A histiocyte is a vertebrate cell that is part of the mononuclear phagocyte system (also known as the reticuloendothelial system or lymphoreticular system). The mononuclear phagocytic system is part of the organism's immune system. The histiocyte is a tissuemacrophage[1] or a dendritic cell[2] (histio, diminutive of histo, meaning tissue, and cyte, meaning cell). Part of their job is to clear out neutrophils once they've reached the end of their lifespan.
Histiocytes are derived from the bone marrow by multiplication from a stem cell. The derived cells migrate from the bone marrow to the blood as monocytes. They circulate through the body and enter various organs, where they undergo differentiation into histiocytes, which are part of the mononuclear phagocytic system (MPS).
However, the term histiocyte has been used for multiple purposes in the past, and some cells called "histocytes" do not appear to derive from monocytic-macrophage lines.[3] The term Histiocyte can also simply refer to a cell from monocyte origin outside the blood system, such as in a tissue (as in rheumatoid arthritis as palisading histiocytes surrounding fibrinoid necrosis of rheumatoid nodules).
These histiocytes are part of the immune system by way of two distinct functions: phagocytosis and antigen presentation. Phagocytosis is the main process of macrophages and antigen presentation the main property of dendritic cells (so called because of their star-like cytoplasmic processes).
Macrophages and dendritic cells are derived from common bone marrow precursor cells that have undergone different differentiation (as histiocytes) under the influence of various environmental (tissue location) and growth factors such as GM-CSF, TNF and IL-4. The various categories of histiocytes are distinguishable by their morphology, phenotype, and size.
Macrophages are highly variable in size and morphology, their cytoplasm contains numerous acid phosphatase laden lysosomes – in relation to their specialised phagocytic function. They express CD68.
Dendritic cells have an indented (bean-shaped) nucleus and cytoplasm with thin processes (dendritic). Their main activity is antigen presentation; they express Factor XIIIa, CD1c, and Class II Human leukocyte antigens.
Langerhans cells
A subset of cells differentiates into Langerhans cells; this maturation occurs in the squamous epithelium, lymph nodes, spleen, and bronchiolar epithelium. Langerhans cells are antigen-presenting cells but have undergone further differentiation. Skin Langerhans cells express CD1a, as do cortical thymocytes (cells of the cortex of the thymus gland). They also express S-100, and their cytoplasm contains tennis-racket like ultra-structural inclusions called Birbeck granules.
^Cline, Mj (1 November 1994). "Histiocytes and histiocytosis". Blood. 84 (9): 2840–2853. doi:10.1182/blood.V84.9.2840.2840.
^Chorro L, Geissmann F (December 2010). "Development and homeostasis of 'resident' myeloid cells: the case of the Langerhans cell". Trends in Immunology. 31 (12): 438–45. doi:10.1016/j.it.2010.09.003. PMID 21030305.
^Webb DK (October 1996). "Histiocyte disorders". British Medical Bulletin. 52 (4): 818–25. doi:10.1093/oxfordjournals.bmb.a011585. PMID 9039734.
May 19, 2023
histiocyte, histiocyte, vertebrate, cell, that, part, mononuclear, phagocyte, system, also, known, reticuloendothelial, system, lymphoreticular, system, mononuclear, phagocytic, system, part, organism, immune, system, histiocyte, tissue, macrophage, dendritic,. A histiocyte is a vertebrate cell that is part of the mononuclear phagocyte system also known as the reticuloendothelial system or lymphoreticular system The mononuclear phagocytic system is part of the organism s immune system The histiocyte is a tissue macrophage 1 or a dendritic cell 2 histio diminutive of histo meaning tissue and cyte meaning cell Part of their job is to clear out neutrophils once they ve reached the end of their lifespan HistiocyteDetailsSystemImmune systemIdentifiersLatinmacrophagocytus immobilisMeSHD006644THH2 00 03 0 01009FMA83585Anatomical terms of microanatomy edit on Wikidata Contents 1 Development 2 Structure 2 1 Macrophages and dendritic cells 2 2 Langerhans cells 3 Clinical significance 4 See also 5 ReferencesDevelopment EditHistiocytes are derived from the bone marrow by multiplication from a stem cell The derived cells migrate from the bone marrow to the blood as monocytes They circulate through the body and enter various organs where they undergo differentiation into histiocytes which are part of the mononuclear phagocytic system MPS However the term histiocyte has been used for multiple purposes in the past and some cells called histocytes do not appear to derive from monocytic macrophage lines 3 The term Histiocyte can also simply refer to a cell from monocyte origin outside the blood system such as in a tissue as in rheumatoid arthritis as palisading histiocytes surrounding fibrinoid necrosis of rheumatoid nodules Some sources consider Langerhans cell derivatives to be histiocytes 4 The Langerhans cell histiocytosis embeds this interpretation into its name Structure EditHistiocytes have common histological and immunophenotypical characteristics demonstrated by immunostains Their cytoplasm is eosinophilic and contains variable amounts of lysosomes They bear membrane receptors for opsonins such as IgG and the fragment C3b of complement They express LCAs leucocyte common antigens CD45 CD14 CD33 and CD4 also expressed by T helper cells Macrophages and dendritic cells Edit These histiocytes are part of the immune system by way of two distinct functions phagocytosis and antigen presentation Phagocytosis is the main process of macrophages and antigen presentation the main property of dendritic cells so called because of their star like cytoplasmic processes Macrophages and dendritic cells are derived from common bone marrow precursor cells that have undergone different differentiation as histiocytes under the influence of various environmental tissue location and growth factors such as GM CSF TNF and IL 4 The various categories of histiocytes are distinguishable by their morphology phenotype and size Macrophages are highly variable in size and morphology their cytoplasm contains numerous acid phosphatase laden lysosomes in relation to their specialised phagocytic function They express CD68 Dendritic cells have an indented bean shaped nucleus and cytoplasm with thin processes dendritic Their main activity is antigen presentation they express Factor XIIIa CD1c and Class II Human leukocyte antigens Langerhans cells Edit A subset of cells differentiates into Langerhans cells this maturation occurs in the squamous epithelium lymph nodes spleen and bronchiolar epithelium Langerhans cells are antigen presenting cells but have undergone further differentiation Skin Langerhans cells express CD1a as do cortical thymocytes cells of the cortex of the thymus gland They also express S 100 and their cytoplasm contains tennis racket like ultra structural inclusions called Birbeck granules Clinical significance EditHistiocytoses describe neoplasias wherein the proliferative cell is the histiocyte The most common histiocyte disorders are Langerhans cell histiocytosis and haemophagocytic lymphohistiocytosis 5 See also EditHistiocytosisReferences Edit Cline Mj 1 November 1994 Histiocytes and histiocytosis Blood 84 9 2840 2853 doi 10 1182 blood V84 9 2840 2840 Chorro L Geissmann F December 2010 Development and homeostasis of resident myeloid cells the case of the Langerhans cell Trends in Immunology 31 12 438 45 doi 10 1016 j it 2010 09 003 PMID 21030305 S12C3 Granuloma Retrieved 2009 01 06 Cline MJ November 1994 Histiocytes and histiocytosis Blood 84 9 2840 53 doi 10 1182 blood V84 9 2840 2840 PMID 7524755 Webb DK October 1996 Histiocyte disorders British Medical Bulletin 52 4 818 25 doi 10 1093 oxfordjournals bmb a011585 PMID 9039734 Retrieved from https en wikipedia org w index php title Histiocyte amp oldid 1147974616, wikipedia, wiki, book, books, library,
