The immune function of liver

By | April 23, 2012

The immune function of the liver, the liver is the mononuclear phagocyte system, major components, it can into the liver of bacteria, viruses, toxins and other substances, phagocytosis, filtration and other treatment, the liver is the body and therefore one of the largest "filter" is portal vein blood into the body's first line of defense. The immune function of the liver mainly by the mononuclear phagocytes system and liver cells to complete.
First, the liver mononuclear phagocytes system – Kupffer cells
The liver is rich in Kupffer cells, the survival period of 4-16 weeks. Kupffer cells have a strong phagocytosis, phagocytosis, including recognition of their attachment, phagocytosis and digestion process of decomposition of 3. When foreign particles such as bacteria, viruses, toxins, etc. attached to their cell surface, it can extend pseudopodia, surrounded by foreign particles into phagocytic cells and the formation of the phagosome, the phagosome with lysosomes move closer integration between the two. Enzymes in the lysosomes under the influence of foreign bodies are digested hydrolysis. In addition, Kupffer cells also engulfed antigens, but it is different from other phagocytic cells, it does not increase when play phagocytosis immunogenicity of antigen, but can suppress the immunogenicity, which inhibit the immune response in the liver Second, the role of Kupffer cells also have some role in antigen presentation, it can be presented to T cell antigen; Kupffer cells can also produce some of the complement, such as C2, C4 and colony stimulating factor, the surface of Kupffer cells immunoglobulin receptors and complement receptors in the regulation of the immune response and play a role. In addition, superoxide anion production in Kupffer cells of anti-bacterial; produce interferon, play the role of anti-virus.
The immune function of the liver, two, the liver is to produce immunoglobulin and complement the main producers of
Complement in the immune response play an extremely important role. There are 30 kinds of serum complement components, and C2, C4 is the main component of complement, mainly by the liver parenchymal cells and Kupffer cell synthesis.
Liver cell protein synthesis ribosome is the place, some of immunoglobulin (Ig), mainly in the liver. Secretory IgA (SIgA) by the two monomers and secretory IgA (SC) component. SC is a hepatocyte, biliary epithelial cells and epithelial cells synthesized, SC is not only involved in the formation of SIgA and transport, but also are resistant to the protease secretion outside the hydrolysis, so that the biological activity of SIgA from destruction. IgA is the main immunoglobulin in bile, the liver not only with SIgA, and poly intake can actively secreted IgA to bile, so that with the bile duct or intestinal epithelial cells produce the SC combination. Mucosal SIgA is the most important local immune protective factors, it can not only remove the harmful cycle or foreign antigens, but also strengthen the biliary and intestinal immune defense mechanisms, pathogenic enteric pathogens for defensive play an important role.
The immune function of the liver, three liver is dealing with regulation of the immune response to antigen and the important place
The liver can handle the majority of antigens from the intestinal substances such as food, bacteria, viruses, endotoxins, etc., so that they lose their antigenicity. Liver parenchymal cells and liver cells, including sinusoidal wall, the role of exogenous inducing agent, it can be secreted in some biologically active substances (such as membrane insulin-like growth factor -1, AFP, liver immunosuppressive factors, etc.) involved in the regulation of immune responses. In addition, the liver also has a role in inducing immune tolerance, which is a defense mechanism that one can prevent systemic violations of hazardous substances by the gut, on the other hand can also avoid the body's immune response to foreign antigens to prevent hypersensitivity response, causing tissue damage

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