Leukocytes

Examples of Leukocytes in the following topics:

• WBC Function

  • Many leukocytes are able to perform their functions in tissues or organs, sometimes due to damage or inflammation, and sometimes due to normal leukocyte transport through those organs.
  • Leukocyte functions may be classified as either innate or adaptive immune system, based on several characteristics.
  • Innate immune system functions from leukocytes include:
  • This process is performed primarily by neutrophils, macrophages, and dendritic cells, but most other leukocytes can do it as well.
  • Adaptive immune functions of leukocytes include:

• WBC Formation

  • The daughters of HSCs are the myeloid and lymphoid progenitor cells, which cannot self-renew themselves, but differentiate into various myeloid leukocytes and lymphocytes respectively.
  • There are two different lineages of leukocytes that arise from the progeny of HSCs, as well as two other lineages of non-leukocytes.
  • Following this split in differentiation, the different subtypes undergo eventual differentiation into terminally differentiated leukocytes, which do typically do not divide anymore on their own.
  • Megakaryocytes (the cells that produce platelets) and Erythrocytes (red blood cells) are not formally considered to be leukocytes, but arise from the common myeloid progenitor cells that produce the other cellular components of blood.

• Types of WBCs

  • The different types of white blood cells (leukocytes) include neutrophils, basophils, eosinophils, lymphocytes, monocytes, and macrophages.
  • White blood cells, or leukocytes, are cells of the immune system involved in defending the body against both infectious disease and foreign materials.
  • Granulocytes, also known as polymorphonuclear (PMN) leukocytes are leukocytes characterized by differently stained granules within their cytoplasm under light microscopy.
  • Mononuclear (MN) leukocytes, are leukocytes characterized by having a single round, nucleus within the cytoplasm.
  • Distinguish between the two major types of leukocytes (white blood cells): granulocytes and agranulocytes

• Pathogen Recognition

  • A neutrophil is also a phagocytic leukocyte that engulfs and digests pathogens .
  • An eosinophil is a leukocyte that works with other eosinophils to surround a parasite.
  • A basophil is a leukocyte that, like a neutrophil, releases chemicals to stimulate the inflammatory response .
  • Eosinophils and basophils produce additional inflammatory mediators to recruit more leukocytes.
  • Leukocytes (1, 2, 3) are white blood cells that play an important role in the body's immune system.

• MHC Polymorphism and Antigen Binding

  • MHC molecules display a molecular fraction called an epitope and mediate interactions of leukocytes with other leukocytes or body cells.
  • MHC molecules display a molecular fraction called an epitope and mediate interactions of leukocytes with other leukocytes or body cells.
  • Human MHC class I and II are also called human leukocyte antigen (HLA).
  • The human leukocyte antigen (HLA) system is the name of the major histocompatibility complex (MHC) in humans.

• Connective Tissues: Bone, Adipose, and Blood

  • The living cell types are red blood cells, also called erythrocytes, and white blood cells, also called leukocytes .
  • Leukocytes are white blood cells of the immune system involved in defending the body against both infectious disease and foreign materials.
  • Leukocytes are found throughout the body, including the blood and lymphatic system.
  • Two additional leukocytes in the blood are eosinophils and basophils, both of which help to facilitate the inflammatory response.
  • Also present are various leukocytes (white blood cells) involved in immune response.

• Major Histocompatibility Complex Antigens (Self-Antigens)

  • MHC molecules mediate interactions of leukocytes, with other leukocytes or body cells.
  • In humans, MHC is also called human leukocyte antigen (HLA), because MHC can often act as an antigen for human leukocytes.
  • MHC is also called human leukocyte antigen (HLA), and varies considerably among different members of the same species.

• Components of Blood

  • The cellular components of blood are erythrocytes (red blood cells, RBCs), leukocytes (white blood cells), and thrombocytes (platelets).
  • Leukocytes (also called white blood cells or WBCs) are usually larger in size (10-14 micrometers in diameter) than red blood cells and they lack hemoglobin but do contain organelles, a nucleus, and nuclear DNA.

• White Blood Cells

  • White blood cells, also called leukocytes, play an important role in the body's immune response by identifying and targeting pathogens.
  • White blood cells, also called leukocytes (leuko = white), make up approximately one percent, by volume, of the cells in blood.

• Types of Cytokines Participating in Immune Response

  • Interleukins are a class of cytokines that are primarily expressed by leukocytes.
  • Leukocytes travel along chemotactic gradients that guide them to site of injury, infection, or inflammation.By definition, inflammatory mediators in other classes of cytokines are also considered to be chemokines, but this category also includes cytokines that are only involved in leukocyte migration, such as CCL2, which causes monocyte chemotaxis and stimulates its differentiation into macrophages inside of tissues.