hematopoietic stem cells

(noun)

Multipotent stem cells that give rise to all the blood cell types from the myeloid (monocytes and macrophages, neutrophils, basophils, eosinophils, erythrocytes, megakaryocytes/platelets, and dendritic cells), and lymphoid lineages (T-cells, B-cells, and NK-cells).

Related Terms

Examples of hematopoietic stem cells in the following topics:

  • Development of Blood

    • Hematopoietic stem cells reside in the bone marrow and have the unique ability to differentiate into all mature blood cell types.
    • Hematopoietic stem cells (HSCs) reside in the bone marrow and have the unique ability to give rise to all of the different mature blood cell types.
    • For the stem cells and other undifferentiated blood cells in the bone marrow, blood cells are determined to specific cell types at random.
    • Colony-stimulating factors (CSFs) are secreted glycoproteins that bind to receptor proteins on the surfaces of hematopoietic stem cells, thereby activating intracellular signaling pathways that can cause the cells to proliferate and differentiate into a specific kind of blood cell.
    • A comprehensive diagram showing the development of different blood cells from hematopoietic stem cell to mature cells.

  • Development of Blood and Blood Vessels

    • Endothelial stem cells (ESCs) are one of three types of stem cells found in bone marrow.
    • They give rise to endothelial progenitor cells (EPCs), intermediate stem cells that lose potency.
    • Progenitor stem cells are committed to differentiating along a particular cell developmental pathway.
    • The lineages arising from the EPC and the hematopoietic progenitor cell (HPC) form the blood circulatory system.
    • Hematopoietic stem cells can undergo self-renewal and give rise to erythrocytes (red blood cells), megakaryocytes/platelets, mast cells, T-lymphocytes, B-lymphocytes, dendritic cells, natural killer cells, monocyte/macrophage, and granulocytes.

  • Medical Uses of Hematopoietic Growth Factors

    • Hemopoetic growth factors regulate the growth, differentiation, and proliferation of progenitor cells in the blood and bone marrow.
    • Hemopoietic growth factors regulate the differentiation and proliferation of particular progenitor cells.
    • Erythropoietin is a sialoglycoprotein hormone produced by peritubular cells of kidney.
    • G-CSF stimulates the production of white blood cells (WBC).
    • G-CSF is also used to increase the number of hematopoietic stem cells in the blood of the donor before collection by leukapheresis for use in hematopoietic stem cell transplantation.

  • Maturation of T Cells

    • T cells originate from hematopoietic stem cells in the bone marrow and undergo positive and negative selection in the thymus to mature.
    • They are distinguished from other lymphocytes, such as B cells and natural killer cells (NK cells), by the presence of a T cell receptor (TCR) on the cell surface.
    • All T cells originate from hematopoietic stem cells in the bone marrow, which are capable of differentiating into any type of white blood cell.
    • A T cell is then signaled by the thymus to become a CD4+ cell by reducing expression of its CD8 cell surface receptors.
    • The remaining cells exit the thymus as mature naive T cells.

  • Mechanics of Cellular Differentation

    • An oligopotent stem cell is limited to becoming one of a few different cell types.
    • Stem cells are unique in that they can also continually divide and regenerate new stem cells instead of further specializing.
    • There are different stem cells present at different stages of a human's life, including the embryonic stem cells of the embryo, fetal stem cells of the fetus, and adult stem cells in the adult.
    • Adult bone marrow has three distinct types of stem cells: hematopoietic stem cells, which give rise to red blood cells, white blood cells, and platelets ; endothelial stem cells, which give rise to the endothelial cell types that line blood and lymph vessels; and mesenchymal stem cells, which give rise to the different types of muscle cells.
    • The multipotent hematopoietic stem cells give rise to many different cell types, including the cells of the immune system and red blood cells.

  • Cellular Differentiation

    • Three basic categories of cells make up the mammalian body: germ cells, somatic cells, and stem cells.
    • Examples of stem and progenitor cells include:
    • Hematopoietic stem cells (adult stem cells) from the bone marrow that give rise to red blood cells, white blood cells, and platelets
    • Mesenchymal stem cells (adult stem cells) from the bone marrow that give rise to stromal cells, fat cells, and types of bone cells;
    • Epithelial stem cells (progenitor cells) that give rise to the various types of skin cells

  • Clonal Selection and Tolerance

    • Central tolerance is the mechanism by which newly developing T cells and B cells are rendered non-reactive to self.
    • Peripheral tolerance is generated after the cells reach the periphery.
    • Regulatory T cells can be considered both central tolerance and peripheral tolerance mechanisms, as they can be generated from self (or foreign)-reactive T cells in the thymus during T cell differentiation.
    • Both developing B cells and T cells are subject to negative selection during a short period after antigen receptors are expressed.
    • Hematopoietic stem cell 2.

  • Clonal Selection and T-Cell Differentiation

    • The increased binding affinity may be why memory cells can eliminate a pathogen more rapidly than the original generation of effector cells.
    • Cloned daughter cells differentiate into either effector T cells or memory T cells.
    • Cytotoxic effector T cells are finished, but helper T cells continue to differentiate into individual subsets of helper T cells.
    • A hematopoietic stem cell undergoes differentiation and genetic rearrangement to produce lymphocytes in the immune system.
    • Clonal selection of lymphocytes: 1) A hematopoietic stem cell undergoes differentiation and genetic rearrangement to produce 2) immature lymphocytes with many different antigen receptors.

  • Cells and Organs of the Immune System

    • The thymus "educates" T cells and provides an inductive environment for the development of T cells from hematopoietic progenitor cells.
    • The red bone marrow is a key element of the lymphatic system, being one of the primary lymphoid organs that generate lymphocytes from immature hematopoietic progenitor cells.
    • Five different types of leukocytes exist, all produced and derived from a multipotent cell in the bone marrow known as a hematopoietic stem cell.
    • Natural killer cells are leukocytes that attack and destroy tumor cells, or cells that have been infected by viruses.
    • B cells and T cells are the major types of lymphocytes and are derived from hematopoietic stem cells in the bone marrow.

  • Gene Expression in Stem Cells

    • Symmetric division maintains stem cell lines and asymmetric division yields differentiated cells.
    • Stem cells are undifferentiated biological cells found in multicellular organisms, that can differentiate into specialized cells (asymmetric division) or can divide to produce more stem cells (symmetric division).
    • In mammals, there are two broad types of stem cells: embryonic stem cells, which are isolated from the inner cell mass of blastocysts, and adult stem cells, which are found in various tissues.
    • Notably, stem cells divide asymmetrically to give rise to two distinct daughter cells: one copy of the original stem cell as well as a second daughter programmed to differentiate into a non-stem cell fate.
    • This diagram illustrates stem cell division and differentiation, through the processes of (1) symmetric stem cell division, (2) asymmetric stem cell division, (3) progenitor division, and (4) terminal differentiation.