Basophil granulocytes Granulocytes are a category of white blood cells characterised by the presence of granules in their cytoplasm. They are also called polymorphonuclear leukocytes because of the varying shapes of the nucleus, which is usually lobed into three segments. In common parlance, the term polymorphonuclear leukocyte often refers specifically to neutrophil, sometimes referred to as basophils, are the least common of the granulocytes Granulocytes are a category of white blood cells characterised by the presence of granules in their cytoplasm. They are also called polymorphonuclear leukocytes because of the varying shapes of the nucleus, which is usually lobed into three segments. In common parlance, the term polymorphonuclear leukocyte often refers specifically to neutrophil, representing about 0.01% to 0.3% of circulating white blood cells White blood cells , or leukocytes (also spelled "leucocytes"), are cells of the immune system defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a hematopoietic stem cell.
The name comes from the fact that these leucocytes are basophilic, i.e., they are susceptible to staining In biochemistry it involves adding a class-specific dye to a substrate to qualify or quantify the presence of a specific compound. It is similar to fluorescent tagging by base In chemistry, a base is most commonly thought of as an aqueous substance that can accept hydrogen ions. Bases are also the oxides or hydroxides of metals. A soluble base is also often referred to as an alkali if hydroxide ions are involved. This refers to the Brønsted-Lowry theory of acids and bases. Alternative definitions of bases include dyes A dye can generally be described as a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and may require a mordant to improve the fastness of the dye on the fiber, as shown in the picture.
Basophils contain large cytoplasmic The cytoplasm is the part of a cell that is enclosed within the cell membrane. In eukaryotic cells, the contents of the cell nucleus are not part of the cytoplasm and are instead called the nucleoplasm. Also in eukaryotic cells, the cytoplasm contains organelles, such as mitochondria, which are filled with liquid that is kept separate from the granules which obscure the cell nucleus In cell biology, the nucleus , also sometimes referred to as the "control center", is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes under the microscope A microscope is an instrument to see objects too tiny for the naked eye. The science of investigating small objects using such an instrument is called microscopy. Microscopic means invisible to the eye unless aided by a microscope. However, when unstained, the nucleus is visible and it usually has 2 lobes. The mast cell A mast cell is a resident cell of several types of tissues and contains many granules rich in histamine and heparin. Although best known for their role in allergy and anaphylaxis, mast cells play an important protective role as well, being intimately involved in wound healing and defense against pathogens, a cell The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular . Other organisms, such as humans, are multicellular. (Humans have an estimated 100 trillion in tissues Tissue is a cellular organizational level intermediate between cells and a complete organism. Hence, a tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues, has many similar characteristics. For example, both cell types store histamine Histamine is a biogenic amine involved in local immune responses as well as regulating physiological function in the gut and acting as a neurotransmitter. Histamine triggers the inflammatory response. As part of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in nearby connective tissues, a chemical that is secreted by the cells when stimulated in certain ways (histamine causes some of the symptoms of an allergic Allergy is a disorder of the immune system often also referred to as atopy. Allergic reactions occur to normally harmless environmental substances known as allergens; these reactions are acquired, predictable, and rapid. Strictly, allergy is one of four forms of hypersensitivity and is called type I hypersensitivity. It is characterized by reaction). Like all circulating granulocytes, basophils can be recruited out of the blood Blood is a specialized bodily fluid that delivers necessary substances to the body's cells — such as nutrients and oxygen — and transports waste products away from those same cells into a tissue when needed.
