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Intravascular Immunity
Intravascular immunity describes the immune response in the bloodstream, and its role is to fight and prevent the spread of pathogens. Components of intravascular immunity include the cellular immune response and the macromolecules secreted by these cells. It can result in responses such as inflammation and immunothrombosis. Dysregulated intravascular immune response or pathogen evasion can create conditions like thrombosis, sepsis, or disseminated intravascular coagulation.{{Cite journal, last=Jenne, first=Craig N., last2=Kubes, first2=Paul, date=2015-05-19, title=Platelets in inflammation and infection, journal=Platelets, volume=26, issue=4, pages=286–292, doi=10.3109/09537104.2015.1010441, pmid=25806786, issn=0953-7104 Cellular Defenses In a healthy individual, immune cells patrol blood vessels to detect and respond to danger through molecules frequently found on pathogens called PAMPs, and molecules that are released by damaged cells, DAMPs. Immune cells involved in intravasc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pathogen
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term ''pathogen'' came into use in the 1880s. Typically, the term ''pathogen'' is used to describe an ''infectious'' microorganism or agent, such as a virus, bacterium, protozoan, prion, viroid, or fungus. Small animals, such as helminths and insects, can also cause or transmit disease. However, these animals are usually referred to as parasites rather than pathogens. The scientific study of microscopic organisms, including microscopic pathogenic organisms, is called microbiology, while parasitology refers to the scientific study of parasites and the organisms that host them. There are several pathways through which pathogens can invade a host. The principal pathways have different episodic time frames, but soil has the longest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD36
CD36 (cluster of differentiation 36), also known as platelet glycoprotein 4, fatty acid translocase (FAT), scavenger receptor class B member 3 (SCARB3), and glycoproteins 88 (GP88), IIIb (GPIIIB), or IV (GPIV) is a protein that in humans is encoded by the CD36 gene. The CD36 antigen is an integral membrane protein found on the surface of many cell types in vertebrate animals. It imports fatty acids inside cells and is a member of the class B scavenger receptor family of cell surface proteins. CD36 binds many ligands including collagen, thrombospondin, erythrocytes parasitized with ''Plasmodium falciparum'', oxidized low density lipoprotein, native lipoproteins, oxidized phospholipids, and long-chain fatty acids. Work in genetically modified rodents suggest a role for CD36 in fatty acid metabolism,heart disease, taste, and dietary fat processing in the intestine. It may be involved in glucose intolerance, atherosclerosis, arterial hypertension, diabetes, cardiomyopathy, Alzheime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coagulation
Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechanism of coagulation involves activation, adhesion and aggregation of platelets, as well as deposition and maturation of fibrin. Coagulation begins almost instantly after an injury to the endothelium lining a blood vessel. Exposure of blood to the subendothelial space initiates two processes: changes in platelets, and the exposure of subendothelial tissue factor to plasma factor VII, which ultimately leads to cross-linked fibrin formation. Platelets immediately form a plug at the site of injury; this is called ''primary hemostasis. Secondary hemostasis'' occurs simultaneously: additional coagulation (clotting) factors beyond factor VII ( listed below) respond in a cascade to form fibrin strands, which strengthen the platelet plug. Disorders of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Blood Cell
White blood cells, also called leukocytes or leucocytes, are the cell (biology), cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system. All white blood cells have cell nucleus, nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells (RBCs) and platelets. The different white blood cells are usually classified by cell division, cell lineage (myelocyte, myeloid cells or lymphocyte, lymphoid cells). White blood cells are part of the body's immune system. They help the body fight infection and other diseases. Types of white blood cells are granulocytes (neutrophils, eosinophils, and basophils), and agranulocytes (monocytes, and lymphocytes (T cells and B cells)). Myeloid cells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair. The five cardinal signs are heat, pain, redness, swelling, and Functio laesa, loss of function (Latin ''calor'', ''dolor'', ''rubor'', ''tumor'', and ''functio laesa''). Inflammation is a generic response, and therefore it is considered as a mechanism of innate immune system, innate immunity, as compared to adaptive immune system, adaptive immunity, which is specific for each pathogen. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukocyte Extravasation
Leukocyte extravasation (also commonly known as leukocyte adhesion cascade or diapedesis – the passage of cells through the intact vessel wall) is the movement of leukocytes out of the circulatory system and towards the site of tissue damage or infection. This process forms part of the innate immune response, involving the recruitment of non-specific leukocytes. Monocytes also use this process in the absence of infection or tissue damage during their development into macrophages. Overview Leukocyte extravasation occurs mainly in post-capillary venules, where haemodynamic shear forces are minimised. This process can be understood in several steps: # Chemoattraction # Rolling adhesion # Tight adhesion # (Endothelial) Transmigration It has been demonstrated that leukocyte recruitment is halted whenever any of these steps is suppressed. White blood cells (leukocytes) perform most of their functions in tissues. Functions include phagocytosis of foreign particles, production of anti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemodynamics
