Specialised Macrophages having special roles in different organs are introduced as below;
- Mesangial cells:
- Mesangial cells are specialised macrophages in the kidney that play a role in restricting macromolecules from accumulating in the mesangial space by receptor- independent uptake processes of phagocytosis, micro- and macro-pinocytosis, or receptor-dependent processes.
- Alveolar macrophage or Dust cells:
- Alveolar macrophage or Dust cells are specialized macrophages of lung found in the pulmonary alveolus aqueous liquid water with dissolved gases mucus, near the pneumocytes, but separated from the wall. They are phagocytes that play a critical role in homeostasis, host defense, the response to foreign substances, and tissue remodeling.
- Microglial cells:
- Microglial cells are specialized macrophages of brain and also found in spinalcord. Microglial cells fulfill a variety of different tasks within the CNS mainly related to both immune response and maintaining homeostasis. if the microglial cell finds any foreign material, damaged cells, apoptotic cells, neurofibrillary tangles, DNA fragments, or plaques it will activate and phagocytose the material or cell.
- Langerhans cells:
- Langerhans cells are specialized macrophages of skin present in all layers of the epidermis and are most prominent in the stratum spinosum. They are active in the capture, uptake and processing of antigens.
- Histiocytes are specialized macrophages of tissue that is part of the mononuclear phagocyte system (Reticuloendothelial system). These histiocytes are part of the immune system by way of two distinct functions: phagocytosis and antigen presentation.
- Kupffer cells:
- Kupffer cells are specialized macrophages of liver which are located in the liver, lining the walls of the sinusoids. Apart from clearing any bacteria, red blood cells are also broken down by phagocytic action, where the hemoglobin molecule is split. The globin chains are re-utilized, while the iron-containing portion, heme, is further broken down into iron, which is re-utilized, and bilirubin, which is conjugated to glucuronic acid within hepatocytes and secreted into the bile.
- Follicular DCs:
- Follicular dendritic cells (FDCs) are specialized macrophages of lymphnodes and cells of the immune system found in primary and secondary lymph follicles of the B cell areas of the lymphoid tissue. FDCs enhances engulfment of apoptotic cells.
- Microfold cells (or M cells) are specialized macrophages of intestine found in the gut-associated lymphoid tissue (GALT) of the Peyer’s patches in the small intestine, and in the mucosa-associated lymphoid tissue (MALT) of other parts of the gastrointestinal tract. They selective endocytosis of antigens, and transporting them to intraepithelial macrophages and lymphocytes, which then migrate to lymph nodes where an immune response can be initiated.
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