Contents |
Function
Reference ranges for blood tests A reference range is a set of values used by a health professional to interpret a set of medical test results. The range is usually defined as the set of values 95 percent of the normal population falls within , or two standard deviations from the mean, although the definition may differ (see Definition of reference range). It is determined by of white blood cells, comparing basophil granulocyte amount (shown in violet) with other cells.Basophils appear in many specific kinds of inflammatory Inflammation is the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli as well as initiate the healing process for the tissue. Inflammation is not a synonym for infection. Even in cases where reactions, particularly those that cause allergic symptoms. Basophils contain anticoagulant heparin Heparin, a highly-sulfated glycosaminoglycan, is widely used as an injectable anticoagulant, and has the highest negative charge density of any known biological molecule. It can also be used to form an inner anticoagulant surface on various experimental and medical devices such as test tubes and renal dialysis machines. Pharmaceutical grade, which prevents blood from clotting too quickly. They also contain the vasodilator histamine, which promotes blood flow to tissues. They can be found in unusually high numbers at sites of ectoparasite infection, e.g., ticks Tick is the common name for the small arachnids in superfamily Ixodoidea that, along with other mites, constitute the Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and occasionally reptiles and amphibians. Ticks are vectors of a number of diseases, including Lyme disease, Q fever, Colorado tick fever,. Like eosinophils Eosinophil granulocytes, usually called eosinophils , are white blood cells that are one of the immune system components responsible for combating infection and parasites in vertebrates. Along with mast cells, they also control mechanisms associated with allergy and asthma. They are granulocytes that develop during Haematopoiesis in the bone, basophils play a role in both parasitic infections and allergies[1]. They are found in tissues where allergic reactions are occurring and probably contribute to the severity of these reactions. Basophils have protein receptors on their cell surface that bind IgE Antibodies are gamma globulin proteins that are found in blood or other bodily fluids of vertebrates, and are used by the immune system to identify and neutralize foreign objects, such as bacteria and viruses. They are typically made of basic structural units—each with two large heavy chains and two small light chains—to form, for example,, an immunoglobulin involved in macroparasite defense and allergy Allergy is a disorder of the immune system often also referred to as atopy. Allergic reactions occur to normally harmless environmental substances known as allergens; these reactions are acquired, predictable, and rapid. Strictly, allergy is one of four forms of hypersensitivity and is called type I hypersensitivity. It is characterized by. It is the bound IgE antibody that confers a selective response of these cells to environmental substances, for example, pollen Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement between the stamens to the pistil of flowering plants or from the male cone to the female cone of coniferous plants. When pollen lands proteins Proteins are organic compounds made of amino acids arranged in a linear chain and folded into a globular form. The amino acids in a polymer chain are joined together by the peptide bonds between the carboxyl and amino groups of adjacent amino acid residues. The sequence of amino acids in a protein is defined by the sequence of a gene, which is or helminth Parasitic worms or helminths are a division of eukaryotic parasites that, unlike external parasites such as lice and fleas, live inside their host. They are worm-like organisms that live and feed off living hosts, receiving nourishment and protection while disrupting their hosts' nutrient absorption, causing weakness and disease. Those that live antigens. Recent studies in mice suggest that basophils may also regulate the behavior of T cells T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They can be distinguished from other lymphocyte types, such as B cells and natural killer cells by the presence of a special receptor on their cell surface called T cell receptors . The abbreviation T, in T cell, and mediate the magnitude of the secondary immune response.
Secretions
When activated, basophils degranulate Degranulation is a cellular process that releases antimicrobial cytotoxic molecules from secretory vesicles called granules found inside some cells. It is used by several different cells involved in the immune system, including granulocytes and Mast cells, and certain lymphocytes such as natural killer (NK) cells and cytotoxic T cells, whose main to release histamine Histamine is a biogenic amine involved in local immune responses as well as regulating physiological function in the gut and acting as a neurotransmitter. Histamine triggers the inflammatory response. As part of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in nearby connective tissues, proteoglycans Proteoglycans are glycoproteins that are heavily glycosylated. They have a core protein with one or more covalently attached glycosaminoglycan chain(s). The chains are long, linear carbohydrate polymers that are negatively charged under physiological conditions, due to the occurrence of sulfate and uronic acid groups. Proteoglycans occur in the (e.g. heparin Heparin, a highly-sulfated glycosaminoglycan, is widely used as an injectable anticoagulant, and has the highest negative charge density of any known biological molecule. It can also be used to form an inner anticoagulant surface on various experimental and medical devices such as test tubes and renal dialysis machines. Pharmaceutical grade