of such a progenitor population remain undefined. We report the identification of a novel developmental stage during fetal thymic ontogeny that delineates a population of T/NK-committed progenitors (NK1. 1(+)/CD117(+)/CD44(+)/CD25(-))...

All blood cell lineages start from hematopoietic stem cells (HSCs), which were recently shown to represent a heterogeneous group of cells. In mice, Notch signaling promotes the maintenance of "stemness" as well as the expansion of self-renewing HSCs in vitro. Additionally, human CD34(+) cells were shown to expand in vitro in response to Notch signals. However, it is unclear whether Notch direct...

Stem cells are self-renewing cells that can differentiate into specialized cell type(s). Pluripotent stem cells, i.e. embryonic stem cells (ESC) or induced pluripotent stem cells (iPSC) differentiate into cells of all three embryonic lineages. Multipotent stem cells, like hematopoietic stem cells (HSC), can develop into multiple specialized cells in a specific tissue. Unipotent cells differenti...

A ligand for the tyrosine kinase receptor flt3/flk-2, referred to here as flt3 ligand (flt3L), was recently cloned. The effect of flt3L on purified human CD34+ progenitor cells was examined. flt3 receptor (flt3R) was detected on the surface of human bone marrow cells that were enriched for CD34 expression. The effects of flt3L and the c-kit ligand Steel factor (SLF) on hematopoietic progenitors...

The stem cell inhibitor, macrophage inflammatory proteinla (MIP-la) or LD78, protects multipotent hematopoietic progenitors in murine models from the cytotoxic effects of chemotherapy. Clinical use of human MIP-la during chemotherapy could therefore lead to faster hematologic recovery and may allow dose intensification. We have also shown that human MIP-la causes the rapid mobilization of hemat...

Intracellular Smad proteins mediate signal transduction of the transforming growth factor-beta (TGF-beta) superfamily that play pleiotropic roles in hematopoietic development, suggesting that intracellular Smad proteins may play key roles in hematopoietic regulation. Although inhibitory Smad7, which negatively regulates TGF-beta signaling, has been implicated in the development of mature hemato...

cord blood hematopoietic stem cells are widely used as an alternative source for hematopoietic stem cells transplant. increasing rate of patients who need hematopoietic stem cells transplant and many advantages of cord blood in comparison to bone marrow hematopoietic stem cells, have promoted banking of cord blood units. cord blood banking requires accurate steps in donor selection, cord blood ...