PMN granulocyte

(noun)

A type of phagocyte that contains PMN granules, most notably neutrophils and mast cells, but also basophiles and eosinophils.

Related Terms

Examples of PMN granulocyte in the following topics:

  • Phagocytes

    • Mature monocytes have large, smooth, lobed nuclei and an abundant cytoplasm that contains granules, but are not technically considered granulocytes.
    • Mature macrophages are derived from monocytes, granulocyte stem cells, or the cell division of pre-existing macrophages.
    • Neutrophils are a type of PMN granulocyte normally found in the bloodstream.
    • Mast cells are PMN granulocytes with toll-like receptors that tend to trigger inflammatory responses.
    • Monocytes differentiate into dendritic cells and macrophages, while mast cells and neutrophils are in a separate group of PMN granuolcytes as well.

  • Types of WBCs

    • A major distinguishing feature is the presence of granules; white blood cells are often characterized as granulocytes or agranulocytes.
    • Granulocytes, also known as polymorphonuclear (PMN) leukocytes, are characterized by stained granules within their cytoplasm under a microscope.
    • Granulocytes contain toll-like receptors that allow them to recognize pathogen-associated molecular patterns (PAMPS).
    • There are four types of granulocytes:
    • Distinguish between the two major types of leukocytes (white blood cells): granulocytes and agranulocytes

  • Immunodeficiencies

    • Granulocyte deficiency referes to decreased numbers of granulocytes (called granulocytopenia or, if absent, agranulocytosis) such as of neutrophil granulocytes (termed neutropenia).
    • Granulocyte deficiencies also include decreased function of individual granulocytes, such as in chronic granulomatous disease.
    • Asplenia is a granulocyte deficiency in which the spleen does not function.
    • There are over 80 recognised primary immunodeficiency syndromes—generally grouped by the part of the immune system that is malfunctioning, such as lymphocytes or granulocytes.

  • White Blood Cells

    • One of the two main groups are the granulocytes, which contain granules in their cytoplasm, and include the neutrophils, eosinophils, and basophils ( a).
    • (a) Granulocytes (neutrophils, eosinophils and basophils) are characterized by a lobed nucleus and granular inclusions in the cytoplasm.
    • Granulocytes are typically first-responders during injury or infection.

  • Iron-Binding Proteins

    • Lactoferrin is also present in secondary granules of PMN (Polymorphonucler neutrophil) and is secreted by some acinar cells.

  • Immune Complex Autoimmune Reactions

    • Activation of complement primarily results in cleavage of soluble complement proteins forming C5a and C3a, which activate recruitment of PMNs and local mast cell degranulation (requiring the binding of the immune complex onto FcγRIII), resulting in an inflammatory response.

  • Opportunistic Microorganisms

    • It takes advantage of the opportunity to infect the lymphocytes, macrophages and granulocytes as soon as it enters the area of broken skin.

  • Growth Factors

    • An example is granulocyte macrophage colony-stimulating factor (GM-CSF), a growth factor that stimulates the production of white blood cells.

  • Development of Blood

    • Myelocytes, which include granulocytes, megakaryocytes, and macrophages, are derived from common myeloid progenitors and are involved in such diverse roles as innate immunity, adaptive immunity, and blood clotting.
    • Red and white blood cell production is regulated with great precision in healthy humans, and the production of granulocytes is rapidly increased during infection.

  • Primary Immunodeficiency Diseases

    • The basic tests performed when an immunodeficiency is suspected should include a full blood count ( including accurate lymphocyte and granulocyte counts) and immunoglobulin levels.
    • Monocytes/macrophages as well as granulocytes are capable of this process.