Hematopoiesis leading to a diversity of dendritic antigen-presenting cell types

Sawang Petvises1, Helen C O'Neill

  • 1Division of Biomedical Sciences, Stem Cell and Immunology Lab, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia.

Hematopoietic stem cells (HSCs) undergo expansion and differentiation, giving rise to all terminally differentiated blood cells throughout life. HSCs are found in distinct anatomical sites during development, and in adults, hematopoiesis occurs predominantly on the luminal side of the bone cavity in bone marrow. Millions of newly formed blood cells are generated per second to accommodate the short half-life of hematopoietic cells. For this to happen, HSCs must sustain their self-renewal capacity as well as their capability to commit and differentiate toward multiple cell lineages. Development of the hematopoietic system is finely regulated as the animal ages, so that it does not become exhausted or misdirected. This review covers aspects of hematopoietic development from the embryonic period through adult life in relation to development of dendritic cells. It also considers a role for HSCs in extramedullary sites and their possible role in myelopoiesis, with formation of tissue-specific antigen-presenting cells.

Related Concept Videos

Diversity of Antigen Receptors01:28

Diversity of Antigen Receptors

Antigen receptors are essential components of the immune system crucial in defending the body against foreign invaders. These receptors are present on the surface of B and T cells, enabling them to recognize antigens and mount an appropriate immune response.
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
Antigen Presenting Cells01:22

Antigen Presenting Cells

The immune system is a complex network of cells and molecules that protects the body from foreign invaders. T cells, a type of white blood cell, play a crucial role in this process. They recognize and attack foreign substances, such as pathogens, that enter the body.
T cells require the help of antigen-presenting cells (APCs), which process foreign antigens into smaller fragments that can be recognized by T cells. These APCs are highly specialized cells that efficiently internalize antigens...
Cells of the Adaptive Immune Response01:23

Cells of the Adaptive Immune Response

The T and B lymphocytes of the adaptive immune system develop from common lymphoid progenitor cells in the bone marrow. These progenitors give rise to precursors that eventually develop into both T and B lymphocytes. As these precursors mature, they gain the ability to detect and respond to foreign antigens in the body, a process known as immunocompetence. Additionally, these precursors acquire self-tolerance, a process that ensures they do not react to self-antigens. This intricate system...
Hematopoiesis01:21

Hematopoiesis

The process of blood cell formation is called hematopoiesis. Hematopoiesis starts early during development, on the seventh day of embryogenesis. This phase of hematopoiesis is called the primitive wave, wherein the extraembryonic yolk sac allows the production of erythroid cells and endothelial cells from a common precursor called hemangioblast. The erythroid cells provide oxygen to support the growth of the rapidly dividing embryo. Hemangioblasts later develop into hematopoietic stem cells or...
T Cell Activation and Clonal Selection01:22

T Cell Activation and Clonal Selection

T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...
B Cell Activation and Differentiation01:24

B Cell Activation and Differentiation

The adaptive immune response, a sophisticated defense mechanism, relies on the activation and differentiation of B lymphocytes, or B cells. These processes enable our bodies to mount a tailored response against specific pathogens such as bacteria, free virus particles, toxins, and parasites.
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...