Hemodynamics or haemodynamics are the dynamics of blood flow. The circulatory system is controlled by homeostatic mechanisms of autoregulation, just as hydraulic circuits are controlled by control systems. The hemodynamic response continuously monitors and adjusts to conditions in the body and its environment. Hemodynamics explains the physical laws that govern the flow of blood in the blood vessels. Blood flow ensures the transportation of nutrients, hormones, metabolic waste products, oxygen, and carbon dioxide throughout the body to maintain cell-level metabolism, the regulation of the pH, osmotic pressure and temperature of the whole body, and the protection from microbial and mechanical harm. Blood is a non-Newtonian fluid, and is most efficiently studied using rheology rather than hydrodynamics. Because blood vessels are not rigid tubes, classic hydrodynamics and fluids mechanics based on the use of classical viscometers are not capable of explaining haemodynamics. The st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TLR9
Toll-like receptor 9 is a protein that in humans is encoded by the ''TLR9'' gene. TLR9 has also been designated as CD289 (cluster of differentiation 289). It is a member of the toll-like receptor (TLR) family. TLR9 is an important receptor expressed in immune system cells including dendritic cells, macrophages, natural killer cells, and other antigen presenting cells. TLR9 preferentially binds DNA present in bacteria and viruses, and triggers signaling cascades that lead to a pro-inflammatory cytokine response. Cancer, infection, and tissue damage can all modulate TLR9 expression and activation. TLR9 is also an important factor in autoimmune diseases, and there is active research into synthetic TLR9 agonists and antagonists that help regulate autoimmune inflammation. Function The TLR family plays a fundamental role in pathogen recognition and activation of innate immunity. TLRs are named for the high degree of conservation in structure and function seen between mammalian TLRs and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TLR4
Toll-like receptor 4 is a protein that in humans is encoded by the ''TLR4'' gene. TLR4 is a transmembrane protein, member of the toll-like receptor family, which belongs to the pattern recognition receptor (PRR) family. Its activation leads to an intracellular signaling pathway NF-κB and inflammatory cytokine production which is responsible for activating the innate immune system. TLR4 expressing cells are myeloid (erythrocytes, granulocytes, macrophages) rather than lymphoid (T-cells, B-cells, NK cells). Most myeloid cells also express high levels of CD14, which facilitates activation of TLR4 by LPS. It is most well known for recognizing lipopolysaccharide (LPS), a component present in many Gram-negative bacteria (e.g. ''Neisseria'' spp.) and selected Gram-positive bacteria. Its ligands also include several viral proteins, polysaccharide, and a variety of endogenous proteins such as low-density lipoprotein, beta-defensins, and heat shock protein. Palmitic acid and lauric acid a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TLR2
Toll-like receptor 2 also known as TLR2 is a protein that in humans is encoded by the ''TLR2'' gene. TLR2 has also been designated as CD282 (cluster of differentiation 282). TLR2 is one of the toll-like receptors and plays a role in the immune system. TLR2 is a membrane protein, a receptor, which is expressed on the surface of certain cells and recognizes foreign substances and passes on appropriate signals to the cells of the immune system. Function The protein encoded by this gene is a member of the Toll-like receptor (TLR) family, which plays a fundamental role in pathogen recognition and activation of innate immunity. TLRs are highly conserved from ''Drosophila'' to humans and share structural and functional similarities. They recognize pathogen-associated molecular patterns (PAMPs) that are expressed on infectious agents, and mediate the production of cytokines necessary for the development of effective immunity. The various TLRs exhibit different patterns of expression. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD14
CD14 (cluster of differentiation 14) is a human protein made mostly by macrophages as part of the innate immune system. It helps to detect bacteria in the body by binding lipopolysaccharide (LPS), a pathogen-associated molecular pattern (PAMP). CD14 exists in two forms, one anchored to the membrane by a glycosylphosphatidylinositol (GPI) tail (mCD14), the other a soluble form (sCD14). Soluble CD14 either appears after shedding of mCD14 (48 kDa) or is directly secreted from intracellular vesicles (56 kDa). The x-ray crystal structure of human CD14 reveals a monomeric, bent solenoid structure containing a hydrophobic amino-terminal pocket. CD14 was the first described pattern recognition receptor. Function CD14 acts as a co-receptor (along with the Toll-like receptor TLR 4 and MD-2) for the detection of bacterial lipopolysaccharide (LPS). CD14 can bind LPS only in the presence of lipopolysaccharide-binding protein (LBP). Although LPS is considered its main ligand, CD14 also rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