and chondroitin), and proteolytic enzymes A protease breaks down proteins. A protease is any enzyme that conducts proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein. Proteases work best in acidic conditions (e.g. elastase In molecular biology, elastase is an enzyme from the class of proteases , that break down proteins and lysophospholipase Thus, the two substrates of this enzyme are 2-lysophosphatidylcholine and H2O, whereas its two products are glycerophosphocholine and carboxylate). They also secrete lipid Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, phospholipids, and others. The main biological functions of lipids include energy storage, as structural components of cell membranes, and as important signaling molecules mediators like leukotrienes Leukotrienes are fatty molecules of the immune system that contribute to inflammation in asthma and bronchitis. Leukotriene antagonists are used to treat asthma and bronchitis, and several cytokines Cytokines are any of a number of substances that are secreted by specific cells of the immune system which carry signals locally between cells, and thus have an effect on other cells. They are a category of signaling molecules that are used extensively in cellular communication. They are proteins, peptides, or glycoproteins. The term cytokine. Histamine and proteoglycans are pre-stored in the cell's granules while the other secreted substances are newly generated. Each of these substances contributes to inflammation. Recent evidence suggests that basophils are an important source of the cytokine, interleukin-4 Interleukin-4, abbreviated IL-4, is a cytokine that induces differentiation of naive helper T cells to Th2 cells. Upon activation by IL-4, Th2 cells subsequently produce additional IL-4. The cell that initially produces IL-4, thus inducing Th0 differentiation, has not been identified, but recent studies (2009) suggest that basophils may be the, perhaps more important than T cells 'T cells' belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They can be distinguished from other lymphocyte types, such as B cells and natural killer cells by the presence of a special receptor on their cell surface called T cell receptors . The abbreviation T, in T cell, stands for. Interleukin-4 is considered one of the critical cytokines in the development of allergies and the production of IgE In biology, Immunoglobulin E is a class of antibody (or immunoglobulin "isotype") that has only been found in mammals. It plays an important role in allergy, and is especially associated with type 1 hypersensitivity. IgE has also been implicated in immune system responses to most parasitic worms like Schistosoma mansoni, Trichinella antibody by the immune system. There are other substances that can activate basophils to secrete which suggests that these cells have other roles in inflammation.[2]
Basopenia Basopenia is a form of agranulocytosis associated with a deficiency of basophils (a low basophil count) is difficult to demonstrate as the normal basophil count is so low; it has been reported in association with autoimmune urticaria Urticaria (from the Latin urtica, nettle urere, to burn) (or hives) are a kind of skin rash notable for dark red, raised, itchy bumps. Hives are frequently caused by allergic reactions; however, there are many non-allergic causes. For example, most cases of hives lasting less than six weeks (acute urticaria) are the result of an allergic trigger[3] (a chronic itching condition). Basophilia is also uncommon but may be seen in some forms of leukaemia Leukemia (Greek leukos λευκός, "white"; aima αίμα, "blood") is a cancer of the blood or bone marrow and is characterized by an abnormal proliferation (production by multiplication) of blood cells, usually white blood cells (leukocytes). Leukemia is a broad term covering a spectrum of diseases. In turn, it is part of or lymphoma Lymphoma is a cancer that begins in the lymphocytes of the immune system and presents as a solid tumor of lymphoid cells. They often originate like balls in lymph nodes, presenting as an enlargement of the node . Lymphomas are closely related to lymphoid leukemias, which also originate in lymphocytes but typically involve only circulating blood.
References
- ^ Voehringer D. 2009. Trends in Parasitology.
- ^ Janeway CA, Jr. Charles Alderson Janeway, Jr. was a noted immunologist. A member of the National Academy of Sciences, he held a faculty position at Yale University's medical school and was an HHMI Investigator. He was also the son of the pediatrician Charles Alderson Janeway et al. (2001) (electronic full text via NCBI Bookshelf). Immunobiology. (5th ed. ed.). Garland Publishing. ISBN The International Standard Book Number is a unique numeric commercial book identifier based upon the 9-digit Standard Book Numbering (SBN) code created by Gordon Foster, now Emeritus Professor of Statistics at Trinity College, Dublin, for the booksellers and stationers W.H. Smith and others in 1966 0-8153-3642-X. http://www.ncbi.nlm.nih.gov/books/bv.fcgi?call=bv.View..ShowTOC&rid=imm.TOC&depth=10.
- ^ Grattan CE, Dawn G, Gibbs S, Francis DM (Mar 2003). "Blood basophil numbers in chronic ordinary urticaria and healthy controls: diurnal variation, influence of loratadine and prednisolone and relationship to disease activity". Clin Exp Allergy 33 (3): 337–41. PMID A PMID is a unique number assigned to each PubMed citation of life sciences and biomedical scientific journal articles. The related Pubmed Central archive may additionally assign a separate number, a PMCID (PubMed Central Identifier), normally written with a PMC prefix 12614448. http://www.blackwell-synergy.com/openurl?genre=article&sid=nlm:pubmed&issn=0954-7894&date=2003&volume=33&issue=3&spage=337.
Additional images
|
Blood cell lineage |
Alternate stain of a basophil |
|
||||||||||||||||||||||||||||||||||
Categories: Cell biology | Granulocytes | Human cells
<<Table of Contents | Show All>>
|
